Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
453 AM AST Tue Oct 23 2018

.SYNOPSIS...Weak flow in the synoptic pattern and a frontal
boundary that persists to the north with modest moisture will
maintain scattered showers across the forecast area. Heavier
showers will form in the western sections of Puerto Rico each
afternoon. Low level flow will make a gradual shift from Tuesday
to Thursday from east northeast to east southeast or southeast and
will not return until late next weekend. Showers will favor the
northwest and interior of Puerto Rico each afternoon but will be
sparse in the U.S. Virgin Islands.

&&

.SHORT TERM...Today through Thursday...

A dry mid to upper-level ridge pattern will continue to prevail
across the local area through the short term period, keeping
thunderstorm potential low. However, decent low-level moisture
from the surface through 700 mb will be enough to generate areas
of shower activity across the region. During the morning hours,
some passing showers over the surrounding waters will continue to
briefly affect portions of northern and eastern PR and the USVI.
Then, during the afternoon hours, the available moisture will
combine with diurnal and local effects to result in the
development of showers across interior and western PR as the flow
shifts to a more easterly component. Given that the surface to 3
km wind flow is expected to diminish to around 10 kts, the shower
activity that does develop will tend to move slower than the last
several days, therefore, the potential for urban and small stream
flooding will be higher.

On Wednesday and Thursday, the steering flow will diminish even more
to around 5 kts. Therefore, the showers that develop will be slow
movers and will have the potential to produce more significant
rainfall accumulations, especially with afternoon convection.
Therefore, the potential exists for more urban and small stream
flooding as well as mudslides in areas of steep terrain. The area
with the highest potential for more significant rainfall will be
across the cordillera central of PR.

.LONG TERM...Friday through Tuesday...
The weak boundary north of the area at lower levels will dig into
the northern part of the Tropical Atlantic just east of the
Leeward Islands on Friday and Saturday. A weak trough will also
move south of Puerto Rico and the Mona Channel in the southern
Caribbean on Friday. Precipitable water will decline from 1.8 to
1.4 inches from Friday to Sunday. Shower activity will be fairly
robust during the afternoons in western and interior Puerto Rico
these days, but thunderstorms are not expected due to limited
instability and drier mid levels. Showers over the local waters
and the U.S. Virgin Islands will not be as plentiful as during the
previous last several days. A weak low at 700 mb is expected to
approach the area from the northeast on Monday and may bring the
back edge of the boundary that dug into the tropical Atlantic
back over us to increase showers on Monday. Although moisture will
increase somewhat Monday and Tuesday, the increase will not be
particularly significant, except that flow will again have a weak
northerly component and overnight showers will favor the north and
northeast coasts of Puerto Rico and the southwest during the
afternoons. Urban and small stream flooding during this period
should be isolated and confined to the western and interior
sections of Puerto Rico during the afternoons. Mudslides of a
limited nature cannot be ruled out as daily rains are keeping
some soils saturated.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
the terminals through the forecast period. Sct SHRA over the
Atlantic waters may briefly affect TJSJ/TIST terminals during the
early morning hours. Between 23/16-22Z SHRA expected over interior
and western PR, which could affect TJMZ and TJPS terminals.
Surface winds will continue from the E-NE below 15 kts through
23/14z, with sea breeze variations expected to develop afterwards.

&&

.MARINE...Conditions will continue to improve as seas diminish. A
4 foot swell will arrive in the area overnight tonight from the
north northwest and be pretty much over by late Wednesday. Rip
current risk will still be moderate for many exposed northern
coasts during the next week, otherwise a low risk is anticipated.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 88 77 / 50 50 30 30
STT 88 78 88 78 / 30 40 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
441 AM AST Wed Oct 24 2018

.SYNOPSIS...Mid to upper-level ridge pattern is expected to remain
entrenched across the forecast area through at least mid-week next
week, inhibiting deep and widespread convection from developing.
However, the combination of low-level moisture will combine with
local effects and daytime heating to result in the development of
afternoon showers over interior and western portions of Puerto
Rico each day.

&&

.SHORT TERM...Today through Friday...Mid to upper level ridge
will slightly erode across the region today through Friday as a
short wave trough moves eastward across the west and central
Atlantic. A broad surface trough extending northwards across the
region and an elongated area of low pressure northeast of the
Northern Leeward islands, will maintain a fairly light wind flow
across the forecast area through at least Thursday. Thereafter, a
surface high pressure ridge builds across the west and southwest
Atlantic through Friday to increase the east to northeast wind
flow across the region.

Recent satellite imagery and doppler radar and earlier 24/00z upper
air sounding, continued to suggest that patches of low level
moisture with embedded showers will continue to move through the
region in the prevailing light to moderate east to northeast wind
flow through the morning hours. These passing tradewind showers will
affect the north and east coastal sections of the islands from time
to time producing periods of moderate to locally heavy rains.
Gradual improvement is expected by late morning with diminishing
clouds and shower activity. Satellite derived precipitable water
values as well as model guidance both suggest near normal PWAT
values across the region for the next few days and should continue
to range between 1.50 to 1.70 inches. That said, the available
moisture along with local and diurnal effects and good sea breeze
variations, expect afternoon shower development with only a slight
chance of an isolated thunderstorm over the west interior. This
pattern is expected through Thursday with periods of moderate to
locally rainfall possible each day. Due to saturated and loose soil
across much of the interior sections of Puerto Rico, mudslides will
remain possible in areas of steep terrain...as well as urban and
small stream flooding. For the USVI, passing early morning showers
will be followed by mostly sunny to partly cloudy skies with only
isolated afternoon showers expected in some areas. By Friday an
increase in trade wind moisture is forecast at this time and
therefore supporting a better chance for early morning and afternoon
convection over western Puerto Rico.

.LONG TERM...Saturday through Wednesday...

Not much change is expected during the long term period as the
aformentioned mid to upper-level ridge pattern will continue to
influence our local weather pattern, inhibiting the development of
deep and widespread convection. However, afternoon convection is
still expected to develop over portions of interior and western
Puerto Rico each day as sufficient low-level moisture will
combine with daytime heating and local effects to result in the
development of showers. Across the rest of the forecast area, some
passing showers are expected during the overnight and early
morning hours across portions of northern and eastern PR, the
USVI, and surrounding waters.

It is important to mention that the steering flow is expected to
remain weak, at around 10 knots or less, through the middle of
next week, therefore, the showers that do develop in the afternoon
are expected to be slow movers and may pose a risk for urban and
small stream flooding as well as mudslides in areas of steep
terrain.

&&

.AVIATION...VFR at all terminals. -SHRA/SHRA ovr regional waters and
en route btw islands. SCT ocnl Bkn cld lyrs nr FL025...FL080...Few
tops btw FL100-FL150. Mtn top obscr til 24/12z in -SHRA/low cig.
VCSH at TJSJ/TIST/TISX and Nrn Leeward islands til 24/14z. FM 24/17z-
24/22z VCSH at TJSJ/TJBQ/TJMZ with SHRA/+SHRA ovr central and
western interior of PR. Winds lgt/vrb bcmg mainly fm ENE at 10-15KT
with occasional hir gusts and sea breeze variations.

&&

.MARINE...Light to gentle winds will keep seas below 5 feet
across the regional waters during the next several days. There is
a moderate risk of rip currents across the northern beaches of
Puerto Rico and Culebra as well as across the northwestern beaches
of Saint Thomas for today.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 87 78 / 30 30 20 30
STT 89 77 88 77 / 30 40 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
412 AM AST Thu Oct 25 2018

.SYNOPSIS...Mid to upper-level ridge pattern will hold across the
forecast area through the first part of next week. This will
continue to limit the development of deep and widespread
convection, however, locally and diurnally induced showers are
still expected to develop each afternoon across portions of
interior and western PR as there will still be sufficient low-
level moisture available. The ridging is expected to erode
by mid-week next week as a deep trough moves across the western
Atlantic.

&&

.SHORT TERM...Today through Saturday...Satellite imagery and
recent model guidance continued to suggest a slight erosion of the
mid to upper level ridge, as a short wave trough will move
eastward across the western Atlantic just north of the region.
However, the ridge aloft is to reestablish and build overhead by
Friday and into the weekend favoring an increasing low level cap
inversion which is expected to hold in place through the period.
Near normal layered precipitable water values will persist across
the region, with a weak easterly trade wind flow to dominate the
area through Friday. Winds are then expected to return from the
east-northeast by Saturday.

Due to the fairly loose pressure gradient across the region, the low
level steering wind flow will remain very weak. Given the present
and expected weather pattern, expect sufficient low-level moisture
fragments to be transported across the region over the next few
days. The available moisture, along with good sea breeze variation
and local effects will support afternoon convection each afternoon.
Some of the afternoon shower development may give way to isolated
thunderstorms, mainly over parts of the central interior and west
PR. The afternoon shower activity should then drift north and south
over the coastal municipalities before diminishing and dissipating
around sunset. Afternoon convection will produce periods of heavy
rainfall and possible isolated thunderstorms each day. Therefore
urban and small stream flood potential will remain high across the
interior and west sections of PR. Mudslides in areas of steep
terrain will remain possible due to lose and saturated soil.

.LONG TERM...Sunday through Thursday...

Model guidance continues to be consistent in showing the mid to
upper-level ridging pattern persisting through the first half of
next week. This will continue to inhibit deep convection from
developing. However, there will still be sufficient low-level
moisture available to combine with daytime heating and local
effects to result in the development of shallow convection over
portions of interior and western PR each afternoon. Given that the
steering flow will continue to remain weak, any afternoon showers
that develop will be slow movers and may continue to pose a risk
for urban and small stream flooding as well as mudslides in areas
of steep terrain.

By the middle of next-week, a deep trough moving across the
eastern United States into the western Atlantic will
erode the mid to upper-level ridge. This will increase the
instability aloft and allow for better moisture to move over the
region. Therefore, the potential exists for better thunderstorm
activity with afternoon convection.

&&

.AVIATION...VFR thru forecast prd. SCT ocnl BKN cld lyrs nr FL025...
FL050...FL090 til 25/12z. SHRA/+SHRA ovr coastal waters and en route
btw islands. Few tops btw FL100-FL180 MAINLY ovr Caribbean waters.
L/lvl wnds LGT/VRB blo FL200 bcmg fm N-NW abv and incr w/height. Sfc
wnds calm to lgt/vrb. No sig AVN wx impacts attm for local flying
area.

&&

.MARINE...Light easterly winds will continue to prevail across the
regional waters through the end of the work week, maintaining
seas under 5 feet. A moderate risk of rip currents continues for
the northern beaches of Puerto Rico and Culebra as well as the
northwestern beaches of Saint Thomas.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 87 76 / 20 30 40 20
STT 88 76 88 77 / 20 40 40 20

[cycloneye]

Area Forecast Discussion.
National Weather Service San Juan PR
426 AM AST Fri Oct 26 2018

.SYNOPSIS...Mid to upper level ridge across central Caribbean and
the southwestern Atlantic will continue to extend across the region
to maintain an overall dry and stable anticyclonic flow. Surface
high pressure ridge across the west Atlantic and a developing low
pressure system across the central Atlantic will maintain fairly
light easterly winds across the region today. The winds will
slightly increase over the weekend as the surface high builds
north of the region. A frontal shear line will continue to sink
southwards and reach the local Atlantic by early Saturday. Shallow
trade winds moisture and occasional light to moderate showers
will continue to affect the local waters and portions of the north
and and east coastal sections of the islands

&&

.SHORT TERM... Today through Sunday...
Not much change in the overall synoptic pattern is expected for
today as a mid to upper- level ridge continues entrenched across
the southwestern Atlantic, stretching its influence over the
region. Even though the mid to upper-levels remain fairly dry,
there is still sufficient moisture between the surface to 700 mb
that, during the morning hours, some passing trade winds showers
may affect portions of eastern PR and the surrounding waters.
Afterwards, this low-level moisture will combine with daytime
heating and local effects to result in the development of moderate
to heavy showers across the central and western interior of
Puerto Rico for this afternoon. Almost all of the High Resolution
models indicate this scenario occurring for this afternoon. Some
isolated thunderstorms cannot be ruled out with the stronger
activity. Due to the recent heavy rainfall activity this week
across the interior of the island, the soils remain saturated and
loose. Therefore, a prolonged period of heavy rainfall would most
likely result in urban and small stream flooding as well as mudslides
in areas of steep terrain. Activity is expected to diminish around
sunset. Across the USVI, most of the day should be fairly dry.

On Saturday, moisture along the shearline associated with the
remnants of a frontal boundary, currently located near 20N, is
expected to move southwards and affect the forecast area.
Therefore, an increase in shower activity as well as the winds
shifting from the northeast are expected. Scattered showers will
be concentrated across the Atlantic waters and portions of
northern and eastern PR and the USVI during the morning hours.
Afterwards, the associated moisture will combine with daytime
heating and local effects to result in the development of showers
across the central interior and the southern slopes of Puerto Ric
during the afternoon hours.

As the moisture field associated with the remnants of the frontal
boundary moves away late Saturday night, a drier air mass is
expected to encompass the region for Sunday. Therefore, mainly
fair weather conditions are expected across most of the region.
However, locally and diurnally induced showers could develop
across the southwestern quadrant of Puerto Rico during the
afternoon hours, however, at this time significant accumulations
are not anticipated.

.LONG TERM...Monday through Saturday...
Overall weather pattern and recent model guidance continued to be
consistent in suggesting that the mid to upper-level ridge pattern
will persist through at least Tuesday. As a result, deep layered
moisture will continue to be limited supporting fairly stable
conditions aloft. However, there will still be sufficient low-level
moisture available to combine with diurnal heating and local effects
to result in the development of afternoon convection over portions
of interior and western PR each afternoon. Mostly isolated afternoon
showers can be expected elsewhere including over the USVI.

By the middle of next-week, a long wave trough is to become amplified
across the western Atlantic and will erode the mid to upper- level
ridge. This will increase the instability aloft and allow for better
moisture pooling across the region. This along with the development
of an induced surface trough across the northeastern Caribbean, and
a moist east to southeast wind flow will increase the potential for
more frequent early morning showers and enhanced afternoon thunderstorm
activity across the islands and coastal waters during the latter part
of the forecast period.

&&

.AVIATION...Mainly VFR conditions will prevail across all terminal
sites through the forecast period. SHRA expected over the central
and western interior of PR between 26/16Z-22Z, which could affect
TJMZ and TJBQ terminals. Easterly winds of 10kts or less expected
blw FL100 with local sea breeze variations developing after
26/14Z.


&&

.MARINE...Mariners can expect seas between 3 to 5 feet with light to
moderate winds between 5 to 15 knots through the weekend.A slight
increase in winds and seas is expected by Monday and Tuesday with
the arrival of a northeasterly swell and high pressure ridge
building north of the region.

There`s a moderate risk of rip currents for the northern beaches
of Puerto Rico today.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 76 88 77 / 20 40 40 40
STT 87 77 88 76 / 20 50 50 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Sat Oct 27 2018

.SYNOPSIS...
Stable and relative dry weather conditions prevailed across the
forecast area overnight, as a mid to upper level ridge continued to
extends across the region from the central Caribbean and southwest
Atlantic. As the surface high pressure ridge continued to build north
of the region across the western Atlantic, shallow low level moisture
along a frontal shear line was being pushed southwards across the
region in the prevailing east to northeast steering flow. Occasional
trade wind showers embedded in the wind flow continued to affect the
coastal waters and parts of the north and east coastal sections of
some of the local islands. The shower activity was mostly of light
to moderate intensity.

&&

.SHORT TERM...Today through Monday...
East to East-Northeast moderate wind flow is expected to prevail
through the weekend, but the local winds are expected to diminish
on Monday as the subtropical storm Oscar is expected to be to the
northeast of the local islands. For the next few days the overall
available moisture is expected to be below normal, and a ridge in
the upper levels is expected to prevail over the local area as
well with an upper trough to the east of the local islands. This
setup generally would yield fairly benign weather, however, the
relatively light steering winds, the local effects and the diurnal
heating will combine with the limited but still enough moisture
to cause the development of showers across central to western PR
in the afternoon. With this activity, a brief thunderstorm will
not be ruled out since it has been happening the past few days and
the high resolution guidance is suggesting the possibility of
thunderstorms this afternoon.

Sunday looks slightly drier with less available moisture and
stronger ridge aloft, causing a more stable atmosphere and
therefore less significant shower activity. However, once again on
Monday, the local guidance suggests better chances for showers and
thunderstorms across central and western PR in the afternoon hours
as the winds weaken and the ridge in the upper levels weakens as
well. That said, just about every night and early morning will have
isolated and brief showers across the local area. The USVI should
observe brief showers and possibly showers across the western
sections of the islands in the afternoon hours as they stream off
the islands.

.LONG TERM...Tuesday through Sunday...
Recent model guidance initialized well and continued to suggest that
the mid to upper- level ridge pattern will persist an influence the
local weather pattern through Tuesday. Deep layered moisture will
therefore be limited as the region will remain on the convergent
side of an upper trough therefore supporting stable conditions
aloft. However, there will still be sufficient low- level moisture
transport to combine with local effects and daytime heating to
favor afternoon convection mainly over parts of the interior and
west sections of Puerto Rico. Mostly isolated afternoon showers
can be expected elsewhere including over the USVI.

By Wednesday, and during the rest of the work week, a broad long
wave trough is forecast to spread and become amplified across the
western Atlantic while erode the mid to upper- level ridge. This
will increase the instability aloft and support better moisture
pooling across the region. The change in the upper level pattern
along with the development of an induced surface trough across the
northeastern Caribbean, and a moist east to southeast wind flow
will increase the potential for more frequent early morning
showers and isolated afternoon thunderstorms across the islands
and coastal waters through at least Thursday. By Friday and into
the weekend, a more seasonal weather pattern is forecast. Surface
high pressure ridge is to build north of the region along with
the strengthening of the mid to upper level ridge which will also
spread eastwards across the forecast area. Consequently, a drier
and stable weather pattern with light to moderate east to northeasterly
winds will prevail. Occasional passing early morning showers over
the local waters and some coastal areas can be expected, with locally
and diurnally induced afternoon showers mainly in isolated areas over
the interior and west to southwest section of PR. Elsewhere mostly
sunny fair weather skies should prevail each day.

&&

.AVIATION...Mainly VFR conditions will prevail across all the
terminals through 27/18Z with brief -SHRA across the general area
causing VCSH across most of the local terminals early in the
morning. Afternoon SHRA/TSRA, over PR could result in VCTS at TJMZ
and VCSH at TJSJ and TJPS. Light and variable winds will continue
through 27/12Z, increasing from the east-northeast at 10-15KT with
sea breeze variations developing by 27/14z.


&&

.MARINE...Seas will range from 3 to 5 feet with east to northeast winds of
5 to 15 kts.

There is a moderate risk of rip currents for the northern beaches of
Puerto Rico.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 86 76 / 30 30 30 30
STT 88 77 87 76 / 30 30 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
430 AM AST Sun Oct 28 2018

.SYNOPSIS...Mid to upper level high pressure ridge will continue
to extend across the region from the west and southwest Atlantic
through early next week. Surface high pressure ridge across the
west Atlantic and the distant Subtropical Storm Oscar located over
the Central Atlantic will maintain a light to moderate
northeasterlywind flow across the forecast area for the next
several days. Patches of shallow low level moisture will continue
to move across the region bringing periods of occasional showers
to the coastal waters and portions of the islands.

&&

.SHORT TERM...Today through Tuesday...
East-Northeast to Northeast moderate wind flow is expected to
prevail today, but the local winds are expected to diminish on
Monday and Tuesday as the current subtropical storm Oscar...which
his expected to transition into a tropical storm and
strengthen...moves into the northeast of the local islands and forms
a sort of col over the local area. The overall available moisture is
expected to be below normal for the next few days, and a ridge in
the upper levels is still expected to prevail over the local area as
well with an upper trough to the east of the local islands. This
setup should yield fairly benign weather with the exception of
showers developing across areas of convergence in Puerto Rico in the
afternoon hours. This means that this afternoon the afternoon
showers should be in the south to southwestern sections of PR, while
Monday and Tuesday the showers should be in the interior sections of
the island. The USVI should observe mainly brief showers. The high
resolution guidance is rather bullish on the rainfall but it did not
materialize yesterday and nothing really has changed in the overall
big picture, so we decided to be more conservative in the rainfall
amounts and left the thunderstorms out of the forecast.


.LONG TERM...Wednesday through Monday...
Wednesday through early Friday, A broad mid to upper level trough
is still forecast to spread eastward and become amplified across
the western Atlantic while eroding the mid to upper- level ridge
overhead. This will increase the instability aloft and support
better low level moisture pooling across the region. The change
in the upper level pattern along with the development of an
induced surface trough and a moist east to southeast wind flow
accompanying a weak tropical wave, will also increase the
potential for more frequent shower activity during the morning
hours and isolated afternoon thunderstorms across the islands and
coastal waters through the end of the work week. By late Friday
and into the weekend a more seasonal weather pattern is forecast.
Surface high pressure ridge is forecast to build north of the
region along with the reinforcing of the mid to upper level ridge
which will spread across the forecast area. For now, a drier and
stable weather pattern with light to moderate east to northeasterly
winds will prevail through Monday. Occasional passing early morning
showers over the local waters and some coastal areas can be expected,
with locally and diurnally induced afternoon showers in isolated
areas over the interior and west to southwest section of PR. Elsewhere
mostly fair weather skies and overall sunny conditions should prevail
each day with limited shower activity during the daytime.

&&

.AVIATION...Mainly VFR conditions will prevail across all the
terminals through 28/18Z with brief -SHRA across the general area
causing VCSH across some of the local terminals early in the
morning. Afternoon SHRA over PR could result in VCSH at TJMZ and
TJPS. Light and variable winds will continue through 28/12Z,
increasing from the east-northeast to NE at 10KT with sea breeze
variations developing after 28/13Z.


&&

.MARINE...Mariners can expect seas between 2 and 5 feet with light
to moderate winds between 5 to 15 knots. A moderate risk of rip
currents is expected across the north facing beaches of Puerto
Rico, including Vieques and Culebra.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 87 76 / 30 30 30 30
STT 88 77 87 77 / 20 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
454 AM AST Mon Oct 29 2018

.SYNOPSIS...Hurricane Oscar, now about 620 miles to the NNE of the
northern Leeward islands will bring a northeast swell today into
Tuesday and will weaken the local pressure gradient, causing light
winds early this week. Lower than normal moisture is expected for
the next several days, but showers are still expected across the
local islands, mainly across portions of Puerto Rico in the
afternoon hours and brief showers across the local waters, USVI,
and north and eastern Puerto Rico in the overnight and early
morning hours.

&&

.SHORT TERM...Today through Wednesday...

Partly to variably cloudy skies prevailed across the forecast area
overnight and early this morning with frequent passing showers
observed across the north and east coastal areas of Puerto Rico, the
northern USVI as well as the surrounding waters. However, rainfall
accumulations associated with these showers were minimal. Winds were
from the east northeast at 10 mph or less with coastal temperatures
in the mid to upper 70s.

A mid to upper level trough across the central Atlantic into the
eastern Caribbean with associated axis located east of the forecast
area will continue to erode through the forecast period.
Hurricane Oscar located near 25.7N and 57.8W, or about 620 miles
northeast of the northern Leeward Islands is expected to remain
far away from our area. Under the convergent/subsident side of the
mid to upper level trough and PW values below the normal range,
continue to expect locally induced afternoon showers over the
Cordillera Central and the southern slopes of Puerto Rico as well
as a few showers embedded in the trades affecting the north and
east coastal areas. The chance for showers and isolated
thunderstorms will increase on Wednesday as moisture increases and
subsidence aloft collapses. A light to gentle east northeast wind
flow is still expected across the forecast area through at least
midweek, therefore afternoon showers will be slow movers
increasing the potential for urban flooding.

.LONG TERM...Thursday through Tuesday...

Overall lower than normal moisture is expected for the long term.
The local winds will be from the east for the latter part of the
week, turning to the northeast from Sunday into the early days of
the following workweek. Upper level zonal flow expected until
Friday when an upper low across the western central Atlantic
gradually strengthens and moves closer to the local islands,
causing its associated trough to have its axis just west of the
local area, then the axis will remain remain over the local
islands through Saturday, then by Sunday night it should be to
the east of the local islands. This is the time where the best
moisture --albeit still lower than normal-- is expected across the
local islands. So the best chance of showers and perhaps a few
thunderstorms may occur next weekend if the models were to verify.
A surface high pressure will move to the north of the local
islands late this week, causing east to east southeast winds. Then
a surface low pressure will develop across the central Atlantic
and move west, bringing much drier air to the local area from
Sunday into the early part of next week.

&&

.AVIATION...VFR conds are expected to prevail at all TAF sites with
a few -RA in and around the USVI terminals as well as JSJ in the
morning. Aft 29/16z VCSH likely at JMZ/JPS. ENE winds at around 10
knots with some sea breeze variations.

&&

.MARINE...Northeasterly swell from Hurricane Oscar will invade the
local waters today through Tuesday, causing choppy seas up to 6
feet. There is a moderate risk of rip currents for the northern
beaches of PR and Culebra as well as the north and eastern
beaches of Saint Croix. However, there may be a high risk of rip
currents across these beaches tonight into Tuesday.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 87 77 / 40 40 40 40
STT 87 76 87 76 / 40 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
505 AM AST Tue Oct 30 2018

.SYNOPSIS...Drier than normal available moisture with very light
winds expected as Hurricane Oscar continues to move to the north
and further from the local area. Light easterly winds to return on
Wednesday. Stable upper levels should inhibit thunderstorm
potential for the next few days. However, afternoon rain are
still expected over Puerto Rico.

&&

.SHORT TERM...Today through Thursday...

Clear to partly cloudy skies prevailed across the forecast area
overnight and early this morning with passing showers noted over the
northern USVI and the surrounding waters. Winds were light and
variable with coastal temperatures in the low to mid 70s.

Deeper convective instability is expected across the forecast area,
particularly Wed-Thu as a weak upper trough meanders north of the
area. At lower levels, light steering winds to continue. Therefore,
under PW below normal and the aforementioned pattern, still expect
sea breeze convergence inducing showers across the interior of
Puerto Rico this afternoon. The intensity and areal coverage of
afternoon showers will then increase Wed and Thu as well as the
chances for thunderstorms. The afternoon showers will be slow movers
and as a result there is a risk for urban flooding.

.LONG TERM...Friday through Wednesday...

Long term guidance did not change much from what it was indicating
yesterday, the overall moisture expected for the long term should
be below normal, except for late Saturday into Sunday. The local
winds are expected to be from the east for the latter part of the
week into the weekend, turning to the northeast on Monday and
through the first half of the following workweek. Upper level
zonal flow expected through Friday then an upper low across the
western central Atlantic gradually strengthens and moves closer to
the local islands by Saturday, causing its associated trough to
have its axis just over the local area, then by Sunday night the
axis should be to the east of the local islands. This happens to
be at the time that the best moisture is expected, getting close
to normal for the time of year. So the best chance of showers and
perhaps a few thunderstorms may occur next weekend if the models
were to verify, this time we decided to add isolated
thunderstorms into the forecast since there has been some
consistency int he guidance for a couple of days now. A surface
high pressure still appears that it will move to the north of the
local islands late this week, causing east to east southeast
winds. Then a weak surface trough may develop north of the local
islands by early next week, causing a wind shift to a
northeasterly direction.

&&

.AVIATION...VFR conds are expected to prevail at all TAF sites with
a few -RA in and around the USVI terminals early in the morning. Aft
30/16z VCSH likely at JMZ/JPS and possibly JSJ. Light and variable
winds to continue.

&&

.MARINE...The local guidance seems to be overestimating the wave
heights a little bit, and the latest guidance indicated that seas
would be below 7 feet. For that reason the small craft advisory
for the offshore Atlantic waters was cancelled. Seas are expected
to be up to 6 feet and small craft operators are urged to exercise
caution. Winds across the local waters are expected to be
generally light, up to 10 knots and variable.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 87 76 / 40 40 40 40
STT 86 75 87 77 / 20 30 40 40

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
510 AM AST Wed Oct 31 2018

.SYNOPSIS...Light to gentle winds will gradually become moderate
to fresh by Friday. Shower activity will slowly increase through
the end of the week under trofiness and low level moisture advection.
Drier weather conditions are expected once again the next work
week.

&&

.SHORT TERM...Today through Friday...

A drier weather pattern is expected to continue through Thursday
with easterly winds of 5 to 10 mph. At the upper levels, a jet
has developed just to the north of Puerto Rico and will continue
to strengthen, and move closer to the area through Thursday. The
jet will bring a weak frontal boundary to the north of Puerto Rico
as well today, this weak front and jet will give a boost to a
relative quiet pattern by providing weak upper-level support to
developing showers today through Friday.

Moderate to light showers are forecast to develop across portions of
the interior, and western areas of Puerto Rico today and Thursday.
These showers will move slowly due to weak steering flow at 0-3 km;
guidance suggest this weak low-level steering flow will continue
through Friday.

Friday a trough is forecast to amplify to the north of Puerto
RIco while providing extra moisture to the region. This increase
in moisture and instability, as well as local and diurnal effects,
will cause an increase in showers and isolated thunderstorms
Friday afternoon.

.LONG TERM...Saturday through Thursday...

TUTT across the central Atlantic and into the eastern Caribbean will
prevail through the forecast cycle with its associate area of low
pressure meandering northeast of the local islands. At lower levels,
a broad high pressure will hold through Tuesday. As this feature
moves northeastward while weakening, an induced surface trough will
prevail across the eastern Caribbean Wednesday onwards. At this
time, best moisture advection is expected Sat-Sun coinciding with
the best divergence aloft. TUTT low is then expected to relocate
well east of the forecast area with the local islands remaining
under its convergent side. Therefore, there is a chance for
organized convection the upcoming weekend, returning to a drier
weather pattern Monday onwards.

&&

.AVIATION...VFR conditions will prevail across all the terminals
through 31/16Z then SHRA possible across the interior sections of
PR through 31/22z. These SHRA could cause brief MVFR conds due to
+SHRA with conds clearing by 31/22Z. Sfc winds will be light and
variable today.

&&

.MARINE...Tranquil marine conditions will continue to prevail
across the local waters with seas below 5 feet and winds up to
10 knots. Winds and seas are expected to increase during the
weekend as well as the chance for shower and thunderstorm activity
across the local waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 87 77 / 20 20 30 30
STT 87 76 87 76 / 10 20 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
430 AM AST Thu Nov 1 2018

.SYNOPSIS...There is a chance for showers and thunderstorms
during the next several days as moisture increases, an old
frontal boundary approaches the area, and an upper level
trough moves across the area.

&&

.SHORT TERM...Today through Saturday...

Late in the evening showers and isolated thunderstorms developed
over portions of the interior, and northern areas of Puerto Rico.
These showers and isolated thunderstorms were enhanced by the
subtropical jet which provided upper-level divergent. TJUA Dual
Pol storm total accumulations shows rainfall totals ranged from 2
to 4 inches in the aforementioned areas. Due to the moderate to
heavy rainfall several flood advisories were issued. Since then
showers have weakened across the area, but some mid to upper level
clouds remain.

A rather stable weather pattern will transition to an unsettled
weather pattern; produced by a weak trough to the north of Puerto
Rico, as well as a strong subtropical jet that is forecast to
continue across the region through Saturday. The Subtropical jet
will provide sufficient upper level divergent aloft over portions of
northern, interior and western areas Puerto Rico during the
afternoon which will induce shower and thunderstorm development.
However, showers are possible across the eastern areas of Puerto
Rico and areas east during the morning hours.

The unstable conditions are depicted by GFS which has 500 mb
temperatures decreasing to minus 10 degrees C on Friday, as well as
increasing lapse rates from 700 to 500 mb. Additionally, Galvez-
davison index shows values of 25 today through early Friday, but
values increase to 35 late friday afternoon until Saturday. Values
of 25 to 35 means there is potential for scattered thunderstorms
or shallow convection across the forecast area. Guidance suggest
the best instability will be late Friday night into Saturday.
However, this depends on the proximity of the trough to the Puerto
Rico any deviation in the position could require a minor forecast
change in thunderstorm coverage for some areas. At this time this
forecast will follow recent guidance that shows the trough moving
over Puerto Rico. More importantly moderate to heavy rainfall
could cause urban and small stream flooding, therefore if you see
flooded roadways or areas that are flooded remember to turn around
don`t drown.

.LONG TERM...Sunday through Friday...

TUTT low across the central Atlantic and into the eastern
Caribbean will hold through the forecast cycle. At lower levels,
moderate east northeast winds will prevail through Wednesday
becoming gentle by the end of the work week as an induced surface
trough develops across the eastern Caribbean. Latest guidance
suggested PW values remaining near normal values much of the
forecast period except on Tuesday when is expected to be slightly
below the normal range.

Long term forecast is highly dependent on the exact location of
the aformentioned TUTT and associated axis. At this time, best
divergence aloft is expected Sun-Mon as well as Thu as the axis
relocates west of the local islands. Therefore, organized
convection likely to be observed Sun-Mon with a more seasonal
weather Tue-Wed. By the end of the week, the chance for showers
and thunderstorms increases once again.

&&

.AVIATION...VFR conditions will prevail across all the terminals
through 01/15Z then SHRA/VCTS are possible across the interior and
western areas of PR through 01/22z. These SHRA/VCTS could cause
brief MVFR conds due to +SHRA with conds clearing by 01/22Z . Sfc
winds will be light and variable today.

&&

.MARINE...Seas will continue between 3 and 5 feet across the
Atlantic waters and local passages today, elsewhere between 2
and 4 feet. Winds will be out from the east at 5 to 15 knots. An
old frontal boundary approaches the area Friday and Saturday. This
will cause winds and seas to increase during the weekend as well
as the chance for shower and thunderstorm activity.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 88 78 / 40 40 60 60
STT 88 77 88 76 / 40 40 50 60

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
500 AM AST Fri Nov 2 2018

.SYNOPSIS...Wet and unstable weather conditions on tap through
early the next week. Weather conditions improving Wednesday
onwards.

&&

.SHORT TERM....Today through Sunday...

A wetter weather pattern is progged today through early Sunday.
The trough which has remained north of Puerto Rico is expected to
strengthen as a result of curvature and shear vorticity in the
base of the trough. Model guidance shows a low closing off over
Puerto Rico and the U.S. Virgin Islands later tonight which will
weaken the inversion that has persisted since early this weak, by
allowing deep organized convection to develop and persist through
early Sunday. Additionally, 500 mb vorticity as well as 250 mb
wind divergence will begin to increase today and reach a peak
early Sunday morning. Therefore expect moderate to heavy rainfall
to start on Saturday afternoon and linger into early Sunday
morning due to increasing instability and low-level moisture.

Guidance has been consistent on the evolving weather pattern since
early this week, and confidence is high that moderate to heavy
rainfall will develop across the eastern, interior and western
areas of Puerto Rico, as well as the U.S. Virgin Islands this
weekend. During the weekend moderate to heavy rainfall could cause
urban and small stream flooding and ponding of water on roadways,
as well as mudslides.

.LONG TERM....Monday through Saturday...

Long term forecast continues to be highly dependent on the exact
location of TUTT low which is expected to prevail across the central
Atlantic and into the eastern Caribbean much of the forecast
cycle. Latest guidance indicated TUTT axis west of the local
islands Monday, but relocating east of the area by Wednesday
afternoon. This feature is then expected to slowly dissipates by
the end of the work week with a weak ridge pattern building in
from the west during the weekend. At lower levels, moderate to
fresh east northeast winds will prevail through Wednesday becoming
light to gentle by the end of the work week as an induced surface
trough establishes across the eastern Caribbean. At this time, best
moisture advection is expected Mon-Tue.

Under this evolving pattern, the highest chance for organized
convection likely Mon-Tue under moisture exceeding the normal
range which is 1.75 inches combined with divergence aloft. A more
seasonal weather pattern is expected Wednesday onwards with trade
wind showers across the north and east coastal areas of the local
islands at times.

&&

.AVIATION...Mostly VFR conds expected across all terminals sites
through 02/15Z, then SHRA/VCTS possible across terminal sites TJSJ,
TJBQ, and TJMZ until 02/22Z. SHRA/VCTS could cause MVRF conds due
to +SHRA until 02/22Z. Sfc winds out of the east at 10 to 15 kts
with higher gusts possible due to SHRA/VCTS.

&&

.MARINE...Increasing winds will bring hazardous seas across the
Atlantic waters and Caribbean Passages today into the upcoming
weekend with seas up to 8 feet across the offshore Atlantic
waters. SCAs are in effect across these waters through at least
Sunday. There is also a high risk or rip currents along the north
facing beaches of Puerto Rico, Culebra and Saint Croix.

&&

.HYDROLOGY...Under deepening trough and moisture pooling across
the forecast area, environmental conditions will become highly
favorable and conductive for heavy rains across the forecast area,
particularly across USVI and eastern Puerto Rico during the
weekend.

The 7-day average streamflows retrieved from the USGS river gauge
network indicates most of the streamflow across Puerto Rico
between the 25th and the 90th percentile which is near to above
normal. However, there are streamflows running below the normal
range; most of them in the Carraizo basin. Soil saturation is
observed mainly across the western interior of Puerto Rico in the
vicinity of Utuado.

After considering latest guidance and recent observations, there
is an increasing risk for urban and small stream flooding the
upcoming weekend. However, sharp river rises and mudslides cant
be ruled out.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 78 85 76 / 60 60 60 60
STT 87 77 88 77 / 60 60 60 60

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
447 AM AST Sat Nov 3 2018

.SYNOPSIS...
A moist unsettled pattern will prevail today through late Sunday;
with showers and thunderstorms across most of the local area.
This unsettled weather is occurring due to increasing low-level
moisture as well as increasing upper-level instability. Guidance
shows a more stable weather pattern returning to the area early
next week, but showers are forecast to develop over portions of
eastern Puerto Rico and the U.S. Virgin Islands during the
morning. Then local and diurnal effects will induce showers and
isolated thunderstorms across portions of the interior and western
areas of Puerto Rico during the afternoon.

&&

.SHORT TERM...Today through Monday...

Broad surface high pressure across the central Atlantic will
maintain breezy northeast trades across the region through the short
term period. The remnants of a frontal boundary interacting with a
deepening upper level trough over the region will result in
scattered to locally numerous showers across the islands, especially
during the overnight/early Sunday morning hours. With the heaviest
thunderstorms expected mainly across the Caribbean waters and
between the eastern sections of PR and the USVI. Although steering
winds will be strong, sea breeze variations are expected over
southwest PR this afternoon, leading to thunderstorms developing
over and just offshore of southwestern PR. Elsewhere, breezy trades
will carry showers with possible isolated thunderstorms developing
through the late afternoon hours.

For tonight, models continue to suggest better rainfall
accumulations between the eastern half of the island and across the
USVI and surrounding waters. On Sunday and Monday, drier mid to
upper level air is forecast to limit widespread shower coverage
across the region. However, diurnally induced afternoon showers and
isolated thunderstorms are expected to develop over the interior and
across the southwest quadrant of PR.

.LONG TERM...Tuesday through Sunday...

A TUTT low is progged to remain in the central Atlantic well
north of Puerto Rico during the long term period, as a low and
mid-level ridge builds in from the west. Low-level moisture is
forecast to be near climatology, but showers are forecast to
develop across the eastern areas of Puerto Rico and the U.S.
Virgin Islands during the morning hours. Then local and diurnal
effects will induce showers over portions of the interior and
western areas of Puerto Rico during the afternoon. Guidance shows
the TUTT low slowly phasing out by Friday with weak ridging aloft
building overhead. At the Surface east to northeast winds of 10 to
15 mph will prevail through next Sunday.

&&

.AVIATION...Mainly VFR conds expected through at least 15z across
all the terminals. Then, shra/tsra associated to a frontal boundary
over the Atlantic waters under a breezy northeast wind flow could
move at times across the USVI/eastern PR terminals through the
second half of the fcst period. Tempo MVFR cigs and lightning
strikes possible with this activity. Low level winds will continue
from the northeast btw 15-25 kts.


&&

.MARINE...Seas will range from 5 to 7 feet across all the seas
and local waters except for the coastal waters of Southern Puerto
Rico today. There is a small craft advisory for all the
aforementioned areas except for the coastal waters of Southern
Puerto Rico through Sunday afternoon. A high risk of rip currents
for the northern beaches of Puerto Rico, and all the beaches of
Culebra as well as the U.S. Virgin Islands. Winds will be out of
the east to northeast at 10 to 20 knots with higher gusts
possible.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 85 76 / 60 70 30 50
STT 85 76 84 77 / 70 70 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
402 AM AST Sun Nov 4 2018

.SYNOPSIS...Unstable conditions are expected to continue through
mid morning today due to the proximity of a deep layer trough. In
contrast, fair weather conditions are likely Sunday into early
next week as the trough relocates itself northeast of the forecast
area.


&&

.SHORT TERM...Today through Tuesday...

Currently showers and thunderstorms are moving over portions of
eastern Puerto Rico this activity will continue to move to the west
across other areas of the Island this morning. Due to their fast
forward speed rainfall accumulations have been light but if these
showers and thunderstorms keep developing and moving over the same
areas this morning urban and small stream flooding is possible.
developing across the eastern Puerto Yesterday a mid to upper-level
trough with an area of low pressure centered in the northeastern
Caribbean caused unstable weather conditions across Puerto Rico and
the U.S. Virgin Islands. This area of low pressure will move away
from the area later today as a drier airmass filters in aloft.
Therefore, weather conditions are forecast to improve, as a result
of decreasing instability and diminishing moisture over Puerto Rico
and the U.S. Virgin Islands. Additionally, the recent guidance
suggests that mid to upper level clouds will remain over the region
today which will limit shower and thunderstorm development. However,
local and diurnal effects will induce scattered showers and isolated
thunderstorms over portions of the interior and western Puerto Rico
this afternoon.

Monday through Tuesday, drier air will continue to limit shower
development early next week with precipitable water values progged
to fall within the 25th percentile of climatology. At the surface, a
strong ridge of high pressure is forecast to prevail through the
short-term period with east to northeast winds of 10 to 15 mph. One
caveat that could cause the short-term forecast to be adjusted, is
if the current guidance is underestimating the drying of the mid to
upper level of the atmosphere today through the rest of the short-
term period.

.LONG TERM...Wednesday through Monday

The TUTT low will be positioned to the NE of the local region
through most of this period,therefore maintaining Puerto Rico and
the US Virgin Islands under the non favorable area for shower and
thunderstorms development until at least through Thursday. On
Friday the TUTT low is forecast to move north of the Hispaniola
generating a more favorable environment for shower and
thunderstorms development through the incoming weekend.



is progged to remain in the central Atlantic well north of
Puerto Rico during the long term period, as a low and mid- level
ridge builds in from the west. Low-level moisture is forecast to
be near climatology, but showers are forecast to develop across
the eastern areas of Puerto Rico and the U.S. Virgin Islands
during the morning hours. Then local and diurnal effects will
induce showers over portions of the interior and western areas of
Puerto Rico during the afternoon. Guidance shows the TUTT low
slowly phasing out by Friday with weak ridging aloft building
overhead. At the Surface east to northeast winds of 10 to 15 mph
will prevail through next Sunday.


&&

.AVIATION....AVIATION...MVRF/VFR conds are currently prevailing
across the local terminal sites. MVRF conds are occurring due to
SHRA/Isold TSRA moving over the local terminals this morning.
SHRA/TSRA will continue through the morning hours, but should
start diminishing by 04/12Z. SHRA/VCSH will develop across
terminals TJMZ and TJBQ by 04/17Z before dissipating by 04/22Z.
Sfc winds out of the east to northeast at 10 to 20 kts with higher
gusts within SHRA/TSRA.

&&

.MARINE...Mariners can expect dangerous conditions as strong
thunderstorms will continue to move across local waters,
generating strong gusty winds,cloud to water lightning and low
visibilities. Today boaters should expect seas up to 8 feet
mainly across the Atlantic waters and Caribbean passages.
Therefore, small craft advisories are in effect through the rest
of the weekend. A high rip current risk is in effect for the
northern beaches of the islands.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 75 86 76 / 40 30 30 40
STT 86 77 87 77 / 30 30 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
407 AM AST Mon Nov 5 2018

.SYNOPSIS...A mid to upper level trough/Tutt and good low level
moisture convergence will continue to generate moist and unstable
environment across the region through at least late this morning.
This will be followed by a gradual improvement and erosion of low
level moisture as the Tutt and associated Low fills and slowly
lift northeast of the region. However, still expect sufficient
moisture availability for locally and diurnally induced convection
each day, as well as the more typical passing early morning
showers over the coastal waters and along the north and east
coastal sections of the islands.

&&

.SHORT TERM...Today through Wednesday...

An upper level trough will remain in the central Atlantic to the
northeast of Puerto Rico through Wednesday, this trough will
support limited upper-level instability over the region today. A
weak tropical wave currently near Hispaniola has left residual
moisture across the southern Caribbean waters this morning. The
aforementioned upper level trough combined with the rich low-level
moisture will help support showers and isolated thunderstorms this
morning across the Anegada Passage and the Leeward Islands. Then
later today the moisture is forecast to pool over portions of the
interior and western areas of Puerto Rico, which will aid in shower
and thunderstorm development. Analysis of the 700mb GFS shows
another surge of moisture moving over the Leeward Island this
moisture is from a weak tropical wave that will also remain south of
the local islands. Model guidance decreases precipitable water
values across the area on Tuesday due to drier air working in aloft
and decreasing low-level moisture. However, local and diurnal
effects, as well as, sea breeze convergence will induce showers and
thunderstorms mainly over the interior and western areas of Puerto
Rico through Wednesday.

.LONG TERM...Thursday through Monday

The GFS model now has a different resolution from previous runs
for the period between Thursday and Monday. Previous runs showed
the TUTT low moving slowly west through the week positioning the
local area over the active and more favorable conditions for
shower and thunderstorm development. This resolution is not
suggested by the GFS anymore as a frontal boundary moving from
the Eastern Coast of U.S. toward our local will block the westward
movement of the TUTT. This frontal boundary is not forecast to
reach our local forecast area. Although no significant weather
feature are expected for this period available moisture will
combine with local effects to generate afternoon showers across
the interior and western portions of Puerto Rico each day.

&&

.AVIATION...VRF conds are prevailing across all terminal sites,
however SHRA are over the eastern terminals. VCSH will continue
across the eastern terminals through 05/15Z, then SHRA/VCTS will
develop over terminals TJBQ and TJMZ by 05/16Z which could cause
brief MVRF conds. Sfc winds out of the east to northeast at 10 to
15 kts with higher gusts up to 25 kts.


&&

.MARINE...Hazardous wind driven seas will continue to generate choppy
sea conditions through later today. Local buoy network detected
seas around 7 feet at San Juan and between 4 and 5 feet at Ponce,
Rincon and St John. Winds continue from the east at 15 to 20
knots. Small craft advisories continues in effect across the
Atlantic Waters and the Anegada Passage.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 77 86 77 / 40 40 40 20
STT 86 77 86 77 / 40 40 40 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
435 AM AST Tue Nov 6 2018

.SYNOPSIS...Similar unstable pattern is forecast Though at least
early Wednesday as the region will be under the influence of the
upper level trough, then improving conditions for late Wednesday
as moisture content decreases. Unstable pattern will likely return
Thursday and Friday as an induced surface trough moves across the
eastern Caribbean.


&&

.SHORT TERM...A mid to upper-level trough will remain over the
area, providing decent divergence aloft. This combined with
precipitable water values above 1.8 inches is expected to yield to
another active day of shower and thunderstorm activity. During
the early to mid morning hours, some showers are possible across
portions of eastern PR and the USVI. Then from the late morning
into the afternoon time frame, more significant showers and
thunderstorms are expected to develop across interior and western
PR with additional activity possible across portions of eastern PR
and the USVI. Urban and small stream flooding as well as
mudslides in areas of steep terrain are likely in areas that do
experience heavy rainfall. Activity is expected to diminish over
interior and western PR during the early evening hours, however,
showers may continue to linger over portions of eastern PR and the
USVI through the evening hours.

Convection for Wednesday and Thursday is expected to be less in
coverage as the dynamics aloft weaken due to a weakening of the mid
to upper-level trough. Precipitable water values, however, will
remain above 1.7 inches, therefore, expect local and diurnally
induced convection to develop, mainly over interior and western PR
during the afternoon hours.

.LONG TERM...Friday through Tuesday

The TUTT low is forecast to become weaker as it moves slowly
westward. This feature will maintain a constant influx of
moisture that will help generate showers along the local waters
and eastern Puerto Rico during the overnight and early morning
hours. Moisture will also combine with local effects to generate
afternoon showers and thunderstorms along the Cordillera central
and western Portions of puerto Rico through this period.


&&

.AVIATION...Mainly VRF conds will prevail across all terminals
through 06/15Z. SHRA and TSRA likely to develop, particularly near
the vicinity of TJMZ/TJBQ/TJSJ between 06/16Z and 06/22Z, causing
MVFR to even brief IFR conditions. Additional SHRA possible near the
vicinity of TISX/TIST after 06/15z and leeward island terminals
after 06/13Z. Winds will generally be from the east between 5 and 15
kts, with sea breeze variations developing after 06/14z.


&&

.MARINE...Winds will continue to relax therefore seas will also
continue to subside across the local waters. A small raft advisory
will remain in effect for the off shore atlantic waters as seas
will continue to be at around 7 feet through at least mid morning
today. Mariners should continue to exercise caution across the
rest of the waters as seas are forecast to remain between 4 to 6
feet through at least late this afternoon. Wind driven waves of
around 3 to 5 feet will prevail across the local waters through at
least Saturday. A North North East swell will arrive between
Saturday night and early Sunday morning.




&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 76 86 76 / 50 30 30 30
STT 85 74 87 78 / 40 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
414 AM AST Wed Nov 7 2018

.SYNOPSIS...Mid to upper-level trough will continue to linger
across the forecast area for today, continuing to provide unstable
weather conditions. As the mid to upper-level trough weakens and
lifts northward late in the work week into the weekend, a mid
level ridge will settle over the region, providing for a more
stable weather pattern. This stable weather pattern will continue
through the first part of next week. An induced surface trough
will move over the region by the middle of next week, increasing
the areal coverage of the shower and thunderstorm activity once
again.

&&

.SHORT TERM...Wednesday through Friday...

Radar imagery showed shower activity across the U.S. Virgin Islands
overnight, with some of the activity making its way into Vieques
and Culebra. However, most of the activity was observed over the
Virgin Islands and the local waters. This activity will continue
through the morning hours across eastern Puerto Rico and the U.S.
Virgin Islands while the western sections of Puerto Rico will
observe mostly sunny skies with no shower activity.

A mid to upper level trough inducing a surface trough will combine
with the available tropical moisture to result in another round of
showers and thunderstorms across the interior and western
sections of Puerto Rico late this morning into the afternoon
hours. Also, sea breeze and local topography will aid in the
development of showers and isolated thunderstorms across the San
Juan Metro area and the north central municipalities, where
rainfall accumulations could create urban and small stream
flooding during the afternoon hours. However, the strongest
activity is forecast across the interior and western sections
where accumulations could range between one and two inches with
locally higher amounts.

Model guidance suggests the upper trough/TUTT dominating the
eastern Caribbean through at least early Thursday morning. Then,
this feature is expected to weaken later Thursday and Friday.
Although a mid level ridge will settle over the region limiting
the instability across the region, overnight and early morning
showers are expected across the E-PR/USVI followed by afternoon
convection across interior/western PR each day.

.LONG TERM...Saturday through Wednesday...

A more stable weather pattern is expected by the weekend as the
aformentioned mid-level ridge will settle over the region. An
upper-level low is forecast to dig down from the north late in
the weekend through early next week, however, it appears that it
will remain to our northeast with the region being on the
subsident side. Even though the synoptic pattern by this weekend
into early next week supports a more benign weather pattern,
sufficient low-level moisture will remain in place. Therefore,
during the overnight into the early morning hours, passing trade
wind showers may affect portions of eastern PR and the USVI
followed by the development of locally and diurnally induced
shower and isolated thunderstorm activity over interior and
western portions of PR during the afternoon hours. More unsettled
weather conditions may return to the region by the middle of next
week as an induced surface trough moves across, increasing the
areal coverage of the shower and thunderstorm activity once again.

&&

.AVIATION...VFR conditions are expected most of the time across the
local flying area. However, passing SHRA will move across TIST/TISX
TNCM/TKPK/TJSJ. Some of them will create SCT-BKN lyrs nr FL05-FL090
at times. SHRA/TSRA are forecast across the interior/west PR and in
the VCTY of TJSJ between 07/16-23z. Brief MVFR would be possible at
TJMZ/TJPS due to SHRA/Isold TSRA. Surface winds will continue calm
to light and vrb increasing at 10 to 15 kt with higher gusts in/near
SHRA/TSRA aft 07/13z.

&&

.MARINE...Choppy seas up to 6 feet are expected to continue
across the offshore Atlantic waters through Thursday. Therefore,
small craft operators are urged to exercise caution. Across the
rest of the regional waters, seas between 3 to 5 feet are expected
to prevail. A moderate risk of rip currents is expected across
the north facing beaches of Puerto Rico, Culebra, and Saint Thomas
and across the north and east facing beaches of Vieques and Saint
Croix.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 88 76 / 30 40 40 50
STT 86 77 87 77 / 40 40 40 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
413 AM AST Thu Nov 8 2018

.SYNOPSIS...A more stable weather pattern will gradually build
across the region through the weekend as the mid to upper-level
trough lifts northward and weakens and a mid level ridge replaces
it. Enough low-level moisture, however, will remain in place to
result in trade wind showers across windward areas during the
overnight and morning hours followed by afternoon convection
across interior and western PR. A wetter weather pattern is
possible by the middle to latter half of next week as a trough
pattern sets up over the region to result in an increase in shower
and thunderstorm activity.

&&

.SHORT TERM...Today through Saturday...

An induced surface trough and plenty of tropical moisture brought
showers and isolated thunderstorms across the northern U.S. Virgin
Islands and the east and north sections of Puerto Rico overnight.
Some of these showers produced periods of moderate to heavy showers
across these areas. Due to unstable weather conditions this activity
will continue through the morning hours while the western
sections of Puerto Rico will observe mostly sunny skies with no
shower activity. As the surface perturbation moves across the
region, local and diurnal effects will aid in the development of
another round of showers and thunderstorms across the interior and
northwest quadrant of Puerto Rico during the afternoon hours.
Periods of heavy showers and isolated thunderstorms can also be
expected downwind from El Yunque into the San Juan Metro area and
north-central PR.

The TUTT will weaken as it moves slowly northeastward, allowing
the intrusion of a drier and more stable air mass at mid to upper
levels by late this afternoon into the upcoming weekend.
Although upper-level dynamics will diminish, at low-levels plenty
of tropical moisture will aid in the development of overnight and
early morning showers across E-PR/USVI followed by afternoon
convection across interior/western PR each day. It is important to
point out that the coverage of this activity will be less than in
previous days.


.LONG TERM...Sunday through Thursday...

Mid-level ridge will influence the weather pattern through at
least Tuesday. This will serve to limit the potential for
organized and widespread deep convection across the region. Low-
level moisture, however, will be sufficient to the point that the
threat of showers will continue to exist. Therefore, expect brief
trade wind showers across portions of eastern PR and the USVI
during the overnight and early morning hours followed by the
development of afternoon shower and isolated thunderstorm activity
across interior and western portions of Puerto Rico due to local
and diurnal effects.

Model guidance continues to depict a wetter weather pattern to
envelop the forecast area by the middle to latter half of next week
as a trough pattern settles in over the area. This will serve to
increase the instability aloft as well as moisture pooling due to
a moist southeasterly flow. Therefore, an increase in shower and
thunderstorm activity can be expected across the region if the
current model trend continues to hold.

&&

.AVIATION...VFR conds is expected most of the time. However, passing
SHRA/+SHRA could affect NE-PR/USVI/Leeward islands terminals to
create SCT-BKN lyrs nr FL025-FL090 at times through at least 08/15z.
Then SHRA/TSRA will develop across the interior/NW-PR and in the
VCTY of TJSJ between 08/16-23z. TEMPOs could be required later this
morning as MVFR conds at TJBQ/TJMZ due to SHRA/TSRA are likely. Calm
to light-VRB winds will continue through at least 08/13z, increasing
at 10-15 kt from E-ESE with sea breeze variations.

&&

.MARINE...Seas up to 6 feet will continue across the northern
portions of the offshore Atlantic waters through this morning.
Seas of 3 to 5 feet are expected across the rest of the regional
waters. Seas are expected to increase above 7 feet across the
offshore Atlantic waters by early next week as winds increase to
near 20 knots. A moderate risk of rip currents continues for the
north facing beaches of Puerto Rico, Culebra and Saint Thomas and
across the north and east facing beaches of Vieques and Saint
Croix.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 76 88 77 / 40 40 40 40
STT 87 78 86 77 / 40 60 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
508 AM AST Fri Nov 9 2018

.SYNOPSIS...
An upper level trough and a surface perturbation combined with
plenty of tropical moisture will keep high the potential for
showers and thunderstorm development across the forecast area
today. Conditions will gradually improve through the weekend as
the upper level feature weakens and a mid-level ridge builds from
the west. Scattered showers will continue to move across the
regional waters, the U.S. Virgin Islands and eastern Puerto Rico
throughout the morning hours. Unsettled weather conditions will
return by midweek next week.

&&

.SHORT TERM...Today through Sunday...
Surface high pressure across the north central Atlantic, along with
a broad induced low level trough spread across the eastern Caribbean
and a tropical wave moving westward across the forecast area will
maintain a moist advective pattern today through most of the
upcoming weekend. This along with the proximity of the mid to upper
level trough/TUTT will continue to provide good ventilation and
divergence aloft resulting in a very unstable environment at least
through Saturday. Although the TUTT will continue to fill while
slowly lifting northward through the weekend, expect the unstable
conditions to persist for at least the next 24-48 hours. This will
be followed by a gradual improvement on Sunday.

For today and Saturday...early morning showers and isolated
thunderstorms will continue to affect the coastal waters and east
sections of the islands, followed by shower and thunderstorm
development mainly over the central and western half of the islands,
including the San Juan metro area during the afternoon hours. Some
of the rains will continue to be heavy at times and will lead to
urban and small stream flooding over Puerto Rico, as well as over
parts of the U.S. Virgin islands where soil remain very saturated.
Mudslides will continue to be a problem in area of steep terrain.

By Sunday...a more stable air mass is so far forecast to filter
in and spread across the region as the TUTT lifts northwards and
winds become more east northeast resulting in gradual erosion of
the low level moisture. Still however expect early morning passing
showers along the east coastal sections of the islands followed
by locally and diurnally induced afternoon convection over parts
of the central and southwest sections of Puerto Rico. Lesser
shower activity is also forecast for the U.S. Virgin Island on
Sunday.

.LONG TERM...Monday through Friday...

Mid-level ridge will move from the west into the northeast
Caribbean by early next week. This will limit the vertical
development and will allow the intrusion of a drier and more
stable air mass at mid to upper levels. However, model guidance
continues to suggest sufficient low-level moisture to aid in the
development of showers Monday and Tuesday. Therefore, expect
trade wind showers across the local waters, the U.S. Virgin
Islands and the windward sections of Puerto Rico during the
overnight and early morning hours followed by the development of
afternoon showers and possibly isolated thunderstorms across
interior and western portions of Puerto Rico due to local and
diurnal effects.

Model guidances agrees that a wetter and unstable pattern will
set-up by mid-week into the end of the work-week as a trough
pattern settles in over the area. If models are correct, an
increase in showers and thunderstorms could be expected across the
region.

&&

.AVIATION...SHRA/TSRA will continue to affect flying area btw PR
and the Leeward Islands with brief MVFR en route btw islands. Mtn
obsc 09/06Z-09/12z ovr E PR due to low CIG/SHRA. SCT-BKN lyrs nr
FL025...FL050...FL090 til 09/14z. Sfc winds east less than 10
knots, bcmg 10-15 kt by 09/14z. SHRA/isold TSRA ovr interior PR
and northwest of El Yunque fm 09/16Z-09/22z, also spreading west
vcty TJBQ/TJMZ with MVFR conds due to CIGS/VSBY.

&&

.MARINE...
Seas will continue at 4 to 6 feet across the Atlantic Offshore
waters, therefore small craft operators are urged to exercise
caution. The rest of the local waters will observe seas between 2
and 5 feet. The winds will continue from the east to east-
southeast at 10 to 15 knots. This trend will continue through at
least Monday or Tuesday. Then, winds and seas are forecast to
increase by the middle to latter half of the next week as a
surface high pressure builds across the Atlantic Waters.

For the beach goers, the risk of rip currents will continue for
the northern and some eastern beaches of all the local islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 88 77 / 60 40 50 50
STT 87 77 86 77 / 60 60 50 50

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
514 AM AST Sat Nov 10 2018


.SYNOPSIS...
Although conditions will continue to gradually improve through at
least Tuesday, a surface trough and plenty of tropical moisture
will continue to promote showers and thunderstorms across the
islands. Showers will affect the local waters, the U.S. Virgin
Islands and east Puerto Rico through the morning hours. Then, this
activity is expected to develop across the Cordillera Central and
the southwest quadrant of Puerto Rico as well as near the San
Juan Metropolitan area during the afternoon. Unsettled weather
conditions will return by midweek next week.

&&

SHORT TERM...Today through Monday... Surface high pressure across
the north central Atlantic, and a broad induced low level trough
spread across the eastern Caribbean will help maintain a moist east
to southeast advective pattern across the region today. The trough
is to expected to weaken across the region and sink further
southwards by Sunday and Monday as the Atlantic High pressure ridge
builds north of the region and induces a more east to northeast wind
flow. Mid to upper level trough will continue to weaken and slowly
lift north northeast of the region through Monday as high pressure
ridge is forecast to build west and north of the forecast
area.

Now through Sunday...Showers and isolated thunderstorms will
continue to develop across the coastal waters and brush mainly the
north and east coastal sections of the islands into the early
morning hours. Under a prevailing east to southeast wind flow today
expected afternoon convection to develop over the interior then
steer westward and southwest across the surrounding municipalities.
Afternoon showers and isolated thunderstorms will also remain
possible over the east interior and around the San Juan metro. Some
of the associated rains will be heavy at times and may again lead to
urban and small stream flooding over Puerto Rico. Afternoon shower
development with a slight chance of an afternoon thunderstorm is
also forecast for the U.S. Virgin Islands, but the activity should
be focused mainly on the west end of the islands or just off the
west coastal areas. Mudslides will continue to be a problem in
areas of steep terrain as well as minor flooding and ponding of
water on roadways and in poor drainage areas.

By Monday...a more stable and even drier air mass is so far forecast
to filter as winds become more northeasterly and moisture
convergence is expected to decrease and erode as the high pressure
ridge builds and spreads across the forecast area. Still however
expect the typical early morning passing showers along the east
coastal sections of the islands followed by locally and diurnally
induced afternoon convection over parts of the central and southwest
sections of Puerto Rico with lesser daytime shower activity so far
forecast for the U.S. Virgin Islands.

.LONG TERM...Tuesday through Saturday

Model guidance continues to suggest a more dry and stable air
mass at mid-upper levels to result in a similar weather pattern
than Monday. Although a gradual erosion of the low level
moisture is expected, a high pressure across the Atlantic Ocean
will promote a northeast wind flow which will bring trade wind
showers across the local waters, the U.S. Virgin Islands and the
windward sections of PR during the night and morning hours. Then,
the available moisture combined with local and diurnal effects
will induce afternoon convection across the interior and southwest
quadrant of Puerto Rico. Lesser shower activity is also forecast
for the U.S. Virgin Island.

A tropical wave located several hundred miles east of the Lesser
Antilles is expected to move close to the islands by late Tuesday
night or early Wednesday morning. There is some discrepancy
between GFS and ECMWF about the evolution of this system. The
local weather will by tied to the evolution of this tropical wave.
However, model guidance continues to depict a wetter weather
pattern to envelop the forecast area by the middle to latter half
of next week as a trough pattern settles in over the area. This
will serve to increase the instability aloft as well as moisture
pooling due to a moist southeasterly flow. A mid to upper level
ridge is then forecast to build across the region by Saturday,
limiting the formation of showers and thunderstorms if the current
model trend continues to hold.

&&

.AVIATION...
Prevailing VFR...SCT-BKN lyrs nr FL025.FL050...FL080 ovr
regional waters with SCT SHRA/isld TSRA. Mostly SKC ovr land areas
til 10/14z except for Mtn top obscr ovr E PR in SHRA/Low clds. Brief
MVFR due to low CIG/SHRA en route btw islands and incr convection
near the northern Leeward islands til 10/12z. Sfc winds lgt/vrb to
calm, bcmg 10-15 kt aft10/14z. SHRA/isold TSRA psbl ovr interior PR
and northwest of El Yunque fm 10/16Z-09/22z, also spreading ovr west
interior VCTY TJBQ/TJMZ with MVFR conds due to low CIGS/VSBY.

&&

.MARINE...
Small craft operators should continue to exercise caution across
the Anegada passage and the offshore Atlantic waters due to seas
up to 6 feet. Elsewhere, seas of 2-5 feet will prevail through
the end of the week. Winds and seas are forecast to increase again
early next week with seas reaching 7 feet across the offshore
waters by midweek next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 88 78 / 50 50 50 50
STT 86 77 87 77 / 50 60 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
510 AM AST Sun Nov 11 2018

.SYNOPSIS...
A surface high pressure across the north central Atlantic, and a
broad induced surface trough across the eastern Caribbean will
maintain a moist northeasterly advective pattern across the
islands through at least Monday. The upper-level trough is
forecast to drift over the Lesser Antilles through at least late
Monday night.

An active tropical wave now located several hundred miles east of
the Lesser Antilles is being watched by the National Hurricane
Center. Although significant development of this system is not
expected the next couple of days, conditions are forecast to
become more favorable by late Tuesday. Regardless of the evolution
of this system, an increase on moisture is forecast as the
tropical feature moves north of the U.S. Virgin Islands and Puerto
Rico by mid-week.

&&

.Short Term...Today through Tuesday...
Surface high pressure across the north central Atlantic and
persistent broad low level trough across the eastern Caribbean, will
maintain a moist east to northeast advective pattern at least
through today. The trough is to expected to weaken across the region
and sink further southwards later today through Monday as the
Atlantic High pressure ridge builds north of the region. This
feature along with a developing tropical wave will induce a
moderate northeast wind flow through Tuesday. Mid to upper level
trough will continue to weaken and slowly lift northeast through
Monday as high pressure ridge aloft is forecast to build just west
and north of the forecast area.

Low level moisture continues in abundance and showers over the local
Atlantic and Caribbean waters will persist through the early morning
hours. Showers and cloudiness will taper off and diminish by mid
morning, but is expected to return to parts of the interior and
southwest Puerto Rico during the afternoon hours. This will again
result in afternoon thunderstorm development in some areas with
periods of heavy rains. Urban and small stream flooding should be
mainly across parts of the interior and west sections of PR during
the afternoon. Winds will be mainly from the east northeast between
10 to 15 mph with some higher gusts near thunderstorms and along the
north coastal areas. Shower activity should also taper off in and
around the USVI by mid morning with lesser shower activity expected
during the afternoon.

Monday and Tuesday...a more stable and somewhat drier air mass is so
far forecast to filter in at least through early Tuesday, as winds
become more northeasterly and moisture advection is expected to
diminish and erode as the high pressure ridge builds just north of
the area. Still however expect the typical early morning passing
showers along the north and east coastal sections of the islands
followed by locally and diurnally induced afternoon convection over
parts of the central and southwest sections of Puerto Rico. Isolated
to scattered shower activity is so far forecast for the U.S. Virgin
Islands. By late Tuesday however, weather conditions across the
region are expected to rapidly deteriorate due to an approaching
active tropical wave.

.LONG TERM....Wednesday through Sunday...
An active tropical wave located several hundred miles east of the
Lesser Antilles is expected to move north of the islands by late
Tuesday night or early Wednesday morning. There is some
discrepancy between GFS and ECMWF about the evolution of this
system. However, based on the most recent NHC-guidance this
feature has a 50 percent chance of development in the next 5 days.
The local weather will by tied to the evolution of this tropical
wave. But, regardless of the evolution of this system, model
guidance continues to depict a wetter weather pattern to envelop
the forecast area by mid-week as a trough pattern aloft settles
in over the area. This will provide good upper level dynamics as
well as moisture pooling across the eastern-Greater Antilles due
to a moist southeasterly wind flow.

A mid to upper level ridge is then forecast to build across the
region around Saturday, to limit the formation of showers and
thunderstorms if the current model trend continues to hold.

&&

.AVIATION...
Periods of MVFR fcst btw PR and the Leeward Islands til arnd 11/14Z
due to low cig with SHRA/ Isold TSRA....with SHRA/TSRA to also
persist vcty of USVI til 11/12z. Expect MVFR and mtn obscurations to
dvlp in PR aft 11/10Z with low CIG/SHRA. Winds ENE-E less than 10
knots except nr SHRA/TSRA...bcmg 10-20 kt aft 11/14Z. Max winds W 25-
30 kts btwn FL350-480 bcmg WNW by 11/12Z. Brief MVFR mainly ovr
central mtn range and vcty TJBQ/TJMZ fm 11/16z-11/22z due to
SHRA/TSRA.

&&

.MARINE...
Mariner should exercise caution across the Atlantic Waters and
Caribbean Passages due to seas between 4 and 6 feet through at
least tomorrow Monday. Elsewhere seas will range between 3 and 5
feet.

Winds and seas are forecast to reach 7 in the local outer
Atlantic waters by Monday night and could be seen as early as
Monday afternoon in the far northeastern corner of the forecast
area. In addition, marine models suggest seas will increase
between 6 and to 8 feet with occasional seas up to 10 feet across
these waters by Tuesday. Then hazardous seas are expected to
spread into the coastal waters by Tuesday.

For the beach goers, the risk of rip currents is moderate for
some of the north, southeast and east beaches of the islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 78 87 79 / 50 50 40 50
STT 87 77 88 78 / 50 50 40 50