Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
547 AM AST Sat Dec 10 2016

.SYNOPSIS...Ridge pattern at mid to upper levels will dominate
the local region over the next several days. Conditions aloft will
remain fairly dry and stable...limiting the chances of thunderstorms
across the local area. At low levels...moisture embedded in the
trade winds will continue to reach the islands from time to time.
In general...trade wind pattern will prevail across Puerto Rico
and the U.S. Virgin Islands most of next week.

&&

.DISCUSSION...Satellite and radar imagery showed scattered
showers moving westward across the surrounding waters of Puerto
Rico and the U.S. Virgin Islands. A few of these showers moved
inland across portions of eastern Puerto Rico. However...minimal
rainfall accumulations were observed across the local islands with
this activity.

Today and tonight...Passing showers may reach portions of the
U.S. Virgin Islands as well as the eastern Puerto Rico this
morning. Then...some convection will develop over western Puerto
Rico this afternoon.

Next week...Trade wind pattern will hold most of the week. Strong
high pressure will build over the Western Atlantic...increasing
the trade winds across the region. Brisk easterlies will favor
the generation of streamers downwind of the small islands. Some
showers will form over western PR...however light rainfall amounts
are expected as mid levels remain fairly dry most of the week.

&&

.AVIATION...Mainly VFR conditions expected across all terminals
morning and early afternoon. Winds expected to increasing to 10 to
15 knots from the ENE with sea breeze variations near JPS, TJMZ
and TJBQ after 11/17Z. VCSH are expected near TJMZ and TJBQ after
11/18Z with potential MVFR conditions until at least 11/23Z.
Conditions are expected to return to VFR across all terminals
after 11/23Z.

&&

.MARINE...Increasing winds and seas are forecast from Sunday into
early next week as a strong high pressure builds north of the local
islands. Seas will build from 3-5 feet to 5-7 feet by Sunday.
Small Craft Advisories may issue later today or tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 86 76 / 30 30 20 10
STT 86 77 87 75 / 30 40 20 10

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
202 PM AST Sat Dec 10 2016

.SYNOPSIS...Ridge pattern at mid to upper levels will dominate
the local region over the next several days. Conditions aloft will
remain fairly dry and stable...limiting the chances of thunderstorms
across the local area. At low levels...moisture embedded in the
trade winds will continue to reach the islands from time to time.
In general...trade wind pattern will prevail across Puerto Rico
and the U.S. Virgin Islands most of next week.

&&

.DISCUSSION...Only light passing showers were observed across the
local area this afternoon. Only some fast moving showers were
observed across the local islands. Afternoon showers across the
mountainous areas of PR are possible but the highest chance of
showers are expected to be across the western interior and western
sections of PR. Even then, the accumulations are expected to
produce generally minor ponding of water on roadways and poor
drainage areas. Some showers may stream off the USVI but no major
accumulations are expected over the islands.

High pressure across the Atlantic will continue to dominate the
local region next several days. Moisture embedded in the trade
winds will continue to reach the islands from time to time. In
general...trade wind pattern will prevail across Puerto Rico and
the U.S. Virgin Islands most of next week. Overall, no significant
weather events are forecast to affect the region in the long
term.

&&

.AVIATION...VFR conds expected across the local terminals with a
prevailing easterly wind at about 10kt with sea breeze variations.
VCSH across TJPS and TJMZ after 10/18Z. Winds to decrease after
11/13Z becoming light and variable in most of the terminals.

&&

.MARINE...Seas up to 6 feet and winds up to 20 knots are expected
to prevail across the local waters through Sunday morning...increasing
up to 8 feet by Sunday afternoon. As a result...A small craft
advisory will be in effect from Sunday afternoon across most
coastal waters.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 86 76 84 / 30 20 10 20
STT 77 87 75 86 / 40 20 10 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
549 AM AST Sun Dec 11 2016

.SYNOPSIS...Mid to upper level ridge will hold over the next
several days. The fairly dry and stable conditions aloft will
limit the vertical development of the showers across the local
area. At low levels...strong surface high pressure north of the
islands will continue to push patches of moisture across the local
islands from time to time. In general...a typical trade wind
pattern will prevail across Puerto Rico and the U.S. Virgin
Islands most of the week.

&&

.DISCUSSION...A brisk easterly winds is enhancing the moisture
convergence across the Northeast Caribbean. This result in a band
of showers moving across Puerto Rico and the U.S. Virgin Islands
this morning. Although...scattered to numerous showers moved
across the forecast area...land breezes have kept most of the
showers over the regional waters. Therefore...no significant
rainfall accumulations were observed across the local islands
since midnight.

Today and tonight...Breezy conditions will continue across the
local islands with winds increasing around 20 MPH later today.
A drier air mass over the Leeward Islands will spread over the
U.S. Virgin Islands and Puerto Rico by mid-morning...limiting the
shower coverage across the islands the rest of the day. Therefore...
expect a fair weather pattern through late tonight.

Work Week...Another wind surge is forecast early in the week. This
will lead to moisture converge across the region especially Monday
and Tuesday. Therefore...the coverage of the trade winds showers
will increase across the local islands especially at night and
early in the morning. Similar pattern will prevail from Wednesday
into Friday...with passing showers affecting the islands at times.
In summary...a generally fair weather pattern is expected most of
the week...except for brief interruptions as trade wind showers
pass by.

&&

.AVIATION...Mainly VFR conditions expected across all terminals
during the next 24 hours. Trade winds showers across the waters
early in the fcst period but mainly resulting in brief periods of
VCSH/-RA, if any. Isld-Sct afternoon SHRA possible along the
western interior impacting the flying area of TJMZ. Forecast
soundings have low level Easterlies winds at 15 to 25 kts.

&&

.MARINE...Winds and seas are forecast to increase through Monday
as a strong high pressure builds north of the local islands. Seas
will peak at 6-8 feet especially across the offshore waters
between Monday and Tuesday. As a result...Small Craft Advisories
remain in effect for most of the waters...except the coastal
waters of Western Puerto Rico. Marine conditions will gradually
improve the second part of the week.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 77 81 76 / 30 20 20 30
STT 81 78 81 77 / 20 30 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
127 PM AST Sun Dec 11 2016

.SYNOPSIS...Mid to upper level ridge will remain as the main
weather feature across the region until the middle of the week.
This feature will continue to inhibit the development of
significant shower activity across the region. Patches of moisture
embedded in the trades winds will continue to produce passing
showers across the local islands for the next several days.

&&

.DISCUSSION...Doppler weather radar detected isolated to
scattered showers across eastern sections of Puerto Rico as well
as across Vieques, Culebra and the U.S. Virgin Islands early this
morning. However by mid-morning this activity dissipated leaving
only partly cloudy skies with limited shower activity as a drier
air mass moved from the leeward islands over the U.S. Virgin
Islands and eastern Puerto Rico. This generally dry air mass is
expected to encompass the rest of the region this afternoon.

A strong surface high pressure across the western Atlantic will
continue to induce breezy conditions across the local islands and
coastal waters for the next several days with winds expected to
increase at around 20 MPH this afternoon and tonight. Areas of low
level moisture embedded in this trade wind flow will produce brief
periods of passing showers across the U.S. Virgin Islands,
Vieques, Culebra an eastern Puerto Rico overnight and early in the
morning, but in general fair weather pattern is expected most of
the week.

&&

.AVIATION...Mainly VFR conditions expected across the local flying
area during the next 24 hours. Trade winds showers will affect the
Leewards, USVI and TJSJ taf sites overnight and early Monday
morning but mainly resulting in brief periods of VCSH/-RA. Isld-
Sct afternoon SHRA possible along the western interior impacting
the flying area of TJMZ.

&&

.MARINE...Winds and seas are forecast to increase through Monday
as a strong high pressure builds north of the local islands. Seas
will peak at 6-8 feet especially across the offshore waters
between Monday and Tuesday. As a result...Small Craft Advisories
remain in effect for most of the waters...except the coastal
waters of Western Puerto Rico. Marine conditions will gradually
improve the second part of the week.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 81 76 86 / 20 20 30 30
STT 78 81 77 86 / 30 30 40 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
519 AM AST Mon Dec 12 2016

.SYNOPSIS...Ridge aloft will continue to dominate the local area through
the end of the work week. Strong surface high pressure over the
Western Atlantic will continue to move into the Central Atlantic
promoting fresh to locally strong easterly winds for the next
several days. A frontal boundary is forecast to reach the local
area by late Friday into Saturday.

&&

.DISCUSSION...Breezy conditions prevailed across the forecast area
during the overnight hours, specially over the waters and coastal
areas of the islands. Showers embedded on the trades were mainly
observed across the Caribbean waters with a few of them moving
from time to time across the USVI. Gusty winds up to 30 mph were
reported with these showers at the Henry E. Rohlsen airport in St.
Croix. Rainfall was generally less than a quarter of an inch of
rain over land areas.

The ridge aloft and surface high pressure will promote a trade
wind shower pattern across the USVI and coastal areas of eastern
and northern PR through the rest of the week. Limited afternoon
shower development is expected each day over the islands. Breezy
conditions are expected through at least Tuesday with sustained
easterly winds between 15 to 25 mph. On Friday-Saturday, an
increase in cloudiness and shower activity is forecast as frontal
boundary reach the Atlantic waters and the upper ridge relaxes as
short wave trof press against it.

&&

.AVIATION...VFR conditions expected across all terminals during the
forecast period. Passing SHRA will move across the flying area
today. This may result in brief MVFR cigs across the Leeward and
USVI terminals the rest of morning while mountain obscurations are
possible along the Cordillera Central in the afternoon. Low level
winds of 15 to 25 kts can be expected below FL200.

&&

.MARINE...Fresh to strong trade winds will continue to create
hazardous seas across the regional waters through at least
midweek. Small craft advisories are in effect for all waters
except the western coastal waters of PR due to seas up to 8 feet.
A high rip current risk is in effect for the Atlantic and
southeastern beaches of PR, Culebra, Vieques and St. Croix.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 78 84 76 / 30 40 40 30
STT 85 78 85 77 / 30 40 40 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
154 PM AST Mon Dec 12 2016

.SYNOPSIS...Ridge aloft will continue to dominate the local area through
the end of the work week. Strong surface high pressure over the
Western Atlantic will continue to move into the Central Atlantic
promoting fresh to locally strong easterly winds for the next
several days. A frontal boundary is forecast to reach the local
area by late Friday into Saturday.

&&

.DISCUSSION...Patches of low level moisture embedded in the trade
winds produced showers across the local area this morning and
early this afternoon. These patches of low level moisture will
continue to affect the local islands from time to time. Local area
will remain under the influence of an upper level ridge and a
surface high pressure system over the Western Atlantic. Therefore,
little changes in this weather pattern is expected.

For late Friday into Saturday, A frontal boundary is forecast to reach
the local area which will increase the cloudiness and shower
activity across the region. However at this time, no significant
rainfall accumulations are expected to affect the region with this
system.

&&

.AVIATION...VFR conds expected to prevail at all TAF sites through
the forecast period with brief MVFR possible in passing SHRA.
Easterly winds at 15-25 knots through 12/22z becoming 10-12 knots
overnight.

&&

.MARINE...Fresh to strong trade winds will continue to generate
hazardous seas through midweek. Small craft advisories are in
effect for all waters except the western coastal waters with a
high rip current risk in effect for the Atlantic and southeastern
beaches of PR, Culebra, Vieques and St. Croix.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 84 76 85 / 40 40 30 30
STT 78 85 77 84 / 40 40 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
541 AM AST Tue Dec 13 2016

.SYNOPSIS...Mid to upper ridge across the Caribbean basin will
continue to dominate the local area through the end of the work
week. Ridge will slowly erode as polar trough press against it by
the end of the work week. Broad surface high pressure over the
the Central Atlantic will continue to promote fresh to locally
strong easterly winds through at least Wednesday. Prefrontal
boundary is forecast to reach the local area late Friday into
Saturday. Northeasterly trades expected to increase once again in
the weekend as another surface high enters the Western Atlantic.

&&

.DISCUSSION...Trade wind showers continued across the forecast
area through the overnight hours. The highest rainfall amounts
were observed at St. Thomas with just above a quarter of an inch
reported at the Cyril E. King airport. Some of these showers
affected briefly areas of eastern PR including Culebra. Similar
conditions are expected for the rest of the day. Breezy trades
carrying quick passing showers across the USVI and mainland PR.
Shallow afternoon shower development is possible across portions
of western PR, but rainfall no significant rainfall amounts are
forecast at the moment. This weather pattern should continue for
the next few days, with the driest day expected on Thursday.

By Friday into the weekend, cloudiness and shower activity is
forecast to increase across the local area as polar trough across
the Western Atlantic presses against the upper ridge and
prefrontal shearline moves north of the area. Meanwhile another
strong surface high pressure will enter the Western Atlantic
promoting fresh to locally strong northeasterly trade winds.


&&

.AVIATION...VFR conditions expected across most of the TAF sites
during the forecast period. SCT SHRA will move west across the
flying area today. Some of these SHRA will lead to brief MVFR conds
as they pass by. Mountain obscurations are possible along the
Cordillera Central. East winds of 15 to 25 kts will prevail below
FL200.


&&

.MARINE...Hazardous seas will continue across the regional waters
Today. Small craft advisories are in effect due to seas up to 8
feet. Easterly winds around 20 knots are expected across much of
the area. Winds and seas will slowly subside late in the work
week but increase once again during the weekend in response to a
strong surface high pressure entering the Western Atlantic. A
moderate to high risk of rip currents continues Today for most of
the beaches of the islands.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 75 85 75 / 40 20 20 20
STT 85 76 85 75 / 40 20 30 20

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
125 PM AST Tue Dec 13 2016

.SYNOPSIS...A seasonable weather pattern will continue to prevail
across the local islands through the end of the workweek with
showers embedded in the trades at times, particularly across the
USVI and eastern Puerto Rico, as well as a few locally induced
afternoon showers...if any...across west PR. Prefrontal shearline
is forecast to reach the local area late Friday into Saturday.

&&

.DISCUSSION...Variably cloudy skies prevailed across the local
islands with passing scattered showers across the USVI and the
eastern half of PR. Afternoon coastal temperatures ranged from
the mid to upper 80s. Surface winds were mostly from the east
at 15-20 mph with occasional higher gusts.

A mid to upper level ridge will continue to prevail across the
forecast area through Friday. Although trofiness is then expected
at upper levels Friday and into the upcoming weekend, the mid level
ridge will continue to hold through early next week. Migratory
surface highs north of the area will generally promote fresh trade
winds through the period with a prefrontal shearline reaching the
local area late Friday into Saturday. Under this evolving pattern,
expect a seasonable weather pattern with showers embedded in the
trades at times, particularly across the USVI and eastern Puerto
Rico, as well as a few locally induced afternoon showers...if
any...across west PR. The frequency of passing showers may increase
Friday and into the upcoming weekend as low level moisture pools
across the forecast area due to approaching shearline. Low level
moisture will then erode once again Monday through midweek next week
as the upper level trough moves southeast of the local islands
with its associated convergence side over the area.

&&

.AVIATION...VFR conditions expected across most of the TAF sites
during the forecast period. SCT SHRA will continue to move across
the flying area through the forecast area. Some of these SHRA will
lead to brief MVFR conds as they pass by. Mountain obscurations are
possible along the Cordillera Central through 13/22z. Low level
winds will be mainly East at 15 to 20 kts with higher gusts.

&&

.MARINE...A broad surface high pressure north of the local islands
will continue to promote fresh trade winds across the local
waters. This will continue to result in choppy seas through at
least late Wednesday night. Although...winds and seas will subside
by midweek...seas and winds will increase once again during the
upcoming weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 85 75 85 / 20 20 20 20
STT 76 85 75 84 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
510 AM AST Wed Dec 14 2016

.SYNOPSIS...A seasonable weather pattern will continue to
prevail across the local islands through Friday with showers
embedded in the trades at times, particularly across the USVI
and eastern Puerto Rico, as well as a few locally induced
afternoon showers...if any...across west PR. Prefrontal
shearline is forecast to reach the local area late Friday
into Saturday.

&&

.DISCUSSION...Clear to partly cloudy skies prevailed across
the forecast area during the overnight hours. Passing trade
wind showers were noted across the waters between the U.S.
Virgin Islands and eastern Puerto Rico. The doppler radar
estimated around a quarter of an inch of rain with this activity
over portions of Fajardo and Luquillo. Overnight temperatures
across coastal areas ranged from the lower 70s to 80 degrees.
The wind was from the east between 10 and 15 mph.

A mid to upper level ridge will continue to prevail across the
forecast area through Friday. Although some weakening is expected
particularly at upper levels Friday and into the upcoming weekend,
the mid level ridge will continue to hold through early next week.
Migratory surface highs north of the area will generally promote
fresh to locally strong trade winds with a prefrontal shearline
reaching the local area late Friday into Saturday. Under this
evolving pattern, expect a seasonable weather pattern with showers
embedded in the trades at times, particularly across the USVI and
eastern Puerto Rico, as well as a few locally induced afternoon
showers...if any...across west PR.

The frequency of passing showers may increase Friday and into the
upcoming weekend as low level moisture pools across the forecast
area due to approaching shearline. Low level moisture will then
erode early next week as a trough amplifies from the central
Atlantic into the eastern caribbean with the forecast area
remaining under its convergent side. At this time, best moisture
advection as well as favorable upper level dynamics should
remain over the Lesser Antilles Wed-Fri.

&&

.AVIATION...Mainly VFR conditions expected across all terminals
during the next 24 hours. However, trade wind showers could create
brief periods of -RA/VCSH across the Leeward/USVI and eastern PR
terminals through the entire forecast period. Max tops around FL150.
Surface winds mainly East at 15 to 20 kts with higher gusts after
14/13z.

&&

.MARINE...Although winds and seas are subsiding...choppy seas are
still expected across the offshore waters with seas between 6 to 8
feet. Small craft advisories were cancelled for the nearshore
waters since the local buoy network is indicating seas below the
small craft criteria. small craft advisories for the offshore
waters still in effect till late tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 86 76 / 20 20 20 20
STT 86 74 86 76 / 30 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
153 PM AST Wed Dec 14 2016

.SYNOPSIS...A seasonable weather pattern will continue to
prevail across the local islands through Friday with showers
embedded in the trades at times, particularly across the USVI
and eastern Puerto Rico, as well as a few locally induced
afternoon showers...if any...across west PR. Prefrontal
shearline is forecast to reach the local area late Friday
into Saturday.


&&

.DISCUSSION...Mostly sunny skies prevailed across the local
islands this afternoon. Very light showers were noted over the
Caribbean coastal waters. A very dry airmass has moved across the
region. Latest TJSJ 14/12Z sounding showed precipitable water
values of 1.21 inches.

A mid to upper level ridge will continue to prevail across the
forecast area through Friday. Although some weakening is expected
particularly at upper levels Friday and into the upcoming weekend,
the mid level ridge will continue to hold through early next week.
Migratory surface highs north of the area will generally promote
fresh to locally strong trade winds with a prefrontal shearline
reaching the local area late Friday into Saturday. Under this
evolving pattern, expect a seasonable weather pattern with showers
embedded in the trades at times, particularly across the USVI and
eastern Puerto Rico, as well as a few locally induced afternoon
showers...if any...across west PR.


&&

.AVIATION...Mainly VFR conditions expected across all terminals
during the next 24 hours. However, trade wind showers could create
brief periods of -RA/VCSH across the Leeward/USVI and eastern PR
terminals through the entire forecast period. Low level winds will
continue mainly east at 15 to 20 kts.

&&

.MARINE...


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 86 76 84 / 10 10 20 20
STT 77 86 76 86 / 20 20 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
530 AM AST Thu Dec 15 2016


.SYNOPSIS...Mid to upper level ridge aloft will gradually erode
during the rest of the work week as a broad polar trough will
sweep eastward across the western Atlantic and reach the central
Atlantic late Friday into Saturday. A strong deep layered high
pressure ridge will quickly build across the west and southwest
Atlantic, behind this trough and the associated frontal boundary.
Surface high pressure across the central and eastern Atlantic will
shift farther east as a cold front will enter and move across the
west Atlantic through Friday. By the upcoming weekend, strong
surface high pressure ridge will build spread across the west and
central Atlantic as well as north of the region. This will tighten
the local pressure gradient once again.

&&

.DISCUSSION...
East to southeast tradewinds will prevail as the surface high
pressure recedes farther east of region and weak surface trough
sets up across the forecast areas today through Friday. Sufficient
trade wind moisture to bring some early morning clouds and showers
across the coastal waters and portions of the islands from time to
time. However the cloudiness is shallow and quick passing, so only
light to moderate showers are expected. This activity will diminish
by late morning leaving mostly sunny to partly cloudy skies.There
is still chance for isolated afternoon showers across the islands
today. For PR, activity should be focused mainly over parts of the
central and west interior sections of the island.

The gradual tightening of the local pressure gradient by the upcoming
weekend will lead to increasing east to northeast trade winds as
well as low level moisture convergence. This will lead to increasing
chance for late evening and early morning cloudiness as well as
more frequent light to moderate trade wind showers. This will be
followed by isolated to scattered afternoon convection over
portions of the central and west to southwest sections of PR.
Mostly isolated convection expected elsewhere during the daytime
each day.

&&

.AVIATION...Mostly VFR conditions expected across the local flying
area for the next 24 hours. However, VCSH are expected across TIST,
TISX and TJSJ during morning hours and over TJPS during Afternoon
hours...but will not expect any impact on operations. Surface winds
will remain mostly East-Northeast around 5 knots early this morning
increasing to 10-12 kts with occasional higher gusts after 15/13Z.

&&

.MARINE...Local buoys as well as model guidance suggest winds and
seas gradually diminishing and it is expected to continue to do so
today. However the offshore Atlantic buoy still suggest seas around
7 feet offshore. Therefore, the small craft advisory for the offshore
Atlantic waters will continue until 2 pm AST today. The rest of the
local waters will experience seas mainly between 3 and 6 feet. Small
craft should exercise caution.

As far as rip currents, most of the local beaches have a moderate
risk of rip currents.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 85 76 / 10 20 20 40
STT 84 75 87 76 / 20 20 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
203 PM AST Thu Dec 15 2016

.SYNOPSIS...
Ridge pattern aloft is expected to continue through at least next
week. A mid High pressure will promote a dry air mass at mid level
during the rest of the week. At low level...patches of moisture
are expected to move across the region at times. Under this
pattern, the U.S.V.I and east Puerto Rico can expect showers
embedded in the trades at times. Then, shallow afternoon
convection, if any, over the interior and west sections of Puerto
Rico, as well as downwind from the U.S. Virgin Islands are
possible each day. However, the frequency and intensity of showers
are expected to increase during the weekend as the mid to upper
level ridge slowly erodes over the islands.

&&

.DISCUSSION...
A mixture of sunshine and clouds prevailed today across Puerto
Rico and the U.S. Virgin Islands. The maximum local temperatures
were around the mid 80s across the coastal sections to low 80s
across the mountain areas. The rest of today, showers embedded in
the trades can be expected across the east and north sections of
Puerto Rico.

A patch of low level moisture is expected to reach the islands
overnight. As a result, the frequency of showers are expected to
increase over the eastern sections. GFS forecast sounding suggest
as slight increase in the available moisture on Friday afternoon.
This, combined with the local effect will result in afternoon
showers downwind from the U.S. Virgin Islands and over the
interior and Southwest section of Puerto Rico.

A mid to upper level ridge is expected to erode during the weekend
and into the upcoming week. Therefore, shower activity is
expected to increase in frequency and intensity over Puerto Rico
and the U.S. Virgin Islands during that period.

&&

.AVIATION...
VFR conds expected at all TAF sites through the forecast
period. However, brief MVFR conds will remain possible aft 15/22z
at JSJ/IST/ISX and the Leeward terminals in passing SHRA. Easterly
winds around 15 knots with sea breeze variations, becoming light
and variable overnight.

&&

.MARINE...Tranquil marine conditions are expected across most of
the local waters, with seas below 6 feet and winds around 15
knots. However, small craft operators should exercise caution
across the Atlantic Offshore waters due to seas up to 6 feet.
However, winds and seas are expected to increase after Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 85 76 83 / 20 20 40 40
STT 75 87 76 86 / 30 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
518 AM AST Fri Dec 16 2016

.SYNOPSIS...The upper level ridge will continue to erode today and
into the upcoming weekend, however model guidance still suggest
that mid level ridging is to hold across the forecast area for
the next several days. The dominant surface high pressure ridge
will continue to promote moderate to locally strong trade winds
today through the upcoming weekend as the local pressure gradient
will tighten in response to high pressure ridge building north and
east of the region.

&&

.DISCUSSION...
Recent model guidance and the overall pattern across the northeastern
Caribbean continued to suggest good transport of shallow trade wind
moisture with occasional passing showers across the region during
the next several days. Layered precipitable waters values will range
between 1.25 to 1.50 inches with most of this moisture trapped below
700 millibars. Periods of passing showers can therefore be expected
during the overnight and early morning hours, mainly over the coastal
waters and windward side of the islands. This will be followed by
partly cloudy to mostly sunny skies each day with isolated to
scattered afternoon shower activity, most of which will be of
short duration. This afternoon convection if any should be
focused across portions of central and west sections of PR.
Limited or no shower activity is expected over the rest of the
islands.

No significant rainfall is anticipated across the region at least
for the weekend and into early next week. However, latest model
guidance suggest better change for rainfall and increased instability
aloft during the latter part of next week, as tropical moisture
transport will increase across the region, and a mid to upper
level trough will return to the region.

&&

.AVIATION...Mostly VFR conditions expected across the local flying
area for the next 24 hours. However, VCSH are expected across TIST,
TISX and TJSJ during the morning hours with no impact on operations.
Surface winds will remain mostly from the East at around 5 knots
increasing to 10 knots after 16/13Z.


&&

.MARINE...


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 84 77 / 20 40 40 40
STT 86 76 86 76 / 30 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
436 AM AST Sat Dec 17 2016

.SYNOPSIS...Mid level ridge is expected to remain over the region
through at least Monday. This feature will limit the development
of widespread precipitation. However, the increase in the trade
winds across the region will induce an increase in the
development and frequency of trade wind showers over the local
islands. Showers are expected to be brief since they are expected
to move quickly, therefore the rainfall accumulations are still
expected to be modest.

&&

.DISCUSSION...Doppler radar indicated isolated to scattered
showers moving rapidly from the Atlantic waters across the U.S.
Virgin Islands, Vieques, Culebra as well across the northern and
eastern sections of Puerto Rico overnight and early this morning.
This activity was associated with the increase in trade winds
across the northeast Caribbean. For the rest of the morning hours,
a mixture of sunshine and clouds with passing showers will prevail
mostly across northern and eastern Puerto Rico and across the
U.S. Virgin Islands. For this afternoon this activity will
continue to encompass the region affecting also the western
interior and southwest sections of Puerto Rico. A similar pattern
is expected to prevail across the region tonight and Sunday, but
widespread precipitation is not expected at this time.

GFS model guidance suggests a developing mid to upper level
trough across the northeast Caribbean by early next week. If this
materialize, a relatively wet weather pattern will encompass the
region during the upcoming week, resulting in a increase in
showers and possible thunderstorms across the forecast area.

&&

.AVIATION...VFR conditions expected across all terminals for the
next 24 hours. Trade wind shower activity will prevail through the
forecast period. This could result in -RA/VCSH at times across the
USVI/northern PR and Leeward terminals. ENE surface winds expected
to increase from 10-15 kts to 15-20 kts with higher gusts during
early Saturday morning.

&&

.MARINE...Small craft advisories will go into effect starting
early today. An increase in winds from the ENE with a northerly
swell will cause hazardous seas. A high risk of Rip Currents is
expected today for the northwest beaches of Puerto Rico as for
some beaches of St Croix. Latest marine guidance is suggesting
that the local seas will be hazardous for the next several days.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 76 83 77 / 40 30 30 40
STT 87 75 87 75 / 40 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
158 PM AST Sat Dec 17 2016

.SYNOPSIS...Mid to upper level ridge will hold the rest of the
weekend...gradually eroding early next week as upper level trough
will amplify just northeast of the region. A trade wind pattern
will prevail across the region over the next few days...with
passing showers affecting the windward areas at times. A wetter
and somewhat unstable pattern is forecast from Tuesday through at
least Friday as upper trough will dominate across the region.

&&

.DISCUSSION...Surface high pressure north of the local area is
generating a fresh to locally strong winds over Puerto Rico and
the U.S. Virgin Islands. The brisk easterly winds have pushed
clouds and scattered showers across portions of the local islands.
These fast moving showers have produced light rainfall amounts
over most of Puerto Rico and the U.S Virgin Islands so far this
afternoon. This pattern of trade wind showers are expected to
continue across the local islands the rest of the weekend. With a
mid-upper level ridge dominating the local area...the chance of
thunderstorms is low through Sunday.

Conditions will become moist and unstable on Monday/Tuesday as an
upper level trough will amplify over the Northeast Caribbean and
Tropical Atlantic. In addition...winds will subside across the
local region as surface high pressure moves over the Eastern
Atlantic. Therefore...sea/land breezes will play a big role in the
development of showers the upcoming week. The chances of thunderstorms
will also increase especially around midweek when the upper trough
reaches the maximum amplitude.

&&

.AVIATION...Patches of low level moisture are expected to produce
passing showers en route btwn the Leeward Islands and the U.S.
Virgin Islands. Some of these -SHRA/SHRA will are expected mainly
across TJSJ/TJBQ/TISX/TIST/TNCM/TKPK. Embedded clouds in the
trades will result in SCT-BKN cld lyrs between FL020 and FL040 at
times. Passing clouds and -SHRA/SHRA will continue across the
region during the next 24 hrs. SFC winds from E/NE btw 15-25 kts
with higher gusts are expected to continue through at least
Sunday.

&&

.MARINE...Fresh to strong trade winds are expected to continue
through the weekend. This wind flow will promote hazardous marine
conditions. Therefore, Small Craft Advisories are in effect
across most of the local waters of Puerto Rico and the U.S. Virgin
Islands. For the beach goers...a high risk of Rip Currents is
expected at most of the beaches the rest of the weekend. Please,
refer to the Surf Zone Forecast for additional information.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 84 77 83 / 40 30 40 40
STT 75 87 75 85 / 40 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
455 AM AST Sun Dec 18 2016

.SYNOPSIS...Mid level ridge will remain over the region through
Monday. Trade winds passing showers will continue to affect the
windward areas of the local islands for the next few days. Showers
are expected to be brief since they are expected to move quickly,
producing only modest rainfall accumulations. An upper level
trough is expected to amplify across the northeast Caribbean early
in the week. This feature will result in a more wet weather
pattern for most of the week.

&&

.DISCUSSION...Doppler radar indicated isolated to scattered
showers moving rapidly from the Atlantic waters across the U.S.
Virgin Islands, Vieques, Culebra as well across the northern and
eastern sections of Puerto Rico overnight and early this morning.
This activity was associated with the increase in trade winds
across the northeast Caribbean induced by a strong surface high
pressure northeast of the region.

The surface high pressure will continue to produce fresh to
locally strong winds across the local islands and the surrounding
coastal waters until early in the week. These winds will continue
to push showers across portions of the local islands and
surrounding waters, but due to presence of the mid level ridge
over the region, not widespread or significant precipitation is
expected at this moment.

GFS model guidance suggests a developing mid to upper level
trough across the northeast Caribbean early in the week. If
this situation materialize, a relatively wet weather pattern will
encompass the region late Monday and Tuesday and thereafter. This
scenario will result in a increase in shower and possible
thunderstorm activity across the forecast area specially by the
middle of the week.

&&

.AVIATION...Strong trade wind flow at the surface is carrying SCT
mdt-hvy SHRA across the fcst area. Brief MVFR conds are occurring
mainly due to cigs FL015-030. SHRA are expected to increase aft
18/14Z. Mtn obscurations are indicated through 19/02Z. Sfc winds E
10-20 kt in unprotected areas increasing to 15-25 kt aft 18/12Z.
LVL winds easterly and reaching up to 35 kt at FL070. Otherwise
winds NE-E 20-30 kt up thru FL240, backing aft that to bcm NW 50
kt at FL430.

&&

.MARINE...Fresh to strong trade winds are expected to continue
through early this week. This wind flow will continue to promote
hazardous marine conditions. Therefore, Small Craft Advisories are
in effect across most of the local waters of Puerto Rico and the
U.S. Virgin Islands. For the beach goers...a high risk of Rip
Currents is expected to continue at most of the beaches the rest
of the weekend. Please, refer to the Surf Zone Forecast for
additional information.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 77 83 74 / 30 40 40 40
STT 87 75 85 74 / 30 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
152 PM AST Sun Dec 18 2016

.SYNOPSIS...A trade wind pattern will prevail across the region
over the next few days...with passing showers affecting portions
of the islands at times. A wetter and somewhat unstable pattern
is forecast from Tuesday through at least Friday as upper trough
will dominate across the region.

&&

.DISCUSSION...Surface high pressure over the Central Atlantic is
producing breezy to windy conditions over Puerto Rico and the
U.S. Virgin Islands. Several weather stations have reported wind
gusts in excess of 30 MPH. This brisk easterly flow have pushed
clouds and scattered showers across portions of the local islands
since this morning. Showers have moved quickly across the local
area resulting in light rainfall accumulations. A similar pattern
is forecast on Monday with passing showers affecting the islands
from time to time. The windward areas will experience most of the
activity.

Conditions will become more unstable on Tuesday/Wednesday as an
upper level trough will amplify over the Northeast Caribbean and
Tropical Atlantic. At the same time...low level winds will subside
across the local region as surface high pressure moves farther
east over the Eastern Atlantic. Therefore...sea/land breezes will
play an important role in the development of showers this week.
The chances of thunderstorms and higher rainfall accumulations
will increase around midweek when the upper trough reaches the
maximum amplitude.

Operational models continue to suggest a moist and unstable conditions
the second part of the week and the Christmas Weekend. However...we
will continue to monitor the model solutions over the next few days
to see how this pattern unfolds.

&&

.AVIATION...
Passing -SHRA/SHRA en route btwn the Leeward Islands and the U.S.
Virgin Islands are expected through the afternoon. Some of these
-SHRA/SHRA will move across TJSJ/TJBQ/TISX/TIST/TNCM/TKPK. Trade
wind showers will result in SCT-BKN cld lyrs between FL018 and
FL040 at times. Activity should diminish btwn 18/22-19/06z.
However, another round of frequent -SHRA/SHRA with brief MVFR
cigs will return after 19/06z. E to NE winds btwn 13-29 kt with
higher gusts are expected to continue through the fcst period.

&&

.MARINE...Hazardous marine conditions with seas between 6 and 8
feet and occasional seas up to 10 feet are expected through the
next few days. In addition, fresh to strong winds will continue
across most of the local waters. Therefore, a Small Craft Advisories
continue in effect at least until Monday evening. For the beach
goers, there is a high Rip Current Risk for most of the local
beaches through at least Monday evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 83 74 81 / 40 40 40 40
STT 75 85 74 85 / 40 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
405 AM AST Mon Dec 19 2016

.SYNOPSIS...At upper levels...A trough will swing across the area
today, but reform north of Puerto Rico and the U.S. Virgin Islands
on Tuesday. Short waves in the trough will move through the area
Wednesday and Thursday with diminishing intensity until a ridge
builds south of the area and shifts east toward the end of the
week, bringing southwesterly flow. Upper level dynamics are
generally negative despite another broad trough and subsequent jet
passage in the first half of next week.

At mid levels...High pressure north of the area will persist
through the week, shifting into the east central Atlantic by the
weekend. High pressure builds over the eastern coast of Florida
next Monday. Mid level moisture becomes better during the week and
diminishes again on Sunday.

At lower levels...A 1043 mb high pressure over the northeastern
Atlantic will fade during the week, but high pressure will
continue north of the area the entire time driving moderate to
strong trade winds. Moisture at lower levels continues but peaks
today according to the GFS.

&&

.DISCUSSION...Had to back off a draft forecast with very high POP
values as moisture has not yet formed good shower coverage for the
windward sections of Puerto Rico and the U.S. Virgin Islands.
Nevertheless the GFS and most of the finer scale models agree on
increasing shower activity through 19/15z--mainly on the coast.
And activity will increase during the morning so that rain is
likely over most windward coasts and slopes of Puerto Rico. With
dry mid levels for the moment tops are not likely to grow beyond
25 kft, so thunderstorms are not expected today.

Low level moisture never reaches Monday`s peak but scattered
rapidly passing showers will move through the area on moderate to
strong trade winds. Most models keep winds strong today and begin
relaxing the gradients slightly Tuesday and Wednesday. But lower
level support for fresh winds does not abate until the weekend.

&&

.AVIATION...Mostly VFR conditions expected across the local
flying area through the forecast period. However, trade wind shower
activity will continue through the forecast period. This can result
in -SHRA/VCSH at times across the USVI/eastern PR and Leeward
islands terminals. ENE surface wind gusts expected to increase to
around 30 kt after 19/13z. The 19/00z TJSJ sounding data indicated
ENE winds at 30-42 kt between FL050-FL100. Would expect some
mountain obscurations and at least moderate turbulence in vicinity
of the mountains.

&&

.MARINE...The normal diurnal increase in winds will occur again
this morning and seas will likely reach 7 feet in all but the
most protected areas if they have not reached this level already, with
outer waters occasionally seeing 10 feet. All but the southwestern
beaches will see a high risk of rip currents and breaking waves up
to 9 feet. Conditions will slowly improve Tuesday through Friday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 75 84 74 / 60 60 60 40
STT 86 75 84 74 / 50 60 60 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
155 PM AST Mon Dec 19 2016

.SYNOPSIS...
An upper level trough extending from the North-East Caribbean
into the Central Atlantic will amplified through mid week. A short
wave trough is expected to move from the west over the local
region by the end of the work week. A strong surface high pressure
over the Central Atlantic is promoting breezy to windy conditions
across the region. Strong winds combined with surges of surface
moisture will continue to advect shallow clouds and showers across
the islands at time.

.DISCUSSION...
A strong surface high pressure brought patches of clouds and trade
wind showers across the region. The strongest activity was
observed over the islands of St Thomas, St John, St Croix and the
surrounding waters. The trade winds will continue to push bands of
clouds and showers across the region this afternoon and into the
evening. As a result, partly to mostly cloudy skies with frequent
passing showers are expected to continue across the islands at
times.

As the ridge weakens and the trough aloft deepens over the
region, conditions will become more moist and unstable. This
pattern will support a better chance for organize convection
across the region.

&&

.AVIATION...
SCT SHRA en route to PR and USVI. This may result in brief
MVFR/IFR conds as SHRA pass by. Easterly winds of 20-30 kts below
15k feet.

&&

.MARINE...
Hazardous marine conditions are expected to continue through at
least midweek. Therefore, a small craft advisories are in effect
for the local waters, except across the southwest coastal waters
of Puerto Rico. In addition, this hazardous conditions will also
result in a moderate to high risk of rip currents across most of
the beaches in Puerto Rico and the U.S. Virgin Islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 84 74 83 / 40 50 40 40
STT 75 84 74 85 / 20 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
517 AM AST Tue Dec 20 2016

.SYNOPSIS...Moist flow in fresh to strong trade winds will produce
showers each day. A pocket of cold air in a mid and upper level
trough will enhance showers and thunderstorms today and tomorrow.

At upper levels...The trough over Puerto Rico and the
U.S. Virgin Islands shifts north by Wednesday night. Beginning
Thursday southwest flow develops over the area as a ridge develops
over the southeast Caribbean and the equatorial Atlantic.

At mid levels...High Pressure continues from the Gulf of Mexico
east northeast into the Atlantic. Weak cold-core low pressure is
found over Puerto Rico today and Wednesday that will gradually
disappear over the weekend when high pressure ridges east from
Florida. Thereafter high pressure will dominate the Bahama islands
and Cuba and overflow into the local area. Mid level moisture will
increase today through Friday, then drop off next week when flow
switches to northeast.

At lower levels...Strong high pressure over the northeast central
Atlantic will shift eastward toward the Azore islands. High
pressure will move from the mid-Atlantic seaboard into the western
Atlantic ocean over the weekend maintaining fresh to strong trade
winds over much of the sub-tropical and tropical Atlantic.

&&

.DISCUSSION...Rapidly moving showers continued across the local
waters and onshore over eastern and northern Puerto Rico. Cold air
aloft is enhancing the instability and has generated some
thunderstorms over the Atlantic waters and around the U.S. Virgin
Islands. The center of this cold pocket will be 2 standard
deviations below normal and will settle over Puerto Rico today
and slowly warm. Active showers and isolated thunderstorms may
continue after Wednesday, but the upper level trough will give way
to a ridge building from the southeast afterwards. Pockets of
divergence aloft will likely enhance showers activity later in the
week and over the weekend as upper level flow turns southwest, but
convergence will generally prevail at upper levels. Still too
early to get a handle on Christmas Eve and Christmas Day, but
shower are likely--mainly on the windward coasts.

&&

.AVIATION...Brief MVFR conds will remain possible at Leeward and
USVI TAF sites as well as JBQ/JSJ in passing SHRA with isolated TSRA
through the forecast period. Mountain obscurations expected. ENE
surface winds of 15-20kts to continue with gusts to 30 kt at
times.

&&

.MARINE...Marine conditions remain hazardous during the next
several days. Waves remained above 10 feet in easterly seas at
buoy 41043 north of the forecast area and between 7 and 8 feet
overnight at the local inner buoy near San Juan. A pocket of cold
air has increased instability considerably and thunderstorms have
been observed over Atlantic waters and around the U.S. Virgin
Islands all night--spreading west into the Mona passage. This has
created very gusty conditions. Small craft advisory conditions
will continue over outer waters and passages for much of the week.
Inner waters will see some improvement after mid-week. Rip
currents will begin to subside after today, but moderate to high
risk applies to most of the coasts of Puerto Rico and the U.S.
Virgin Islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 75 83 76 / 60 50 40 40
STT 84 74 85 74 / 50 40 40 40