Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
130 PM AST TUE MAY 17 2016

.SYNOPSIS...Ridge aloft will continue as the dominant weather
feature during the next few days. This feature will then erode as
trofiness establishes across the area late this week and into the
upcoming week. A broad surface high pressure across the Central
Atlantic will continue to maintain moderate to fresh east
southeast winds.

&&

.DISCUSSION...Skies were mostly sunny to partly cloudy during
the morning hours, becoming variably cloudy in the afternoon.
Light showers were observed across the USVI and the eastern third
of Puerto Rico during the morning hours with a few locally
induced afternoon showers across the western interior of Puerto
Rico so far. The maximum temperature ranged from the mid to the
upper 80s across the coastal areas. Winds over land were mainly
from the east southeast at 10 to 20 mph with higher gusts and sea
breeze variations.

A generally fair and mainly stable weather pattern will continue
to prevail across the local islands as ridge aloft and its
associated subsidence cap as well as below normal precipitable
water prevail across the forecast area. However, passing showers
embedded in the moderate to fresh trade wind flow are still
possible across the USVI and the eastern third of Puerto Rico
during the morning and evening hours, with limited afternoon
convection expected across Northwest Puerto Rico on Wednesday. As
trofiness establishes across Northeast Caribbean, moisture is then
expected to pool across the forecast area Thursday through Sunday.
This will result in showers and thunderstorms developing over and
north of the Cordillera Central each day during the afternoon
hours.

A broad mid to upper level trough will establish across the Western
Atlantic and into the Caribbean early next week with additional
moisture reaching the area from the south. As a result, areal
coverage and intensity of showers and thunderstorms are expected
to increase early next week.

&&

.AVIATION...Brief MVFR conds and mtn top obscr posible ovr Western
PR aft 17/17z. Some of these SHRA/TSRA will continue to affect TJMZ
and TJBQ thru 22Z. SHRA will continue to affect the eastern half of
the region. SFC winds will prevail E to ESE at 15-20 kts with gusts
between 20-25 kts.

&&

.MARINE...Moderate to locally fresh trade winds will continue
to prevail across the local waters with seas at 4-5 feet. Seas
expected to slightly increase tonight and Wednesday. Small
crafts should continue to exercise caution.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 88 78 89 / 20 20 30 30
STT 80 89 78 86 / 30 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
530 AM AST WED MAY 18 2016

.SYNOPSIS....Mid to upper level ridge overhead will hold at least
Until Thursday then gradually erode by Friday and into weekend as
short wave trough is forecast to enter and move across the West
and Central Atlantic. This will be followed by a long wave trough
which Will move across the Western Atlantic and then become amplified
over the Southwest Atlantic. In the low levels...Atlantic High will
remain anchored across the Central and East Atlantic to maintain
a moderate to fairly strong east to southeast trade wind flow
across The region. Surface high pressure ridge is to slowly shift
eastward over the next few days allowing for weakly induced easterly
pertubations to move Across the area from time to time.

&&

.DISCUSSION...Few trade wind showers developed across the coastal
waters and moved inland across portions of Puerto Rico and the
adjacent islands during the overnight hours. Expect skies to become
Mostly sunny skies by late morning across most of the islands. During
the afternoon...mostly isolated showers expected across most of the
islands except for the west and northwest sections of Puerto Rico
where scattered shower and isolated thunderstorms will remain possible.
Some showers although of short duration may be locally heavy at times.

Similar weather pattern expected through Thursday with a better
chance for showers and isolated thunderstorm activity on Friday
and Saturday as a surge of moisture in the easterly trades will
move across the region. This in combination with an upper level
short wave trough forecast to move across the region...may give
way To enhanced convection and better chance for thunderstorm activity.
In addition...winds are forecast to become more southerly by the end
of the work week and into the weekend leading to warmer sfc temps
across the islands.

By late sunday and into the early part of the following week...a
long wave trough is to move across the Western Atlantic and the low
level wind flow is to become more southerly. Most recent model guidance
suggests...the combination of a moist southerly wind flow and the
approaching the upper trough from the west will bring an even
wetter and unstable pattern to the region. This will increase the
chance thunderstorm activity and therefore lead to more active
weather conditions. This outlook is however in the long term so
will continue to monitor and see how this pattern unfolds.

&&

.AVIATION...Until 18/16Z...ISOLD to SCT brief passing SHRA may cause
VCSH at the local terminals except TJBQ and TJMZ. After 18/16Z...SHRA
and possible a couple of TSRA is expected to develop across western
PR...likely causing VCSH/VCTS at TJMZ and TJBQ with possible SHRA
at TJBQ...which may briefly cause MVFR conditions. SFC winds from
the east at around 10 kt until 18/14Z...increasing to 15kt and gusting
to around 20kt after 18/14Z across the local terminals. Sea breeze
variations expected at TJMZ and TJPS.

&&

.MARINE...Winds will continue to be moderate to locally fresh.
Seas will continue around 5 to 6 feet in the outer waters and local
passages...and mainly 3 to 4 feet in near shore waters. Easterly
trade winds will be 15 to 20 knots creating choppy seas. For this
reason small craft operators should exercise caution. Recent
models guidance suggest seas to remain less than 7 feet during
the next 7 days...so small craft advisories are not anticipated at
this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 88 78 / 30 30 30 40
STT 88 78 87 78 / 20 30 30 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
101 PM AST WED MAY 18 2016

.SYNOPSIS...Upper level perturbations will move across the
forecast area Thursday through the upcoming weekend, as ridge
pattern aloft continues to weaken. Broad surface high pressure
across the Central Atlantic will continue to promote moderate
to fresh east southeast winds the next several days.

&&

.DISCUSSION...Skies were mostly sunny to partly cloudy during the
morning hours, becoming variably cloudy in the afternoon. Light
showers were observed across the USVI and the eastern third of
Puerto Rico during the morning hours with a few locally induced
afternoon showers so far.

Under weakening ridge aloft, upper level perturbations will begin
to move across the area Thursday through at least the upcoming
weekend. This will allow moisture to pool across the area.
Although enough moisture is expected on Thursday, there is a lack
in the upper level dynamics. Therefore, expect typical weather
pattern with locally induced showers and thunderstorms focused
across the northwest quadrant of Puerto Rico in the afternoon.

Shower activity will be enhanced Friday and into the weekend, as
a more robust divergent pattern is expected to prevail. This will
result in showers and thunderstorms developing over and north of
the Cordillera Central each day during the afternoon hours. A
broad mid to upper level trough will then establish across the
Western Atlantic and into the Caribbean early next week with
moisture advection from the south. As a result, areal coverage and
intensity of showers and thunderstorms are expected to increase
early the next week.

&&

.AVIATION...VFR conds expected today with SHRA/TSRA possible across
TJBQ/TJMZ this afternoon. However...at this time...no TEMPO was
included. After 18/23z...occasional passing SHRA expected mainly
in the VCTY of TJSJ/TJPS/TIST/TNCM/TKPK...without any significant
impact to operations. TJSJ sounding data showed E-ESE winds btwn
8-24 KT. Gusty winds expected in/near SHRA/TSRA. Easterly winds
below 10 knots expected aft 18/23z.

&&

.MARINE...Winds will continue to be moderate to locally fresh.
Seas will continue around 5 to 6 feet in the outer waters and
local passages...and mainly 3 to 4 feet in near shore waters.
Easterly trade winds will be 15 to 20 knots. Winds are forecast
to diminish somewhat and become east southeast by Friday and into
the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 90 78 88 / 30 30 40 40
STT 78 89 78 86 / 30 30 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
429 AM AST THU MAY 19 2016

.SYNOPSIS...Mid to upper level ridge will gradually erode overnight
through Friday and into weekend as short wave trough will move across
the West and Central Atlantic. This will be followed by a long wave
trough forecast to become amplified over the Southwest Atlantic.
In the low levels...Strong Atlantic High will remain in place across
the Central and East Atlantic to maintain a moderate to strong east
to southeast trade winds. Surface high pressure ridge is forecast
to slowly shift eastward through the upcoming weekend as a cold front
and area of low pressure will move across the Northwest Atlantic.
This pattern will allow weakly induced easterly pertubations to move
Across the region area from time to time.

&&

.DISCUSSION...Trade wind showers continued to develop across the
coastal waters and move inland across portions of eastern Puerto
Rico and a few of the adjacent islands during the overnight hours.
Cloud cover and shower activity will diminish by late morning becoming
mostly sunny across most of the islands. However...locally and
diurnally induced shower activity is expected across some of the
islands... particularly over the west and northwest sections of
Puerto Rico where isolated thunderstorms will remain possible.
The Showers activity although of short duration may be locally
heavy in isolated spots.

By Friday and into the weekend... still expect a better chance for
showers and isolated thunderstorms as a surge of moisture in the
easterly trades will move across the region. This in combination
with an upper level short wave trough...will give way to enhanced
convection and increase the chance for thunderstorm activity across
the islands and coastal waters. The migration of the Atlantic high
to the east will also increase the low level southerly flow leading
to warmer temps across the islands.

By late Sunday and into the early part of the following week...the
previously mentioned long wave trough supported by a developing area
of low pressure at the surface across the Western Atlantic will aid
in increasing the low level convergence and southerly flow. Latest
model guidance continue to suggest...the combination of the southerly
wind flow and the approaching the upper trough will bring a moist
and unstable pattern to the region. Therefore based on this guidance
and the overall weather pattern...still looking for the most active
weather conditions late Sunday through Monday of next week.

&&

.AVIATION...ISOLD-SCT brief SHRA will continue to affect the
leeward islands...USVI...TJSJ and TJPS taf sites with VCSH until
19/16Z. Thereafter...SHRA is expected to develop across Western
PR...causing VCSH and possible VCTS at TJMZ and TJBQ with possible
SHRA/TSRA at the TJBQ terminal...which may briefly cause MVFR
conditions. SFC winds will continue from the east at around 10 kt
until 19/14Z...increasing to 15kt gusting to around 20kt after
19/14Z across the local terminals. Sea breeze variations expected
at TJMZ and TJPS.

&&

.MARINE...Seas will continue up to 6 feet mainly over the Atlantic...
local passages and offshore waters due to winds of 15 to 20 knots.
Seas of 5 feet or less elsewhere. Small craft operators should
exercise caution due to the choppy conditions.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 90 78 / 30 30 30 40
STT 88 78 89 78 / 20 30 30 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
201 PM AST THU MAY 19 2016

.SYNOPSIS...
Upper to Mid level...a ridge aloft will continue to weaken as an
upper level perturbation moves over the region by Friday and into
the weekend. A mid-upper level trough is forecast to move across
the islands by early next week. At the surface...another surge of
moisture is expected to reach the island on Friday. A surface high
pressure centered over the North Central Atlantic will dominate
the water conditions at this levels. This high pressure is
forecast to slowly drift eastward as a low pressure system with it
associated front moves across the Western Atlantic.

&&

.DISCUSSION...
The skies prevailed mostly sunny across the islands of Puerto Rico
and the U.S. Virgin Islands this morning. Then satellite imagery
showed partly to mostly cloudy skies early in the afternoon.
Showers developed over the cordillera central and across the
northern slopes late in the morning into the early afternoon. In
addition...some showers formed downwind from the U.S. Virgin
Islands. Then...the local effects and the diurnal heating combined
with the available moisture to enhance afternoon convection
across the interior and western sections of Puerto Rico.
Also...thunderstorms are possible over these sections. This
activity is expected to continue until evening hours.

By Friday...an upper level perturbation is expected to combined
with a surge of moisture to enhance the formation of showers
across the islands. The activity is expected across the eastern
windward sections during the morning hours...followed by afternoon
convection across the interior and western sections of Puerto
Rico. However...the San Juan Metropolitan area as well as the U.S.
Virgin Islands can expected showers during this period. This
weather pattern is expected to continue during the weekend.

Model guidance is forecasting the arrival of a broad mid to upper
level trough across the Western Atlantic and into the Caribbean.
If this pattern is correct...an increase in areal coverage and
intensity of showers and thunderstorm is also possible for the
upcoming week.

&&

.AVIATION...
Brief MVFR conds in TSRA/SHRA will remain possible at
JMZ/JBQ through at least 19/22z, with VCSH at JSJ/IST. VFR conds
are then expected at all TAF sites with passing showers possible
at Leeward and USVI Terminals as well as JSJ overnight. ESE winds
10 to 15 knots with higher gusts and sea breeze variations
expected till 19/22z, becoming at 5 to 10 knots overnight.

&&

.MARINE...
Mariners can expect moderate to locally fresh winds with seas at 2
to 4 feet nearshore and between 4 and 6 feet across the offshore
waters and Caribbean Passages. Therefore...small craft operators
should exercise caution across the Atlantic Waters and Caribbean
Passages.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 78 90 / 30 40 30 30
STT 78 87 78 87 / 50 50 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
526 AM AST FRI MAY 20 2016

.SYNOPSIS...Short wave trough will move aloft from the west during
the weekend. This will be followed by a deep layered upper trough
across the western Atlantic by early next week. A strong surface
high pressure will meander across the north central Atlantic
through late next week...maintaining a moderate to fresh east to
southeast trade wind flow. An induced surface trough is expected
to develop just north of the forecast area by early next week.

&&

.DISCUSSION...Trade wind showers continued across the local
waters with a few of them reaching portions of the USVI and
coastal areas of eastern PR during the overnight hours. But
overall it was mostly clear to partly cloudy skies over land
areas. For this afternoon...upper level short wave trough will
enhance diurnal convection across the interior and nw quadrant of
PR. This will result in scattered to numerous showers at times
with isolated thunderstorms. During the weekend...as surface high
pressure shifts a little to the east...low level southerly flow
will establish across the forecast area...leading to warmer temps
across the islands.

By early next week...a deep layered trough supported by a
developing area of low pressure at the surface across the Western
Atlantic will aid in increasing the low level convergence and
southerly flow. Also...it seems likely that it will induce a
surface trough to the west and north of the area. Latest guidance
continue to suggest...that this scenario will result in a moist
and unstable weather pattern to the region. Overall...shower and
thunderstorm activity will increase each afternoon...with better
chance for widespread rain activity for late Sunday into Monday.


&&


.AVIATION...Isolated to scattered SHRA will continue to produce VCSH
across the Leewards...USVI and TJSJ taf sites thru 20/15Z. SHRA and
isolated TSRA will develop after 20/16z over interior and western PR
with mountain obscurations and brief MVFR conditions in SHRA...
across TJMZ and TJBQ. Sfc winds will remain from the east to east
southeast at 5 to 10 kt...becoming ESE 10 to 16 kt with sea breezes
aft 20/14z. winds aloft from NW at 20-30 kt above FL400 otherwise
generally less than 10 kt between FL190-400.


&&

.MARINE...Small craft operators are urged to exercise caution as
seas are still up to 6 feet across the Atlantic waters. Winds
between 15 to 20 knots are likely this afternoon across the coastal
waters of the islands. There is a moderate risk of rip currents
across many of the local beaches both in Puerto Rico and in Saint
Croix.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 89 79 / 20 30 30 20
STT 87 78 86 79 / 10 40 40 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
404 AM AST SAT MAY 21 2016

.SYNOPSIS...Upper level trough to the east of the local islands
will continue to move further east while filling today and
tonight. a broad mid to upper level trough is then expected to
build over the western Atlantic on Sunday, amplifying across
Hispaniola early in the week. This feature will remain over the
Greater Antilles...to the west of the local region most of the
week. At the surface, a high pressure, over the North Central
Atlantic, is forecast to slowly drift eastward as a low pressure
system with it associated front moves across the Western Atlantic.

&&

.DISCUSSION...Doppler weather radar indicated isolated to
scattered passing showers across eastern sections of Puerto Rico
overnight and early in the morning. Not significant precipitation
was observed elsewhere across the region. this moisture will
combine with daytime heating and local effects to induce the
development of showers and a couple of thunderstorms mostly across
northwest Puerto Rico this afternoon.

An upper level trough to the east of the region is expected to
move further east while dissipates today and tonight. Not
significant changes are expected in the present weather pattern today
and Sunday. latest model guidance suggests that an upper level
trough will move over the western atlantic and eastern United
States seaboard on Sunday. This trough is then expected to amplify
just over the Greater Antilles early in the week, while
strengthens to the west of Puerto Rico. As this happens...abundant
tropical moisture will move across the local islands increasing
the instability, showers and thunderstorms development and
coverage early next week. PWAT values are expected to steadily
increase up to above 2.0 inches from Monday thru Wednesday...
slightly decreasing on Thursday and Friday and then increasing
even more by the upcoming weekend as a large area of tropical
moisture encompass the region from the southeast. We need to
closely monitor how this situation evolves over the next few days.

&&

.AVIATION...VFR prevailing. SCT SHRA over lcl waters...ern PR and
Leeward Islands with tops 11-20 kft lcl waters...up to 35 kft in the
Mona Passage. Mtn obscurations ern PR and brief pds of MVFR at
TNCM/TKPK. Aft 21/16z SHRA/TSRA dvlpg ovr interior and northwestern
PR with brief pds of MVFR conds psbl TJMZ and TJBQ. Winds alf ESE 8-
18 kt up to only FL080...bcmg Sly 10 kt FL080-110 with SW-W abv.
Winds increasing from 15-35 kt FL180-450.

&&

.MARINE...Seas up to 6 feet and winds up to 20 knots will continue
across the regional waters today and tonight. Small craft operators
are urged to exercise caution across the Atlantic waters and
Caribbean Passages. Shower and thunderstorm activity is expected
to increase across the local waters during the upcoming work week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 90 78 / 30 20 30 30
STT 86 79 87 78 / 40 20 40 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
216 PM AST SAT MAY 21 2016

.SYNOPSIS...MID TO UPPER LEVEL TROUGH EAST OF THE REGION WILL
CONTINUE TO LIFT NORTHEAST OVER THE NEXT FEW DAYS. THEN...A BROAD
POLAR LOW WILL AMPLIFY OVER THE WESTERN ATLANTIC EARLY NEXT WEEK...
INDUCING A MID TO UPPER LEVEL TROUGH OVER CUBA AND BAHAMAS. THIS
TROUGH ALOFT WILL DOMINATE THE WEATHER CONDITIONS ACROSS THE LOCAL
ISLANDS...FAVORING THE MOISTURE TRANSPORT FROM THE CARIBBEAN WATERS.

&&

.DISCUSSION...SOUTHEASTERLY FLOW HAS RESULTED IN SHOWERS ACROSS
THE PORTIONS OF NORTH AND NORTHWEST PUERTO RICO. THE HEAVIEST
RAINFALL STILL EXPECTED ACROSS PORTIONS OF NORTHWEST PR WHERE A
FEW THUNDERSTORMS ARE STILL EXPECTED LATER THIS AFTERNOON. ON
SUNDAY...CONDITIONS WILL BE SIMILAR WITH SHOWERS DEVELOPING OVER
NORTHWEST PR AND MAX TEMPS RANGING AROUND 85F-90F ACROSS MOST OF
THE LOCAL ISLANDS.

A WETTER PATTERN IS EXPECTED EARLY NEXT WEEK AS A POTENT UPPER
TOUGH AMPLIFIES OVER THE WESTERN ATLANTIC AND DEEPER MOISTURE WILL
SURGE OVER THE REGION FROM THE CARIBBEAN. AT THIS TIME...THE BEST
DYNAMICS AND MOISTURE ADVECTION APPEARS TO BE OVER THE HISPANOLA...
WHERE OPERATIONAL MODELS SUGGEST THE BEST RAINFALL AMOUNTS. HOWEVER...
THE PROXIMITY OF THE MID-UPPER TROUGH WILL ENHANCE THE CONVECTIVE
INSTABILITY ACROSS THE ISLANDS...RESULTING IN PERIODS OF HEAVY RAINFALL
AT TIMES. ALTHOUGH...STRONG CONVECTION CAN NOT RULED OUT...A DENSE
MID-UPPER LEVEL CLOUDINESS WILL LIMIT THE COVERAGE OF THE SHOWERS.
ANY BREAKS IN THE CLOUD COVER NEXT WEEK WILL Likely TRIGGER
SHOWERS AND THUNDERSTORMS EACH AFTERNOON. OTHERWISE ACTIVITY WILL
BE LIMITED TO LIGHT RAIN SHOWERS ACROSS USVI AND EAST PUERTO RICO.

THE SECOND PART OF NEXT WEEK...STILL LOOK UNSTABLE AND MOIST ACROSS
THE NORTHEAST CARIBBEAN AS UPPER TROUGH WILL PREVAIL WEST OF THE AREA.

&&

.AVIATION...VFR CONDS EXPECTED ACROSS THE MOST OF THE TAF SITES
EXCEPT TJBQ WHERE A FEW TSRA MAY DEVELOP LATER IN THIS AFTERNOON.
SE WINDS OF 10-15 KT EXPECTED BELOW FL050.

&&

.MARINE...MARINE CONDS WILL REMAIN RELATIVELY TRANQUIL OVER THE
NEXT 5-7 DAYS WITH WINDS OF 10-15 KT AND SEAS OF 3-5 FT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 78 90 / 30 40 30 50
STT 79 87 78 86 / 30 40 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
459 AM AST SUN MAY 22 2016

.SYNOPSIS...Upper level trough to the east of the local islands
will continue to move further to the northeast while filling
today and tonight. a broad upper level trough is then expected to
move over the western Atlantic today, amplifying across
Hispaniola early in the week. This feature is expected to remain
over the Greater Antilles...to the west of the local islands most
of the week...allowing more moisture transport over the local
islands. At the surface, a high pressure, over the North Central
Atlantic is forecast to drift rapidly eastward as a low pressure
system with it associated front moves across the Western Atlantic.

&&

.DISCUSSION...Doppler weather radar indicated only isolated to
scattered showers mostly across the surrounding waters overnight
and early this morning. however...not significant precipitation
was observed over land areas. The low level wind flow is expected
to become more from the southeast today. this will result in
slightly more than normal temperatures mainly across the northern
coastal municipalities of Puerto Rico. The moisture over the
region will combine with daytime heating and local effects to
induce the development of scattered showers and a couple of
thunderstorms mostly across northwest Puerto Rico this afternoon.

An upper level trough to the east of the region is expected to
move further northeast while filling today. Not significant
changes are expected in the present weather pattern today and
tonight. Latest model guidance suggests that an upper level
trough will move over the western atlantic and eastern United
States seaboard today. This trough is then expected to amplify
just over the Greater Antilles early in the week, while
strengthens to the west of Puerto Rico. As this happens...abundant
tropical moisture will move across the local islands increasing
the instability and the potential for an increase in the coverage
of showers and thunderstorms. PWAT values are expected to
steadily increase to near or above 2.0 inches from Monday thru
Friday and then increasing even more by the upcoming weekend as a
large area of tropical moisture encompass the region from the
southeast. We need to closely monitor how this situation evolves
over the next few days.

&&

.AVIATION...Sensors had been reporting MVFR cigs in TIST and
TISX till 22/0830Z but all other reporting stations have been VFR.
VFR is expected to continue until SHRA/isold TSRA devlp over
interior and western PR aft 22/16Z. Improved moisture is expected to
yield greater coverage than yesterday with mtn obscurations til aft
23/02z. Sfc winds ESE bcmg 10 to 15 kt with sea breeze influences.
Winds alf bcmg Sly 10-15 kt with height by FL100. Maximum wind W 40
knots at and abv FL370.

&&

.MARINE...Seas up to 5 feet and winds up to 20 knots will
continue across the regional waters today and tonight. Small craft
operators are urged to exercise caution across the part of the Atlantic
waters and Caribbean waters due to winds. Shower and thunderstorm
activity is expected to increase across the local waters during
the upcoming work week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 91 78 / 30 10 20 30
STT 86 80 88 78 / 40 20 20 50

&&

[HurricaneFan]

So according to the forecast Hispanola will get the most Rain from the Rain Event early this week?
How much Rain could be expected in the Northern Leeward Islands Monday and Tuesday?
And after it is toned down for latter part of the week,how much Rain can be expected on the weekend?
Thanks in Advance.

[cycloneye]

So according to the forecast Hispanola will get the most Rain from the Rain Event early this week?
How much Rain could be expected in the Northern Leeward Islands Monday and Tuesday?
And after it is toned down for latter part of the week,how much Rain can be expected on the weekend?
Thanks in Advance.

For this week not a lot of rain .25 to .75 is expected for the Northern Leewards but for next weekend thru June 2nd over 2 inches may fall. But all is subject to change so stay tuned.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
156 PM AST SUN MAY 22 2016

.SYNOPSIS...Subequatorial ridge will dominate the local weather
condtions through midweek. Then...a polar low will induce a mid
to upper level trough over cuba and bahamas...favoring the moisture
transport across the east and central caribbean later in the week.
As a result...weather pattern will likely become unstable and
moist across the local area after midweek.

&&

.DISCUSSION...Mostly sunny skies and southerly winds have resulted
in warm temperatures across the islands today. Max temperatures
have ranged between upper 80s and low 90s so far this afternoon.
Isolated showers have begun to develop across portions of Northwest
Puerto Rico early this afternoon. As generally stable conditions
are prevailing across the region...most of this shower activity
will be short-lived.

Through Midweek...Ridge aloft combined with drier air at low to
mid level will likely result in a relatively fair weather pattern
across the islands over the next few days. Some Saharan Dust will
be embedded with the drier air at mid-levels resulting in reduced
visibilities at times. Typical showers over northwest PR can not
ruled out each afternoon...but the coverage will be isolated to
scattered.

Operational models suggest a wetter pattern by the end of next
week as a mid-upper level trough develops over Cuba/Bahamas. The
impact over PR/USVI associated with this feature are still unknown
at this time. The position of the trough will determine how active
the weather will be across the local islands by the end of the
week. Stay tuned.

&&

.AVIATION...Mostly VFR conds expected during the rest of the
forecast period. SHRA possible over NW PR with mountain obscurations
over the west interior of PR. Brief MVFR conditions in SHRA
possible at TJBQ thru 22Z. Sfc winds will remain from the east to
east southeast at 5 to 15 kt.

&&

.MARINE...Marine Conds will remain similar the entire week. Winds
of 10-15 kt and seas of 3-5 will prevail across the regional waters.
No small craft advisories are anticipated through the forecast
period.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 90 79 90 / 30 30 30 40
STT 81 87 80 87 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
549 AM AST MON MAY 23 2016

.SYNOPSIS...At upper levels...A ridge of high pressure over the
anegada passage will shift east and build farther north during
the next 24 hours. A trough will dig over Cuba through mid week.
This pattern, with minor variations, will continue through mid
week next week.

At mid levels...Low pressure over the eastern United States will
cut-off over the Bahama Islands on Wednesday and continue spinning
in the area through the end of the week. High pressure over the
Central Atlantic will build west to the east coast of the United
States later this week and hold over the weekend.

At lower levels...Low pressure continues over the western
Atlantic while high pressure prevails over the central atlantic
and the northeastern Caribbean sea. High pressure will fill in
just east of Georgia overnight on Tuesday. High pressure over the
Atlantic will fade later this week. Moderate to fresh trade wind
flow from the east southeast will shift to mainly east by mid
week. Although the marine layer will be rich in moisture it will
reach to little over 5 kft this week so as to limit shower
activity.

&&

.DISCUSSION...Although 500 mb temperatures will decrease during
the week for greater instability, mid level moisture is lacking
and affects even the upper portion of the lower levels. This
explains both the limited activity yesterday and the similar
forecast today. East south east flow will continue today and will
keep high temperatures on the north coast in the upper 80s and
lower 90s with a heat index approaching 100 degrees, and even
exceeding 100 in a few places--some near the greater San Juan
metropolitan area. Convection will be limited in the area but
local rains could be heavy for one or two hours in western and
interior Puerto Rico. Models also continue to bring in higher
clouds Tuesday through Thursday that will form a fairly deep
layer. This will reduce the amount of direct sunshine and surface
heating for thunderstorms, keeping them isolated during the
afternoons later this week. The GFS continues to forecast very wet
weather at the end of the period as it has for several weeks.
Although it is possible, confidence that this very wet weather
will materialize is low. Nevertheless, precipitable water values
could exceed 2 inches by Thursday and 2.2 inches by Sunday.

&&

.AVIATION...Mostly VFR conds are expected today. Brief -RA is possible
across TJPS/TIST/TISX/TJSJ this morning. Although...VFR conditions
are expected...we cannot rule out afternoon convection, isold TSRA and
mtn obscurations across the Interior/Western sections of PR this
afternoon. In addition...showers may develop downwind from El
Yunque to affect the vicinity of TJSJ late in the morning into
early this afternoon. Sfc winds will be from the east to southeast
at 5 to 15 kts increasing at 10 to 20 kt with higher gusts after
23/13z.

&&

.MARINE...Winds and seas continue somewhat above normal in both
the Atlantic and Caribbean waters and small craft will have to
exercise caution in the local outer waters and the Mona Passage.
The wavewatch even suggests that winds could be locally strong
enough in the outer Caribbean waters for 7 foot seas on Thursday
morning. Conditions subsequently subside.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 92 78 90 78 / 10 20 20 30
STT 89 78 89 80 / 10 10 10 20

[HurricaneFan]

It looks like the Rain Event is getting delayed to Thursday according to the forecast.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
208 PM AST MON MAY 23 2016

.SYNOPSIS...Subequatorial ridge will dominate the local weather
conditions through most of the week as high amplified trough
remains over the Western Caribbean. Then...a polar low will induce
a mid to upper level trough over cuba and bahamas...favoring the
moisture transport across the central and east caribbean later in
the week. As a result...weather pattern may become more unstable
across the local area by the end of the week.

&&

.DISCUSSION...Hazy skies and southerly winds have resulted in
above normal temperatures across the islands today. Max temps
were in the lower 90s so far this afternoon. A few showers are
still possible across portions of Northwest Puerto Rico later
this afternoon. Any shower that develops later this afternoon
will shower activity will be short- lived.

Ridge aloft combined with drier air at mid level will likely
result in a generally fair weather pattern across the islands
most of the work week. Some Saharan Dust particles will continue
to affect the local islands through at at least Tuesday...diminishing
the concentrations Wednesday and Thursday. Typical showers over
northwest PR can not ruled out each afternoon...but the coverage
will be isolated to scattered through midweek. Mid to upper clouds
will stream across the islands starting on Tuesday.

GFS suggests a wetter pattern by the end of next week as a mid-
upper level trough develops over Cuba/Bahamas. However...the rest
of the operational models disagree with the GFS solution. At this
time...the location of the aforementioned of the upper trough is
still unknown at this time. Considering the persistence of the
mid-upper ridge pattern over the Eastern Caribbean...we are
leaning towards the dryer solution for the weekend and probably
next week.

&&

.AVIATION...Mostly VFR cond expected today. Brief -RA are possible
across TJPS/TIST/TISX/TJSJ this morning. Although...VFR conditions
are expected...we cannot ruled out afternoon convection and mount
obsc across the Interior/Western sections of PR this afternoon. In
addition...showers may developed downwind from El Yunque to affect
the vicinity of TJSJ late in the morning into early this afternoon.
Sfc winds will be from the east to southeast at 5 to 15 kts
increasing at 10 to 20 kt with higher gusts after 23/13z.

&&

.MARINE...Fresh winds of 15-20 kt will keep the seas around 4-6
feet through Tuesday. Winds and seas will subside sightly by
midweek as surface high pressure over the Central Atlantic
weakens. Therefore...expect moderate winds and seas of 3-5 ft
from mid to the end of the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 90 78 87 / 20 20 30 10
STT 78 89 80 88 / 10 10 20 10

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
536 AM AST TUE MAY 24 2016

.SYNOPSIS...High pressure at mid and upper levels will generate
only modest showers and possibly a few thunderstorms today and
tomorrow. Moisture increases over the weekend and low level flow
becomes more southerly.

At upper levels...A ridge extends north out of South
America and across the Anegada Passage...while a low forms north
of Cuba and a trough moves northeast toward Hispaniola today
through Thursday. The trough will continue to hover around the
windward passage through the weekend and areas of divergence will
move through as fragments of a jet around the trough pass over the
local area.

At mid levels...High pressure over the windward islands will
continue to build north and spread over and beyond the local area.
On thursday a low pressure will form over the Bahama Islands
affecting the local area weakly, but it will move northwest.

At lower levels...High pressure over the Central Atlantic will
slowly weaken during the week and over the weekend...and moderate
east southeast trade winds will weaken and shift to the southeast
late in the week at the surface. Above the surface flow turns
more southerly on Sunday and better moisture is seen to start the
coming week.

&&

.DISCUSSION...Spotty light showers developed over the Caribbean
overnight and a few moved onshore across southern Puerto Rico. In
the pre-dawn hours heavier showers developed between Vieques and
Culebra and passed over the eastern tip of Puerto Rico and the
inner waters to the north. Little activity was seen yesterday
during the day and conditions are not expected to change much
today. It is expected that southeasterly flow will persist just
long enough today to allow the temperatures on the north coast of
Puerto Rico to touch the lower 90s. Dew points overnight in San
Juan were in the mid 70s despite the light land breeze and
although they will be lower during the day today, they will still
contribute to spotty areas of heat indices between 100 and 102
degrees in some places along the north coast and possibly along
the immediate south coastal areas as well.

According to the GFS, moisture gradually increases during the
week, over the weekend and again early next week, reaching over
2.2 inches of precipitable water mid week next week. The best
conditions for convection, that is showers and thunderstorms do
not occur until moisture from South America reach the area on
Saturday night and Sunday. This is when mid levels finally become
much wetter, but stability also increases somewhat. Therefore
expect increasing rain amounts and a higher risk of urban and
small stream flooding in Puerto Rico and possibly even in the U.S.
Virgin Islands.

&&

.AVIATION...Mostly VFR conds expected during the rest of the
forecast period. VCSH psbl across TJSJ/TIST/TISX this morning.
Isolated SHRA can be expected over NW PR...psbly affecting TJMZ
and TJBQ btwn 25/17- 23z. Sfc winds mainly from the east southeast
at 5 to 10 kts increasing at 10 to 20 with higher gusts.

&&

.MARINE...Winds and seas will fluctuate in the normal daily
pattern generally between 10 and 18 knots and between 4 to 6 feet
today and tomorrow, but conditions are expected to improve after
Wednesday. Small craft advisory conditions are not expected.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 78 88 77 / 20 30 10 20
STT 89 80 88 76 / 20 20 10 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
144 PM AST TUE MAY 24 2016

.SYNOPSIS...Strong surface high pressure across the central
Atlantic is expected to remain in place for the next few
days...causing easterly winds over the area...with a few
variations from ENE on Wednesday to ESE by Friday. Upper trough is
expected to remain across the western Atlantic and keep the local
islands under a ridge for the next few days. Available moisture
will remain near normal for the next few days...increasing
slightly for the latter part of the week.


&&

.DISCUSSION...Temperatures in the low 90s were observed today
across many of the coastal municipalities and other areas of lower
elevations. The higher elevations remained in the 80s. This was
due to the combination of the southeasterly wind and the Saharan
dust that is still over the local area. Very little to no shower
activity was observed over land areas in the morning hours and
only a few showers over the waters. High clouds moved in later in
the morning and into the afternoon hours. So far...no afternoon
showers have developed across land areas and satellite imagery
shows very little cloudiness developing due to convection. As the
Saharan dust diminishes overnight and the winds shift to a more
easterly direction overnight...isolated to locally scattered
showers are expected through tonight into Wednesday morning. Winds
are expected to shift to a more ENE direction on Wednesday while
moisture increases slightly. This means that we could observe some
showers develop across the interior into the SW quadrant of PR on
Wednesday afternoon while the rest of the local area remains with
only a slight chance of showers...mostly fair weather. This also
means that with the ENE winds we could observe slightly lower max
temperatures across the San Juan metro area.

Similar pattern is expected for Thursday but winds shifting to a
more easterly direction by Thursday afternoon. A few showers could
develop across western PR on Thursday afternoon while isolated to
scattered brief showers are expected elsewhere due to a slight
increase in moisture. This slight increase in moisture is expected
to linger through the weekend...which could increase the chances
of rain across the local area...especially on Saturday and Sunday
according to both the GFS and ECMWF models.

&&

.AVIATION...VFR conds expected thru the forecast period. However...
Saharan dust particles across the flying area will reduce somewhat
the visibilities at times...but VIS should remain above 6SM. SE
winds of 10-20 kt will prevail below FL050.


&&

.MARINE...Small craft should exercise caution as seas will be up
to 6 feet and winds up to 20 knots the rest of today and tonight.
Seas will diminish slightly on Wednesday and for the following few
days.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 88 77 87 / 30 10 20 30
STT 80 88 76 87 / 20 10 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
547 AM AST WED MAY 25 2016

.SYNOPSIS...
A mid to upper level ridge will hold across the Northeastern
Caribbean, as a trough meander over the Western Caribbean. Ridge
aloft is expected to slowly erode during the Memorial Day
weekend. At lower levels, a strong high pressure across the
central Atlantic and an induced trough northwest of the local
islands will continue to promote an easterly winds through friday.

&&

.DISCUSSION...
The doppler radar detected an increase in shower activity across
the local waters...some of these showers moved across the
windward sections overnight. These showers were brief, but the
Doppler Radar estimated rainfall accumulations around half an inch
across some locations of East and Southeast P.R., as well as
traces across the U.S. Virgin Islands. The winds were mainly from
the east at less than 10 mph and the temperatures ranged from
around 80s along the coastal areas to the mid 60s across the
mountainous areas.

Satellite imagery indicate a dry air mass approaching the
islands...this will combined with a ridge aloft to limit shower
activity across the local islands during the morning hours.
Meanwhile, the ridge aloft will favor a generally fair weather
pattern, but under the prevailing northeasterly wind flow...a few
showers and possibly a thunderstorm or two are possible across the
interior and southwestern sections of Puerto Rico this afternoon.
Elsewhere, expect little to no shower activity.

Both the GFS and the ECMWF guidances are suggesting the erosion of
the upper level ridge by the upcoming weekend. As a result, the
potential for shower and thunderstorm activity should increase
across the local region. Also...the guidances indicate the
development of a Surface Low near the Bahamas...if this pattern
hold...it will enhance the transport of ITCZ moisture across the
Caribbean region...and possibly across the local area by the
upcoming weekend and into the early part of the upcoming week.

&&

.AVIATION...VFR conds expected thru the rest of the forecast period.
Areas of high clouds will continue to move across the flying area
thru 26/06Z. Light passing SHRA over local waters movg just south of
west. Sfc winds E-ESE 5 to 15 kt incrg til 25/18z with gusts near
coast of nrn PR to 25 kt. Winds switch to north btwn FL070-120 then
become W by FL170 and increase to 70 kt by FL430.

&&

.MARINE...Mariners can expect seas between 3 and 5 feet across
most of the local waters and winds below 18 knots. However, winds
up to 20 knots are possible across the coastal waters of northern
and southern PR. Therefore small craft operators should exercise
caution across these areas. Tranquil marine conditions are
expected to prevailed during the rest of the work week. For the
beach goers, there is a moderate risk of rip currents for most of
the local beaches, refer to the surf zone forecast for more
details.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
158 PM AST WED MAY 25 2016

.SYNOPSIS...Mid to upper level ridge will continue to dominate
the local weather conditions through the end of the work week. At
low levels...surface high pressure over the Central Atlantic will
weakens...diminishing the trade winds across the local region. Then...
a deep layer trough will amplify over Cuba and Bahamas during the
next few days...favoring the moisture transport across the Central
and East Caribbean during the weekend. As a result...weather pattern
will become moist and unstable across the local area by the end
of the week.

&&

.DISCUSSION...Sunny skies have prevailed across most of Puerto
Rico today...resulting in strong daytime heating across the local
islands. Although...max temp remains in the upper 80s across most
of the islands...the heat index reached the mid to upper 90s. Sea
breeze formed over western PR early this afternoon. This have
resulted in shower development over the west and southwest Puerto
Rico so far this afternoon. The activity is forecast to taper off
before sunset.

Ridge aloft combined with somewhat dry air at mid level will
likely result in a generally fair weather pattern across the
islands through Friday. Typical showers over western PR will
develop each afternoon due to the sea breeze convergence and the
orographic effects. Mid to upper clouds will stream across the
islands from late Thursday into the weekend.

Operational models suggest a wetter pattern by the end of next
week as a mid-upper level trough amplifies over Cuba/Bahamas. This
will bring deep tropical moisture into the local area. As a result...
High moisture content combined with somewhat favorable upper dynamics
will increase the potential for organized convection across the
forecast area...especially Sunday and Monday.

&&

.AVIATION...VFR conds expected thru the forecast period. Afternoon
showers across SW-PR may affect the vicinity of TJMZ until 25/22z
but the rest of the terminals should remain with fair weather...
only light and brief SHRA in the vicinity during the night. Winds
from the East at around 10kt with sea breeze variations until
25/23Z...then winds decreasing overnight...becoming light and
variable...increasing once again and from the East after 26/12Z.

&&

.MARINE...Winds and seas will subside sightly as surface high
pressure over the Central Atlantic weakens. Therefore...expect
moderate winds and seas of 3-5 ft over the next 5-7 days. No Small
Craft Advisories are anticipated during the forecast period.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 88 77 90 / 20 20 40 40
STT 78 87 77 87 / 20 20 40 40

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
555 AM AST THU MAY 26 2016

.SYNOPSIS...
At upper levels, a mid to upper level ridge will continue over the
Eastern Caribbean. While a trough, and it associated Low near
Bahamas, continues anchored over the Western Caribbean. At low
levels, a surface high pressure over the Central Atlantic will
weakens. An induced surface low, off to the north of Hispanola,
will move toward the Florida Peninsula.

&&

.DISCUSSION...
Mostly cloudy skies prevailed over during the overnight hours...as
mid to upper level clouds moved over the region. The Doppler
radar detected showers moving across the local waters and some of
them moved inland but no significant amounts were measured.
Satellite imagery showed plenty of clouds across the region or
moving toward the local islands, as a result partly to mostly
cloudy skies are expected this morning. Although little to no
shower activity is expected...some brief passing showers still
possible across the eastern sections of Puerto Rico and the U.S.
Virgin Islands this morning. Then during the afternoon, locally
and diurnally induced convection is likely mainly across portions
of the west interior sections of Puerto Rico. Elsewhere, expect
little to no shower activity. A similar pattern is expected on
Friday.

Both the GFS and the ECMWF guidances are suggesting the erosion of
the upper level ridge...as a deep layer trough amplifies over Cuba
and Bahamas during the next few days. This pattern will promote
the transport of tropical moisture across the Caribbean region. If
this pattern hold, the potential for shower and thunderstorm
activity should increase across the local region during the
weekend and the upcoming week.

&&

.AVIATION...VFR conds expected to prevail at all TAF sites during
the forecast period, with thin but incrg high/mid clouds moving
across the from the SW. SHRA/TSRA development expected across W PR
aft 26/17z and will cause mtn obscurations and areas of MVFR conds
in and around TJMZ through 26/22z. Winds increasing to 10 to 15
knots from the east after 26/12Z. Winds alf bcmg SW arnd FL170 and
incrg to W 60 kt by FL460.

&&

.MARINE...Winds and seas will continue to slowly subside across
the region as the surface High pressure over the Central Atlantic
weakens. Therefore...expect moderate winds and seas of 3-5 ft over
the region. However...if the model guidance are correct...mariners
should expect an increase in shower and thunderstorm activity
across the local waters by the weekend and into the upcoming week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 79 90 76 / 20 40 40 30
STT 89 79 87 78 / 20 40 40 40