Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
115 PM AST Fri Feb 17 2017

.SYNOPSIS...An upper level ridge will continue as the main weather
feature across the region local islands for the next several
days. This feature will maintain a generally fair and stable
weather pattern across the local islands during the upcoming
weekend. An upper level trough is expected to amplify over the
region early next week, inducing and increase in cloudiness and
showers across the local islands.

&&

.DISCUSSION...Mostly sunny skies were observed across the local
islands this afternoon. Doppler weather radar detected only few
isolated showers were detected over the coastal waters, but not
significant precipitation was observed over land areas so far this
afternoon. The limited moisture across the region in combination
with daytime heating and local effects is possible to induce some
showers across western and interior sections of Puerto Rico late
this afternoon and this evening. The GFS model guidance suggests
that PWAT values will remain near 1.00 inch during the next few
days. These values do not support the development of any
significant shower activity over the region for the next few days.

A surface high pressure will move over the southwestern Atlantic
tonight and Saturday inducing a northeast low level wind flow
across the northeast Caribbean and pushing a weak frontal
boundary across the local Atlantic coastal waters late in the
weekend and early next week. An upper level trough is also expected
to amplify over the region early next week, inducing and increase
in cloudiness and showers across the local islands. Dry air will
return to the region by midweek.

&&

.AVIATION...Mainly VFR conditions will prevail across all terminals
through the forecast period. Isolated showers still possible late
this afternoon across the interior and western sections of PR.
This could result in VCSH at TJMZ. Low level wind ESE at 10 kts
or less.

&&

.MARINE...Offshore and nearshore buoys indicated seas of 3-4 feet
across the region. Seas will increase to 3-5 feet on Sunday as
another small swell reaches the local Atlantic Waters. No small
craft advisories are anticipated over the next 5 days. Gentle
winds will prevail today, increasing somewhat as shift from the
northeast during the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 84 72 85 / 0 0 10 10
STT 71 84 73 83 / 0 10 10 10

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
450 AM AST Sat Feb 18 2017

.SYNOPSIS...Fair weather pattern will prevail across the islands
most of the weekend. Then...moisture associated with a weak front
will spread over the islands late Sunday into Monday. Potent upper
level trough will swing across the Northeast Caribbean early next
week...increasing the chances of showers across the local area.
Drier and more stable air mass will return to the region by
midweek next week.

&&

.DISCUSSION...Satellite imagery depicts a weak front just north of
Puerto Rico this morning. A dry air mass have been prevailing
across the local islands resulting in mostly clear skies and no
shower activity. This tranquil conditions will likely persist the
rest of today. However...the sea breeze convergence will lead to
isolated to scattered showers over portions of Southwest Puerto
Rico this afternoon. Elsewhere...mostly sunny skies and limited
shower activity are forecast under the influence of the mid-upper
level ridge. Gentle easterly winds and near normal temperatures
will prevail through tonight.

The ridge aloft will hold the rest of the weekend...however
moisture associated with the weak front will spread over Puerto
Rico and the U.S. Virgin Islands by Sunday afternoon. As a
result...moderate northeasterly flow will push some showers over
the islands from time to time. Afternoon showers will be possible
once again over Western PR on Sunday afternoon.

Conditions will become moist and unstable as moisture associated
with the remnants of the front persists over the local islands
and upper level trough enhances the instability. At this time...
wetter conditions are likely between Monday and Tuesday under the
influence of the upper level trough. Dry air will return to the
local islands by midweek... leading to fair weather conditions.

&&

.AVIATION...Mainly VFR conditions will prevail across all terminals
through the forecast period. SHRA with max tops around FL250 should
remain over the offshore Atlantic waters due to a weak front. Brief
SHRA expected to develop across the southwest quadrant of PR between
18/18z-22z. This could result in VCSH at JMZ/JPS. Low level winds
ENE at 8-15 kts. Sea breeze variations after 18/13z.

&&

.MARINE...Relatively tranquil conditions are prevailing across the
regional waters. Winds of 5-10 kts and seas of 2-4 feet will continue
to prevail through tonight. Winds will increase slightly and seas
will build to 4-6 feet on Sunday as a northerly swell reaches the
local Atlantic Waters and Caribbean Passages. Tranquil conditions
will return to the region early in the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 73 84 74 / 0 10 10 10
STT 84 72 83 73 / 10 10 10 10

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
155 PM AST Sat Feb 18 2017

.SYNOPSIS...Cold front north of the area will remain nearly
stationary while weakening. Another cold front will exit
southeastern U.S. during the weekend. A strong high pressure is
expected to push this front southeast by late Monday into Tuesday
increasing the chances for showers across the local islands. An
upper level trough will develop across the western Atlantic by
Monday and Tuesday, enhancing the shower activity.

&&

.DISCUSSION...Very dry weather conditions prevailed across the
local area this morning and early this afternoon. The only
activity detected by the doppler radar was a line of showers
located near 150 miles north of Puerto Rico. This line of showers
was nearly stationary. The activity it is associated with a
weakening cold front which is expected to remain stationary or
with little movement next couple of days. This feature is not
expected to affect the local region.

Another cold front, in combination with and upper level trough are
expected to affect the local region Monday night and Tuesday. At
this time, the better dynamics are expected on Tuesday as the
aformentioned upper level trough moves closer to the region.

&&

.AVIATION...VFR conditions are expected to prevail across all TAF
sites through the forecast period. Low level winds will continue
light and variable through Sunday. Winds will increase somewhat
Sunday afternoon becoming northeasterly at 10 kts.

&&

.MARINE...Latest buoys observations indicated seas were starting
to increase across the offshore Atlantic waters. This trend will
continue as a northerly swell reaches the local Atlantic Waters
and Caribbean Passages. Seas increasing to 5 feet tonight are
expected over these waters.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 84 73 84 / 10 10 10 30
STT 72 82 73 82 / 10 10 10 20

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
459 AM AST Sun Feb 19 2017

.SYNOPSIS...A weak frontal boundary over the local Atlantic Waters
will dissipate over the next few days. Moisture associated with the
front will pool across the local islands through Monday. Upper level
trough will move into the Western Atlantic tonight and swing across
the Northeast Caribbean on Monday...increasing the chances of showers
across the local area. Drier air mass will return to the region between
Tuesday and Wednesday.

&&

.DISCUSSION...Satellite derived precipitable water analysis as
well as latest surface analysis show a frontal boundary extending
from the Central Atlantic to the Northeast Caribbean Region.
Although...mid level ridge will hold through tonight...moisture
associated with the weak front will reach the local islands...
inducing scattered showers across the forecast area during the
next 24-48 hours. For today...some showers will affect the north
coast of Puerto Rico through after sunrise...followed with
scattered showers over Western Puerto Rico this afternoon.

Conditions will become more unstable late tonight into Monday as
an upper level trough amplifies across the Northeast Caribbean
Region. The trough aloft will enhance the convective instability.
Therefore...shower coverage will likely increase on Monday.

After the front passes/dissipates, a generally fair weather pattern
will likely establish between Tuesday and Wednesday. Northeast winds
will bring low clouds along windward slopes and cooler temperature
across most of the forecast area.

&&

.AVIATION...VFR conditions will prevail across all terminals through
much of the forecast period. However, SHRA and BKN/OVC cigs btw
FL070-FL120 over the Atlantic waters could reach the northern
sections of PR and IST early in the forecast period. From 19/18z-
23z, SHRA is expected to develop across the northwest quadrant of
PR. This can result in tempo MVFR conditions at JBQ/JMZ. Low level
winds light from the ENE through at least 19/12z...ESE at 10-15 kts
with sea breeze variations after 19/13z.

&&

.MARINE...A moderate swell will continue to reach the Local
Atlantic waters through late tonight. Seas of 4-6 feet in north
swell have increased the risk of rip current along the north coast
of Puerto Rico. Seas will gradually subside Tuesday and Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 73 86 76 / 20 10 30 50
STT 81 74 80 73 / 10 20 20 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
104 PM AST Sun Feb 19 2017

.SYNOPSIS...A dissipating frontal boundary across the local Atlantic
Waters will continue to induce cloudiness and occasional light to
moderate showers across the local islands through Monday.
An upper level trough over the southwestern Atlantic is expected to
move across the Northeast Caribbean tonight and Monday slightly
increasing the chances of showers across the local area. Drier and
stable air mass is expected to encompass the region again Tuesday
and Wednesday.

&&

.DISCUSSION...Doppler weather radar indicated an area of
cloudiness and showers moving from the Atlantic coastal waters
across the northern and central sections of Puerto Rico this
afternoon. This activity was associated with a dissipating frontal
boundary across the northeast Caribbean. The associated moisture
will continue to move across the northern sections of Puerto Rico as
well as across Vieques, Culebra and the U.S. Virgin Islands tonight
through Monday. However, only light to moderate shower activity is
expected.

An upper level trough over the southwestern Atlantic this afternoon
is expected to amplify across the northeast Caribbean tonight and
Monday. This feature in combination with the moisture provided by
the aforementioned frontal boundary will result in an increase in
cloudiness and showers activity tonight through early Monday. A
general dry and stable weather pattern will encompass the region
Late Tuesday and Wednesday.

&&

.AVIATION...Mainly VFR conditions will continue across the local
flying area through much of the forecast period. However, SHRA and
BKN/OVC cigs will affect some of the local terminals as a frontal
boundary dissipates over the region tonight and early Monday. Light
low level winds from the East to ESE will prevail tonight.

&&

.MARINE...A moderate swell will continue to reach the Local
Atlantic waters through late tonight. Seas of 4-6 feet in north
swell have increased the risk of rip current along the north coast
of Puerto Rico. Seas will gradually subside Tuesday and Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 86 76 82 / 10 30 50 20
STT 74 80 73 80 / 20 20 50 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
451 AM AST Mon Feb 20 2017

.SYNOPSIS...Trough pattern aloft and induced surface trough across
the western Atlantic will move across the forecast area today.
This will enhance showers and possible thunderstorm development
over the northern interior of PR and across the Atlantic waters
this afternoon. Winds will shift to the south to southwest today
and become northerly late tonight into Tuesday as the trough moves
over the islands and surface high build over the western Atlantic
by mid week. Upper Ridge will build quickly from the west on
Tuesday and hold for the rest of the work week.

&&

.DISCUSSION...Cloudy skies were observed across mainland PR
through the overnight hours. Light showers persisted over portions
of the western coastal areas of the islands through the overnight
hours. However, no significant rainfall accumulations were
observed. Clear to partly cloudy skies prevailed across the U.S.
Virgin Islands through the overnight period. Light winds with an
easterly component continued across the forecast area. Moderate to
brief heavy isolated showers were noted over both Atlantic and
Caribbean coastal waters.

For the rest of the morning hours, a few breaks in clouds and
fair weather conditions are expected to prevail. However, a mid to
upper trough and associated surface trough will move during the
afternoon through evening hours across the forecast area. This
will result in periods of showers with possible thunderstorm
development over the Atlantic waters and north of the Cordillera
Central. Drier conditions and fair weather conditions are expected
to return on Tuesday and persist for much of the work week. Trade
wind shower activity and limited afternoon shower development is
expected each day after today.


&&

.AVIATION...Weak front over the flying area will keep SCT-BKN clouds
at FL025-FL070 and -SHRA at times. SHRA/ISOLD TSRA will develop near
TJSJ between 17Z-22Z. Brief MVFR conds possible the afternoon SHRA
at TJSJ. Elsewhere, mostly VFR expected. ESE Winds of 10 kts will
veer to the SSW by 18Z.

&&

.MARINE...Latest buoy data at San Juan and Rincon are indicating
seas less than 5 feet and therefore canceled the high risk of rip
currents. However, a moderate risk of rip currents will continue
across the Atlantic coastline of PR, Culebra and St. Thomas. Winds
will be mainly light with a southwesterly component later in the
day as the low level trough moves from the northwest across the
local waters. This can result in scattered to numerous showers
with possible thunderstorm development over the Atlantic waters.
Seas should range between 3-5 feet over the northern waters and
below 4 feet across the Caribbean waters.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 82 73 / 50 40 40 30
STT 82 73 82 72 / 20 60 50 30

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
144 PM AST Mon Feb 20 2017

.SYNOPSIS...Trough pattern aloft and a surface trough across the
western Atlantic will continue to approach the local region the
rest of this afternoon and tonight. Low level winds will be
variable and are expected to shift to the north and northeast by
Tuesday as a high Pressure system builds across the western
Atlantic.

&&

.DISCUSSION...A very dry and stable air mass moved across the
region this morning. No shower activity was observed over land
areas. A very dry and stable air mass encompassed the local region
this morning and early afternoon which kept the local area under
mostly sunny skies. However, this could change in the next few
hours as a surface trough in combination with trough pattern
aloft are expected to destabilize the local atmosphere which will
result in better chance for showers and even thunderstorms later
this afternoon and tonight. The shower and thunderstorm activity
is expected to occur mainly across the Atlantic waters and along
the north and east sections of Puerto Rico, and later tonight over
the U.S. Virgin Islands.

This slightly wetter pattern is expected to linger through
Tuesday morning. Global models indicated a very dry air mass will
move behind the trough Tuesday afternoon as an upper level ridge
builds across the western Atlantic. As a result, a return to a
normal weather pattern for the month of February is then expected
from Tuesday afternoon and beyond.

&&

.AVIATION...VFR conds across the local terminals. Developing SHRA
could affect the vicinity of TJSJ after 20/19Z. Southwesterly wind
is expected this afternoon across most of the terminals except for
the terminals of northern PR where westerly winds are expected. SCT
SHRA activity moving in tonight. So VCSH is expected through many of
the local terminals after 21/00Z. Winds are expected to gradually
become WNW for the overnight hours at 10-15KT.

&&

.MARINE...Seas will continue to improve across the local waters
through Tuesday. Seas up to 5 feet diminishing to 4 feet are
expected over the coastal waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 82 73 83 / 40 40 30 30
STT 73 82 72 83 / 60 50 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
458 AM AST Tue Feb 21 2017

.SYNOPSIS...Upper trof north of the area and associated weak
surface boundary will continue to move to the east and exit the
forecast area today. Ridge pattern will follow from the west and
drier fair weather is expected to prevail for the rest of the
week. Northerly winds will shift to the southeast on Thursday as
surface high moves north of the area.

&&

.DISCUSSION...Scattered to numerous showers with isolated
thunderstorms over the Atlantic coastal waters moved across the
forecast area during the overnight. The heaviest showers remained
just north of the northern USVI. For the next few hours
additional showers are expected to move across the islands but
sunny skies are expected to return by the late morning hours.
Overnight temperatures were in the low to mid 60s across the
higher elevations to the low 70s across coastal areas.

Overall fair weather conditions are forecast to prevail for the
rest of the week as ridge pattern builds from the west and cap
inversion keep moisture below 800 MB. However, diurnally induced
afternoon showers cannot be ruled out each day and trade wind
showers should prevail across the northern and eastern coastal
areas through Thursday. Another upper trof and associated surface
boundary are forecast to move north of the area by late Sunday
enhancing shower activity once again.

&&

.AVIATION...SCT SHRA will affect the flying area thru 14Z. As a
result, MVFR cigs are possible in passing SHRA across TJBQ,TJSJ and
TIST. VFR conds are expected after 14Z...with limited shower
activity over the region. West winds of 10-15 kt will continue below
FL150.

&&

.MARINE...Small pulses of northerly swell are forecast to reach
the regional waters for the next few days. Swell is expected to
peak on Friday morning between 4-6 feet. There is a moderate risk
of rip currents along the northern beaches of the islands.
West to northwest winds between 10-15 knots will continue today as
weak frontal boundary moves across the local area.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 72 83 71 / 20 20 20 30
STT 82 74 82 72 / 50 20 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
145 PM AST Tue Feb 21 2017

.SYNOPSIS...A seasonable weather pattern is expected to prevail
during the next several days as a mid to upper level trough moves
away and a ridge pattern builds across the forecast area. Above
normal temperatures are likely by the end of the week and into
the upcoming weekend.

&&

.DISCUSSION....Partly cloudy skies and brief passing showers
along the northern half of Puerto Rico and the USVI prevailed
during the morning hours as well as early in the afternoon.
Temperatures were generally in the low to mid 80s under a
northerly wind flow at 15 to 20 mph.

A mid to upper level trough with its associated surface low
across the northeast Caribbean will continue to move southeast
and away from the forecast area tonight while weakening. As
this feature moves away; a ridge pattern will build across the
forecast area tomorrow and hold through early next week.

At lower levels, northerly winds will continue to prevail tonight
and tomorrow becoming southeast Thursday and into the upcoming
weekend as a surface low develops across the southwest Atlantic.

Therefore under the aforementioned pattern and guidance
suggesting precipitable water near or slightly below the normal
values, continue to expect a seasonable weather pattern with trade
wind showers in the morning and evening hours followed by limited
afternoon convection. The southerly wind flow which is expected
Thursday and into the upcoming weekend likely to result in above
normal temperatures along the northern slopes of Puerto Rico.

&&

.AVIATION...VFR conditions are expected to prevail across all TAF
sites through the forecast period. Some light passing showers can
be expected in the vicinity of TNCM, TKPK, TIST, TISX and TJSJ
tonight. Low level winds will be mainly North at 10 kts.

&&

.MARINE...Small pulses of northerly swell are forecast to reach
the regional waters during the next few days with swell action
expected to peak Friday morning. There is a moderate to high risk
of rip currents along the Atlantic shoreline with seas between 5
and 6 feet this afternoon. Seas and winds subsiding overnight
with seas around 5 feet.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 72 83 71 86 / 20 30 30 30
STT 74 82 72 83 / 20 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
452 AM AST Wed Feb 22 2017

SYNOPSIS...Deep layered area of low pressure and associated polar
trough was now located across central Atlantic and northeast of
the northern leewards. The trough axis extends southwest across
the lesser antilles and will continue to shift east southeast.
The departing trough along with a broad surface high pressure
moving across the west Atlantic will continue to induce a
northerly flow across the region today. The Low level winds are
expected to remain dominant from the north through the early
afternoon, then gradually become more to northeasterly later in
the afternoon and overnight as the high pressure ride migrates
eastward across the Atlantic. The prevailing wind flow is then
expected to return east to southeast by Thursday and Friday as
the ridge will move into and then linger across the central
and northeast Atlantic into the weekend.

&&

.DISCUSSION...Under the influence of northerly winds, expect isolated
to scattered fast moving showers mainly of light to moderate intensity
mainly along the northern coast of Puerto Rico and the USVI during
the rest of the early morning hours. By the late morning and early
afternoon, cloudiness and shower activity should diminish along the
north coastal areas. During the rest of the day,cloud development
should then be focused along central mountain range and the south
coastal plains of Puerto Rico. Elsewhere expect only brief streamer
like shower activity during the afternoon hours as mostly fair weather
and sunny skies should prevail with pleasant daytime temperatures
and limited shower activity.

On Thursday and by the end of the week expect the trade winds to become
more southeasterly as the high pressure ridge shifts eastward across
the Central Atlantic,c and a cold front will enter and move across
the west Atlantic. This expected southerly low level wind flow will
bring warmer temperatures especially along the north coastal areas
and an even drier airmass to the region. Therefore looking for
unseasonably warmer temperature at least for Friday through Saturday
along the northern half of PR, then a return to near normal temperature
by Sunday into early next week. So far no significant weather maker
in sight for the next several days.

&&

.AVIATION...Mostly VFR conditions expected across the local flying
area for the next 24 hours. Some light and brief showers can be
expected in the vicinity of the terminals this morning. Low level
winds are expected to be more from the NE to ENE after 22/12Z at
about 10 KT with sea breeze variations. SCT SHRA expected to develop
across southern PR after 22/18Z inducing VCSH at TJPS and possibly
affect the terminal at times between 22/18Z and 22/23Z.

&&

.MARINE...Seas and winds will diminish somewhat early today to 5
feet or less and up to 10 knots over the coastal waters. However a
gradual increase in winds and seas is expected later this afternoon
and for the rest of the week with seas up to 7 feet expected to
approach the offshore Atlantic waters by Thursday and Friday due
to pulses from a northerly swell. There is a moderate risk of rip
currents for most of the north facing beaches of the islands. The
increasing winds and seas by the latter part of the week will again
cause the risk of rip currents to become high again on Thursday and
Friday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 73 86 73 / 30 30 30 20
STT 84 74 82 73 / 30 30 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
147 PM AST Wed Feb 22 2017

.SYNOPSIS...A seasonable weather pattern is expected to prevail
during the next several days with passing showers across windward
areas followed by limited afternoon convection across the western
quadrant of Puerto Rico each day. Above normal temperatures are
likely by the end of the week and into the upcoming weekend.

&&

.DISCUSSION...Partly cloudy skies and brief passing showers along
the coastal areas of northeast Puerto Rico as well as the USVI
prevailed during the morning hours and early in the afternoon.
Temperatures were generally in the low to mid 80s under a
northeasterly wind flow at 15 mph.

A seasonable weather pattern will continue to prevail across
the local islands through early next week under a building mid
level ridge and near normal precipitable water. In fact, the
day with the best moisture advection is tomorrow during mid
day. Latest guidance suggests that precipitable water may reach
the above normal range on Monday. However, through the forecast
period the mid levels will remain dry. At lower levels, the
northeast winds will continue to prevail through tonight becoming
southeast Thursday morning as a surface low prevails across the
southwest Atlantic and a surface high north of the area shifts
further east.

Therefore under the aforementioned pattern, continue to expect
trade wind showers in the morning and evening hours followed by
limited afternoon convection. The southerly wind flow will likely
to result in above normal temperatures along the northern slopes
of Puerto Rico Thursday and into the upcoming weekend.

&&

.AVIATION...Mostly VFR conditions expected across the local
flying area for the next 24 hours. Some light and brief showers
can be expected in the vicinity of the terminals tonight. Low
level winds are expected to be from the NE to ENE after 22/22Z
at about 10 KT.

&&

.MARINE...A gradual increase in winds and seas is expected later
today and for the rest of the week with seas up to 7 feet expected
to approach the offshore Atlantic waters by Thursday and Friday
due to pulses from a northerly swell. The increasing winds and
seas will again cause the risk of rip currents to become high
Thu night and into Friday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 87 73 87 / 30 30 20 20
STT 74 85 73 82 / 40 40 20 20

&&

[JDawg512]

Didn't someone used to post weather discussions from Panama or one of the other central American countries? I'd like to see some of those.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
427 AM AST Thu Feb 23 2017

.SYNOPSIS...Mid to upper level high pressure ridge will build overhead and
remain in place through Friday, then gradually weaken and shift eastward
on Saturday and Sunday as a polar trough will move across the western
Atlantic. Surface high pressure will continue to build and spread eastward
into the north central Atlantic by Friday as an area of low pressure
and associated cold front will enter the southwest Atlantic today while
lifting east northeast across the west Atlantic. This overall pattern
will cause the local winds to become more easterly today then southeasterly
by Friday as the surface high becomes reinforced across the north central
and northeast Atlantic.

&&

.DISCUSSION...The prevailing northeast winds will continue to
transport patches of shallow low level moisture and occasional
showers to the regional waters and portions of the north and east
coastal sections of the islands during the rest of the morning
hours. By late morning cloudiness and shower activity should diminish
resulting in mostly sunny fair weather skies. During the afternoon
hours, expect the prevailing winds to become more southeasterly
and gradually increase. This along with local and diurnal effect
will lead to increasing cloudiness and isolated to scattered
shower development across parts of the central and northwest
sections of Puerto Rico as well as around parts of the San juan
metro area. For the rest of the islands, expect limited shower
activity with only a few quick quick passing showers in isolated
spots as mostly sunny skies should prevail during the day.

On Friday and into the weekend similar weather conditions expected with
brief passing early morning showers forecast to affect mainly the east
coastal sections of the islands. This will be followed by mostly isolated
afternoon showers across portions of the northern half of Puerto Rico.
Mostly fair weather skies expected for the USVI. Under a prevailing
southeast low level wind flow on Friday and Saturday, expect slightly
warmer daytime high temperature along the north half of Puerto Rico
and the San Juan metro area.

By Sunday and Monday, the formation of a weak prefrontal trough will
create sufficient low level moisture convergence across the region
to increase chances of early morning and afternoon convection mainly
over parts of the interior sections of Puerto Rico. By Tuesday of
next week ...the Atlantic surface high is forecast to build once
again north of the region and consequently tighten the local pressure
gradient. This in turn will increase the east to northeast trade winds...
which will be also be supported by increasing subsidence aloft and a
gradual drying trend across the region once again.


&&

.AVIATION...Mostly VFR conditions expected across the local flying
area for the next 24 hours. However ISOLD-SCT SHRA expected in
the vicinity of most of the terminals this morning except for
TJMZ. Passing SHRA ovr the coastal waters and en route between
islands til 23/14z. Few tops nr FL220. Low level winds are
expected to become more from the E to ESE after 23/12Z. ISOLD to
SCT SHRA is expected this afternoon, with VCSH possible across
the local terminals through the rest of the day.

&&

.MARINE...The wave watch model guidance continued to suggest
building seas across the local Atlantic water during the day.
Recent data from buoy 41043 showed seas now up to 7 feet in the
past few hours. Therefore small craft advisory will go into effect
for the Atlantic outer waters from 23/18Z. Small craft operators
should exercise caution across the rest of the Atlantic waters and
local passages. Winds are also expected to increase and become
more east to southeast today and through Friday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 73 87 74 / 20 20 20 10
STT 85 73 82 74 / 30 20 20 20

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
207 PM AST Thu Feb 23 2017

.SYNOPSIS...
A mid-upper level ridge is forecast to build from the west over
the local region through the end of the work week. An upper level
trough could weaken this ridge as it swing across the Western
Atlantic during the weekend. At the surface, a low pressure and
associated frontal boundary, near Eastern U.S., will continue to
push a surface high pressure into the Central Atlantic. This
overall surface pattern will cause the local winds to become from
the south during the weekend.

&&

.DISCUSSION...
A surge of tropical moisture moved over the region today. This
surface advection produced passing showers across the
municipalities of Eastern Puerto Rico and the U.S. Virgin Islands.
Although a southerly wind flow prevailed across the region, the
cloudiness damped the local maximum temperatures this afternoon.
For the rest of the afternoon hours, afternoon convection is
expected along and to the north of the Cordillera Central,
including San Juan Metro Area and Northwest Puerto Rico. Under
the southerly wind flow quick passing showers cannot be ruled out
across the southern sections of Puerto Rico and downwind from the
U.S. Virgin Islands.

A seasonable weather pattern will continue to prevail across the
local islands through early next week under a mid level ridge and
near normal precipitable water. A southeasterly wind flow will
continue through the weekend as a surface low and associated front
move across the Western Atlantic ocean and a surface high north
of the area shifts further east.

&&

.AVIATION...
Mostly VFR conds expected at all TAF sites with brief
MVFR conds possible in and around JMZ/JBQ due to SHRA development
through 22z. Light passing showers still possible at IST/NCM as well
as JSJ through at least mid afternoon. SE winds will continue 10-15
knots with some sea breeze variations but becoming light and
variable overnight.

&&

.MARINE...
Seas are expected to increase across the Atlantic Waters,
therefore a small craft advisory is in effect for the Offshore
waters through at least Saturday. Mariners can expect seas up to 5
ft increasing at around 6 ft across the Atlantic Nearshore water
and Caribbean passages tonight. Beach goers should exercise
caution from the Northwest to Northeast coastline of Puerto Rico,
Culebra and Northern U.S. Virgin Islands due to a high risk of rip
current late this afternoon through at least tomorrow.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 87 74 87 / 20 20 10 20
STT 74 83 75 83 / 20 20 20 20

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
509 AM AST Fri Feb 24 2017

.SYNOPSIS...Low pressure system and associated cold front moving
across the western Atlantic and high pressure anchored across the
north central Atlantic will continue to induce a south to southeast
wind flow across the region through at least Saturday. Mid to upper
level ridge will continue to gradually erode aloft today through
Saturday as a polar trough will move across the west Atlantic.

&&

.DISCUSSION...The prevailing winds are expected to remain from the
south to southeast today with a gradual decrease in moisture advection
during the rest of the day and into the weekend. However patches of
shallow low to mid level moisture and a few showers will move across
the regional waters and affect portions of the islands during the
rest of the morning hours. Thereafter mostly sunny skies and fair
weather expected with only a few afternoon showers possible mainly
along and near the north coastal sections of Puerto rico as well
as over portions of the northern Virgin islands. Shower activity
will be limited today as an overall drying trend is expected.


For Saturday...mostly fair weather skies expected under a prevailing
light to moderate south to southeast wind flow. Slightly warmer afternoon
high temperatures are forecast for today and Saturday along the northern
half of PR and around the San Juan metro area, as lesser cloud cover
is expected. On Sunday and into early next week, winds are to become
more easterly one again and increase as high pressure ridge will build
north and west of the region once again. By then, expect a slight increase
in passing trade wind low level clouds and showers especially during
the late evening and early morning hours. Shower activity during the
day should however be limited and of short durations due to the increasing
trade winds and strengthening cap inversion aloft. So far no significant
weather feature in sight for the next several days.

&&

.AVIATION...Mostly VFR conditions expected across the local flying
area with VCSH possible across the Leewards and USVI taf sites due
to small areas of low level moisture embedded in the trades, moving
across the region until 24/15Z. Southeast winds will continue light
and variable until 24/14Z, increasing to 10-15 knots after 24/14Z
with sea breeze variations. Mountain obscurations likely until
24/17Z.

&&

.MARINE...Northerly swell continued to arrive across the local
Atlantic waters and passages is still expected to peak this
morning. Buoy 41043 suggests offshore Seas now near 9 feet and
between 11-12 secs while the near shore buoys suggest Seas near 6
feet around 11 secs. Small craft advisories are in effect for the
Atlantic waters and local passages. Small craft should exercise
caution elsewhere except for the near shore coastal waters of
west and south Puerto Rico. There is a high risk of rip currents
for the Northwest through northeast coastlines of PR as well as
Culebra and the northern U.S Virgin Islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 73 86 75 / 20 0 30 20
STT 82 72 84 73 / 30 10 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
206 PM AST Fri Feb 24 2017

.SYNOPSIS...
A surface low pressure and associated frontal boundary and a high
pressure system will continue to induce a southerly wind flow
across the local islands. In addition, a mid level high pressure
will continue over the region at least until the upcoming week.
Under the prevailing weather pattern, expect warmer than normal
temperatures with limited shower activity at least until Saturday.

&&

.DISCUSSION...
A southerly wind flow produced warmer than normal temperatures
across Puerto Rico, with coastal maximum temperatures in the upper
80s to low 90s mainly across the northern half portion of Puerto
Rico. However, maximum temperatures across the U.S. Virgin Islands
continues around the mid 80s. The Doppler Radar detected little
to no shower activity across the islands today, with just a few
passing showers across the windward sections. However, the
interior and northern half portion of Puerto Rico can expect
afternoon convection at least until around the evening hours. Some
showers are also possible downwind from the northern U.S. Virgin
Islands the rest of this afternoon.

This weather pattern is expected to continue at least until
Saturday with warmer than normal temperatures and limited shower
activity. By early next week, a prefrontal trough and low level
convergence will increase the frequency of trade wind showers
across the local islands. As the surface high pressure builds
north of the region, trade wind are expected to increase locally
by the first part of the upcoming week.

&&

.AVIATION...
Mostly VFR conditions expected across the local flying area with
VCSH possible across the Leewards and USVI taf sites due to small
areas of low level moisture embedded in the trades, moving across
the region until 24/15Z. Southeast winds will continue light and
variable until 24/14Z, increasing to 10-15 knots after 24/14Z with
sea breeze variations. Mountain obscurations likely until 24/17Z.

&&

.MARINE...
Hazardous seas and dangerous breaking waves are expected across
the Atlantic shoreline of Puerto Rico, Culebra and the U.S. Virgin
Islands due to a northerly swell. Mariners can expect seas between
6 and 8 feet across the Atlantic Waters and Caribbean Passages.
This northerly swell will produce breaking wave heights between
8-10 feet. Seas are expected to slowly subside overnight. In
addition, beach goers should exercise caution due to a high risk
of rip current. Therefore, a High Rip Current Risk and a High
Surf Advisory are in effect along the Atlantic shorelines of
Puerto Rico, Culebra and northern USVI. Also, a Small Craft
Advisory is in effect for the Atlantic Waters and Caribbean
Passages.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 86 75 84 / 0 30 20 20
STT 72 84 73 85 / 10 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
418 AM AST Sat Feb 25 2017

.SYNOPSIS...A surface low pressure and associated frontal boundary
across the western Atlantic in combination with a surface high
pressure across the central Atlantic will continue to produce a
southeasterly wind flow across the region until at least Sunday. A
strong surface high pressure will move over the southwestern
Atlantic on Sunday. As this happens, the local wind is expected to
shift from the east on Sunday and from the East to east-northeast
on Monday.

&&

.DISCUSSION...Under a southeast wind flow, Doppler weather radar
detected isolated showers moving northwestward across the U.S.
Virgin Islands and eastern sections of Puerto Rico overnight and
early this morning. Under an stable weather pattern, only small
patches of moisture associated with the southeasterly wind flow
are expected to affect the eastern and southeastern sections of
Puerto Rico during the rest of the morning hours, but mostly sunny
skies are expected across most of the region. The limited moisture
in combination with daytime heating, sea breeze convergence and
other local effect are still expected to produce some cloudiness
and showers across interior and northwest Puerto Rico this
afternoon, but not widespread or significant precipitation is
expected. Under an east southeast low level wind flow, warmer
than normal temperatures are expected this afternoon mostly across
the northern coastal areas of Puerto Rico.

As the low pressure center an associated frontal boundary moves
northeastward toward the northwest Atlantic, a strong surface high
pressure is expected to move across the southwestern Atlantic.
This feature will induce an easterly low level wind flow across
the region on Sunday and an east to east-northeast wind flow by
Monday. An increase in wind speed is also expected as the surface
high pressure strengthens north of the region. Dry and generally
stable conditions are expected to continue over the region today
and Sunday. By early next week, a prefrontal trough will move back
across the region, increasing the frequency of trade wind showers
across the local islands.

&&

.AVIATION...VFR conds at all TAF sites through the fcst prd. Few
clds FL025..FL060...SKC abv. Isold -SHRA/SHRA. Prevailing east to
southeast wind flow at 10 knots or less except for local sea breeze
variations along the coastal areas. Wnds fm se 5-15 kts blo FL200...
bcmg fm SW to W and incr w/ht abv. No sig operational or wx impact
attm.

&&

.MARINE...Mariners can expect seas between 5 and 7 feet across
the offshore Atlantic Waters early this morning. Seas are expected
to decrease to 4 to 6 feet by mid morning and will continue to
slowly subside today. Beach goers should exercise caution due to a
high risk of rip currents for the northwest to northeast facing
beaches of Puerto Rico and for the northern facing beaches of
Culebra and the northern USVI. Small Craft Advisory is in effect
until early this morning for the offshore Atlantic waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 74 85 74 / 20 20 20 40
STT 83 73 85 74 / 20 20 20 40

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
204 PM AST Sat Feb 25 2017

.SYNOPSIS...Upper level trough is moving across the region today...
however mid levels continues dry and stable. As a result...shallow
convection if any will develop later this afternoon across the
north coastal sections of Puerto Rico. Although...below normal
moisture will prevail the rest of the weekend...passing showers
will reach the local islands at times. Then...high pressure builds
over the Central Atlantic pushing several bands of moisture
across the U.S. Virgin Islands and Puerto Rico next week.

&&

.DISCUSSION...An area of low level moisture moved over the U.S.
Virgin Islands...Culebra and Vieques this morning. As a result...
cloudy skies have prevailed over Culebra...Vieques and eastern
Puerto Rico today. A relatively dry and stable conditions were
observed elsewhere. Morning sounding indicated moisture level
below normal and strong subsidence cap at 800mb. The rest of today...
sea breeze convergence will likely induce some showers over the
northern half of Puerto Rico. Conditions will remain fairly stable
the rest of the wek. The winds shift from the east on Sunday...
focusing the afternoon showers over portions of the West Interior
and Western Puerto Rico.

An easterly pertubation will reach the Northeast Caribbean between
Monday and Tuesday...increasing the potential for showers across
the USVI and PR. At the same...surface high pressure is forecast
to build over the Central/Eastern Atlantic resulting in fresh
trade winds over the local area. As a result...a trade wind pattern
will establish across the local islands most of next week. Patches
of low level moisture embedded in the trade winds will bring
passing showers across the local islands from time to time.

&&

.AVIATION...VFR conds at all TAF sites through the fcst prd. Few
clds FL025..FL060...SKC abv. Isold -SHRA/SHRA. Prevailing east to
southeast wind flow at 10 knots or less except for local sea breeze
variations along the coastal areas. Wnds fm se 5-15 kts blo FL200...
bcmg fm SW to W and incr w/ht abv. No sig operational or wx impact
attm.

&&

.MARINE...Marine conditions will gradually improve through Monday
Morning. Surface high pressure will build over the Central/Eastern
Atlantic resulting fresh winds across the region. This will lead
to choppy seas across the local waters from late Monday through
the end of next week. Seas are forecast to build up to 8 feet
across the offshore waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 85 74 85 / 10 20 40 40
STT 73 85 74 86 / 20 20 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
408 AM AST Sun Feb 26 2017

.SYNOPSIS...A surface low pressure system will continue to move
northeastward across the northwest Atlantic today. A strong
surface high pressure will move over the southwestern Atlantic
pushing the associated frontal boundary eastward. This high
pressure will maintain the local winds mostly from the east this
morning and from the east to east-northeast this afternoon and
Monday. As the surface high pressure moves toward the central
Atlantic, patches of low level moisture embedded in the northeast
trades are expected to moves across the region early in the week
increasing the chances of showers.


&&

.DISCUSSION...Under an easterly wind flow, Doppler weather radar
detected isolated showers moving westward across the U.S. Virgin
Islands and eastern sections of Puerto Rico overnight and early
this morning. Not significant precipitation was observed
elsewhere across the region so far this morning. Under a relative
stable weather pattern, only small patches of moisture associated
with the easterly wind flow are expected to affect the eastern and
sections of Puerto Rico during the rest of the morning hours, but
mostly sunny skies are expected across most of the region. The
limited moisture in combination with daytime heating, sea breeze
convergence and other local effect are still expected to produce
some cloudiness and showers across interior and western Puerto
Rico this afternoon.


An increase in wind speed is expected early in the week, as the
surface high pressure strengthens over the central Atlantic just
north of the region. A generally dry and stable weather conditions
are expected to prevail over the region today. By early next
week, areas of moisture embedded in the trades will move across
the region from time to time, increasing the frequency of trade
wind showers across the local islands and surrounding waters.

&&

.AVIATION...VFR conds will prevail across all terminals through the
forecast period. Few passing showers will affect the coastal waters
N and E of PR and en route btw PR and the Northern Leeward islands
til 26/12Z. Sf winds light and variable...bcmg fm E-NE aft 26/14Z...
incr 10-15 kts aft 26/13z with sea breeze variations. L/lvl wnds fm
E-NE 5-15 kts Blo FL100...bcm fm S-SW up to FL250...then fm N and
incr w/ht abv. Mostly SKC abv FL100. No sig operational impacts ovr
local flying area or at local TAF sites attm.

&&

.MARINE...Seas have diminished near 5 feet across the offshore
Atlantic waters. Seas are expected to increase once again Monday
night into Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 85 74 / 20 20 20 40
STT 83 73 85 74 / 20 20 20 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
154 PM AST Sun Feb 26 2017

.SYNOPSIS...Mid-upper level ridge will hold through at least
midweek. Surface high pressure will exit the Eastern US on Monday
tightening the pressure gradient across the region. The strong
high pressure will bring breezy to windy conditions across Puerto
Rico and the U.S. Virgin Islands most of the week as moves eastward
through the North Atlantic.

&&

.DISCUSSION...A relatively stable conditions have been observed
across the local islands today. Morning TJSJ sounding indicated
normal moisture levels and strong subsidence cap around 775mb.
Satellite imagery is showing sea breeze convergence along the
Interior and West Puerto Rico. This convergence will likely result
in scattered showers across these areas later this afternoon.
However...no significant rainfall accumulations are expected with
this activity as mid-upper level ridge will inhibit the vertical
development of the showers.

The next band of moisture will reach the USVI and eastern PR
after 27/06Z. This band of moisture is associated with an easterly
pertubation that will enhance the moisture convergence across the
islands early Monday. In the wake of the low level pertubation...
a patch of drier air will spread over the USVI/PR late Monday
afternoon and evening. This drier air mass will be short-lived as
another area of moisture will move over the islands on Tuesday.

A trade wind pattern will persist most of the week as fresh to
strong trades will bring passing showers at times. All in all...
expect breezy conditions with a mixture of sunshine and clouds as
well as scattered showers from time to time dominating the local
islands for the next several days.

&&

.AVIATION...VFR conds expected through the fcst period. SHRA and
Clouds are expected across the interior and west PR, as a result
SHRA can affect TJMZ btwn 26/18-22z. Then showers en route btw PR
and the Northern Leeward islands expected btwn 27/00-12Z. The
frequency of showers is possible across E-PR and USVI terminals
btwn 27/06-12z. Low levels E-NE winds at 15 to 25 knots.

&&

.MARINE...Strong surface high pressure will move north of the
islands over the next few days increasing the trade winds around
20 kts. Fresh to strong winds will lead to choppy seas across the
local waters most of next week. Seas are forecast to build up to
8 feet across the offshore waters. Seas of 5-7 feet are expected
across the near-shore wates. Small Craft Advisories will likely
begin tonight and continue through the end of the work week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 84 74 85 / 50 50 30 30
STT 74 85 74 85 / 40 40 30 30