Caribbean - Central America Weather

[cycloneye]

The forecast mentions some moisture for the Leeward Islands on Sunday Night.Does that mean Rain as well?
If so,how much Rain is expected to fall in the Northern Leeward Islands?
And how long will it last for the Northern Leeward Islands?
Thanks in Advance.

Maybe not a big rain event but periods of rain sometimes heavy may fall from Sunday thru Tuesday.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
552 AM AST SUN MAY 8 2016

.SYNOPSIS...FRONTAL BOUNDARY ACROSS THE MONA PASSAGE WILL MOVE
SLOWLY EAST TODAY. SHOWERS AND THUNDERSTORMS EXPECTED OVER MOST OF
THE AREA TODAY.

&&

.DISCUSSION...VERY ACTIVE NIGHT ACROSS THE FORECAST AREA. NUMEROUS
SHOWERS WITH SCATTERED THUNDERSTORMS AFFECTED THE WESTERN HALF OF
PUERTO RICO OVERNIGHT. SEVERAL FLOOD ADVISORIES...SPECIAL MARINE
WARNINGS AND SPECIAL WEATHER STATEMENT WERE ISSUED. BROAD POLAR
TROUGH OVER THE WESTERN ATLANTIC IS PRESSING AGAINST THE STRONG
HIGH PRESSURE OVER THE CENTRAL ATLANTIC. THE TROUGH IS SUSTAINING
A FRONTAL BOUNDARY LOCATED OVER THE MONA PASSAGE. TROUGH/SHEARLINE
WILL CONTINUE TO SUPPORT NUMEROUS THUNDERSTORMS ACROSS THE MONA
PASSAGE AND THE ATLANTIC WATERS NORTH OF PR. SOME OF THESE
SHOWERS/THUNDERSTORMS WILL CONTINUE TO AFFECT THE LOCAL AREA
THROUGH THIS AFTERNOON.

TONIGHT...SHOWER ACTIVITY WILL DIMINISH SOMEWHAT AS FRONTAL
BOUNDARY/SHEAR LINE MOVES OUT OF THE AREA. HOWEVER...TRADE WINDS
WILL BRING MOISTURE FROM THE EAST ASSOCIATED WITH THE REMNANT OF
THIS BOUNDARY...AND WILL AFFECT THE LOCAL AREA MONDAY INTO
TUESDAY. THEREFORE...A WET PATTERN IS EXPECTED THROUGH AT LEAST
MID WEEK.

&&

.AVIATION...MVFR AND IFR COND EXPECTED OVER TJBQ/TJMZ/TJPS/TSJU
DUE TO FRONTAL BOUNDARY MOVING OVER THE AREA. SHRA AND TS WITH
LIGHTNING EXPECTED TO CONTINUE ACROSS THE MONA PASSAGE AND
ATLANTIC WATERS IMPACTING MAINLY THE FLYING AREA OF TJBQ/TJMZ/TJSJ
DURING THE MORNING HOURS. VARIABLE LOW LEVEL WINDS WITH POS WIND
GUSTS UP TO 40 KTS IN/NEAR SHRA AND TS.

&&

.MARINE...SHOWERS AND STRONG THUNDERSTORMS WILL CONTINUE TO
MAINTAIN HAZARDOUS MARINE CONDITIONS THROUGH LATE THIS AFTERNOON.
MAIN HAZARDS WILL BE EXCESSIVE LIGHTNING AND STRONG GUSTY WINDS UP
TO 40 KTS. SEAS UP TO 6 FEET AND WINDS UP TO 20 KNOTS ARE
EXPECTED...MAINLY OVER THE ATLANTIC WATERS. SMALL CRAFT SHOULD
EXERCISE CAUTION ACROSS THESE WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 87 76 / 50 50 50 40
STT 86 77 85 75 / 50 60 60 50

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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
353 PM AST SUN MAY 8 2016

.SYNOPSIS...AT UPPER LEVELS...ALTHOUGH THE UPPER TROUGH WEST OF
THE AREA WEAKENS THROUGH FRIDAY...A CUT-OFF LOW FORMS NORTH OF THE
WINDWARD PASSAGE BRIEFLY ON TUESDAY AND THE TROUGH HOLDS WEST OF
THE AREA UNTIL IT DISSIPATES. HIGH PRESSURE THEN DOMINATES THE
SOUTHERN CARIBBEAN THROUGH MID WEEK NEXT WEEK.

AT MID LEVELS...TROUGHINESS DOMINATES THE CENTRAL CARIBBEAN AND
HISPANIOLA THROUGH THURSDAY. HIGH PRESSURE THEN NOSES INTO THE
CARIBBEAN FROM THE EAST...BUT THE CENTER OF THE HIGH HOLDS BACK
OVER THE WESTERN TROPICAL ATLANTIC. MOISTURE AT MID LEVELS IS
MODERATE...EXCEPT FOR GOOD MOISTURE ON THURSDAY AND THE FOLLOWING
WEEKEND.

AT LOWER LEVELS...AS THE TROUGH WEAKENS OVER THE LOCAL AREA...HIGH
PRESSURE IN THE CENTRAL ATLANTIC ALSO WEAKENS AND STRETCHES ACROSS
THE SUB TROPICAL ATLANTIC TO THE EAST COAST OF THE UNITED STATES.
WHEN HIGH PRESSURE RETURNS TO THE EASTERN ATLANTIC AFTER MID
WEEK...FLOW AGAIN BECOMES MORE SOUTHEASTERLY.

&&

.DISCUSSION...THE FRONTAL BOUNDARY THAT MOVED INTO THE LOCAL AREA
WITH VIGOR FADED DURING THE DAY AND BY 08/18Z ONLY A FEW AREAS OF
LIGHT TO MODERATE RAIN WERE LEFT IN THE LOCAL CARIBBEAN WATERS. A
FEW SMALL SHOWERS ALSO DEVELOPED AFTER NOON IN LUQUILLO. THEY ARE
DRIFTING WITH THE LOW LEVEL FLOW TO THE NORTH NORTHWEST.

THE GFS HAS BACKED AWAY FROM THE HIGHER PROBABILITIES OF RAIN THAT
IT HAD FOR THE LOCAL AREA TONIGHT AND MONDAY. IT IS ALSO NO LONGER
SHOWING ANY DIVERGENCE ALOFT OVER PUERTO RICO OR THE U.S. VIRGIN
ISLANDS UNTIL MONDAY WHEN POSITIVE VALUES ARE SLIGHT. WITH THE
TROUGH TO THE WEST AT UPPER LEVELS AND A WEAK DOWNSTREAM-SIDE JET
ON THE RIGHT HAND SIDE OF THE TROUGH PULLING BACK OVER PUERTO RICO
ON TUESDAY AND PRECIPITABLE WATER HOLDING ABOVE 1.9 INCHES...
CONDITIONS ARE STILL FAVORABLE FOR SHOWERS AND ISOLATED
THUNDERSTORMS. DYNAMICS FOR THE FRONT HAVE GREATLY DISSIPATED
DURING THE DAY...BUT SHOULD RE-GENERATE A LITTLE OVERNIGHT.
FORWARD MOVEMENT IS NOT EXPECTED...HOWEVER...AND THE UPPER LEVEL
TROUGH DOES NOT INCREASE IN STRENGTH DURING THE NEXT FEW DAYS.
ALSO CLOUD COVER WILL PREVENT INTENSE HEATING OVER LAND. THEREFORE
SHOWER ACTIVITY WILL BE MODEST AND URBAN AND SMALL STREAM
FLOODING...IF ANY...WILL BE VERY LOCALIZED. SHOWER ACTIVITY WILL
DIMINISH TUESDAY NIGHT AND WEDNESDAY...BUT GOOD MOISTURE AND
DYNAMICS ARE TO INCREASE OVER THE WEEKEND. SOME INCREASED ACTIVITY
IS EXPECTED OVER THE WEEKEND...BUT THE GFS SHOULD NOT BE TRUSTED
TO DELIVER THE STRONG SIGNATURE AND DYNAMICS IT IS NOW SUGGESTING.

&&

.AVIATION...MID TO LEVEL HIGH CLOUDS LIMITED THE SHRA/TSRA
DEVELOPMENT OVER LAND AREAS EARLY THIS AFTERNOON. VFR CONDS ARE
EXPECTED ACROSS MUCH OF THE TERMINALS. HOWEVER...SHRA/TSRA CAN STILL
DEVELOP OVER THE WATERS AND AFFECT THE TERMINALS FROM EASTERN PR TO
THE LEEWARD ISLANDS DURING THE OVERNIGHT HOURS. LIGHT AND VARIABLE
WINDS WILL CONTINUE AT THE SFC...WITH A SOUTHEASTERLY WIND COMPONENT
ALOFT.

&&

.MARINE...SEAS WILL INCREASE SOME ON TUESDAY BUT ARE NOT EXPECTED
TO REACH SMALL CRAFT ADVISORY CONDITIONS DURING THE NEXT 7 DAYS.
WIND WAVES FROM THE EAST WILL PREVAIL.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 87 76 86 / 50 50 40 40
STT 76 85 75 85 / 60 50 50 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
540 AM AST MON MAY 9 2016

.SYNOPSIS...AT UPPER LEVELS...A TROUGH WILL SHARPEN OVER THE
WINDWARD PASSAGE AND BRIEFLY FORM A CUT-OFF LOW KEEPING THE LOCAL
AREA UNDER THE EXIT JET OF THE LOW TOMORROW. THE TROUGH WILL MOVE
OVER HISPANIOLA MID WEEK AND ACROSS PUERTO RICO THURSDAY NIGHT IN
A MUCH WEAKENED FORM. A SHORT WAVE TROUGH WILL CROSS THROUGH THE
AREA VERY RAPIDLY ON SUNDAY WITH MORE UNSETTLED WEATHER.

AT MID LEVELS...A WEAK TROUGH WILL HOVER JUST WEST OF THE AREA IN
THE GENERALLY HIGH PRESSURE OF THE TROPICAL ATLANTIC AND THE
CARIBBEAN. MID LEVELS ARE MODESTLY MOIST...BUT PATCHES OF VERY
MOIST AIR TRAVEL THROUGH AS PLUMES OF MOISTURE MOVE THROUGH THE
AREA.

AT LOWER LEVELS...HIGH PRESSURE DOMINATES THE SUB TROPICAL
ATLANTIC...BUT FLOW BECOMES MORE SOUTHEASTERLY LATE THIS WEEK AS
HIGH PRESSURE BUILDS AGAIN OVER THE EAST CENTRAL ATLANTIC. PATCHES
OF DRIER AIR PASS THROUGH WEDNESDAY...THURSDAY AND FRIDAY...BUT
MOISTURE RETURNS OVER THE WEEKEND. A BOUNDARY OVER THE U.S. VIRGIN
ISLANDS WILL MOVE BACK OVER PUERTO RICO TODAY BRINGING AN INCREASE
IN SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...SHOWERS DEVELOPED OVERNIGHT OVER THE CARIBBEAN AND
ATLANTIC WATERS AROUND SAINT THOMAS...SAINT JOHN...CULEBRA AND
VIEQUES. SOME LEFT UP TO 2 INCHES OVER THE LOCAL WATERS. CULEBRA
DID RECEIVE A SIGNIFICANT SHOWER OVERNIGHT. BY 5 AM AST A FEW TOPS
WERE SEEN AS HIGH AS 40 KFT. ALL INDICATIONS ARE THAT THE BOUNDARY
TO CROSS THE AREA WILL INCREASE IN STRENGTH AND THAT MORE SHOWERS
AND THUNDERSTORMS THAN SEEN YESTERDAY AFTERNOON WILL DEVELOP OVER
THE LOCAL WATERS AND INTERIOR PUERTO RICO TODAY. THE UPPER LEVEL TROUGH
TO THE WEST WILL HOLD SOUTHWEST FLOW OF UP TO 60 KNOTS OVER THE
AREA TODAY WITH SOME AREAS OF DIVERGENCE MOVING OVER THE ISLAND
THIS AFTERNOON. THE BEST DIVERGENCE ALOFT IS NORTHEAST OF PUERTO
RICO IN THE NORTHEAST CORNER OF THE FORECAST AREA AND WELL BEYOND
HOWEVER. SURFACE WINDS TODAY WILL SHIFT FROM ALMOST NORTHEAST TO
EAST SOUTHEAST...BUT CLOUD COVER SHOULD PRECLUDE MAXIMUM
TEMPERATURES AS HIGH AS MOS WAS GIVING PUERTO RICO. BROUGHT SAN
JUAN DOWN FROM 88 TO 85 AS ONLY 82 OCCURRED YESTERDAY AND CLOUDY
SKIES ARE EXPECTED AGAIN TODAY. SINCE 1000-850 MB THICKNESS VALUES
DROP 8 METERS BETWEEN 09/00Z AND 10/06Z IT IS NOT CLEAR WHY MOS
WANTS TO BRING TEMPERATURES UP 6 DEGREES TODAY. MOISTURE DROPS
DURING THE DAY ON TUESDAY...BUT INCREASES AGAIN ON
WEDNESDAY...WITH ANOTHER MINIMUM ON THURSDAY NIGHT. MOISTURE
INCREASES AGAIN OVER THE WEEKEND AND PRESENT INDICATION BRING
SUPPORTING DYNAMICS OVER THE AREA FOR MORE SHOWERS AND
THUNDERSTORMS. THE GFS SHOWS GOOD DYNAMICS THIS TUESDAY THROUGH
THURSDAY IN ALTERNATING CYCLES. SO THIS SHOULD PROVE TO BE A
MOSTLY CLOUDY WEEK WITH SHOWERS AND A FEW THUNDERSTORMS. PRESENTLY
EXPECT SOME URBAN AND SMALL STREAM FLOODING TODAY AND POSSIBLY
TUESDAY AND THURSDAY AND OVER THE WEEKEND AND INTO THE FOLLOWING
MONDAY.

&&

.AVIATION...MOSTLY VFR CONDS ARE EXPECTED ACROSS THE TERMINALS TIL
AROUND 09/15Z. HOWEVER...SHRA/TSRA WILL CONTINUE TO DEVELOP OVER
THE WATERS AND AFFECT THE TERMINALS FROM EASTERN PR TO THE LEEWARD
ISLANDS THRU 09/15Z. THEN...AREAS OF MVFR IN CIGS AND VSBYS WITH
WIDESPREAD MTN OBSCURATIONS ARE EXPECTED THROUGH 10/00Z. LIGHT
AND VARIABLE WINDS WILL BECOME ENE 5 TO 15 KT...SWITCHING TO ESE
AFT 09/18Z.

&&

.MARINE...WINDS AND SEAS INCREASE TODAY AND TUESDAY. CURRENT
EXPECTATION IS THAT SEAS WILL REMAIN BELOW 7 FEET INSIDE THE
FORECAST AREA...BUT BUOY 41043 WILL LIKELY SEE 7 FEET BY TUESDAY.
SEAS DIMINISH AFTER TUESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 75 86 76 / 60 50 50 10
STT 86 77 87 77 / 60 60 60 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
137 PM AST MON MAY 9 2016

.SYNOPSIS...AT UPPER LEVELS...A TROUGH OVER HAITI WILL ACCELERATE
SOUTHWEST FLOW OVER THE AREA TUESDAY AND WEDNESDAY. THE TROUGH
WILL WEAKEN AS IT PASSES THROUGH ON FRIDAY...BUT THE JET WILL
PERSIST UNTIL FRIDAY AFTERNOON. ANOTHER WEAK SHORT WAVE WILL PASS
THROUGH ON SUNDAY WITH SOME UPPER LEVEL DIVERGENCE ABLE TO ENHANCE
SHOWERS AND THUNDERSTORMS.

AT MID LEVELS...WEAK TROUGHING CONTINUES OVER THE CENTRAL
CARIBBEAN THROUGH THE WEEK. ANOTHER SHORT WAVE DIGS BRIEFLY INTO
THE WESTERN CARIBBEAN OVER THE WEEKEND...LIFTING OUT THROUGH THE
LOCAL AREA ON SUNDAY. MID LEVEL MOISTURE DIMINISHES TONIGHT
THROUGH TUESDAY NIGHT. THEN A PLUME OF MOISTURE BRUSHES BY TO OUR
SOUTH THURSDAY AND FRIDAY FOLLOWED BY A SECOND WAVE OF MOISTURE
THAT ARRIVES SATURDAY NIGHT TO CONTINUE THROUGH SUNDAY.

AT LOWER LEVELS...AS THE RIDGE TO OUR NORTH BUILDS WEST THE WEAK
TROUGH OVER THE AREA MOVES ACROSS HISPANIOLA TONIGHT AND TUESDAY.
HIGH PRESSURE THEN TRANSITS THE ATLANTIC FROM NEW YORK AND BY NEXT
WEEK STRONGER HIGH PRESSURE WILL BUILD IN THE EAST CENTRAL
ATLANTIC OCEAN. THIS WILL MAINTAIN AND STRENGTHEN TRADE WIND FLOW
TONIGHT AND TUESDAY THAT WILL MODERATE AND TURN MORE
SOUTHEASTERLY OVER THE WEEKEND.

&&

.DISCUSSION...SHOWERS BEGAN BUILDING OVER INTERIOR PUERTO RICO A
LITTLE BEFORE NOON. SOON AFTER...THUNDERSTORMS HAD DEVELOPED WITH
SOME TOPS AS HIGH AS 47 KFT. HEAVY RAIN CONTINUED OVER A NUMBER OF
AREAS FROM AGUADA TO PONCE AND OVER TO CABO ROJO THAT REQUIRED THE
ISSUANCE OF URBAN AND SMALL STREAM FLOOD ADVISORIES. PATCHES OF
DIVERGENCE ALOFT HAVE AIDED THE DEVELOPMENT OF THESE STORMS OVER
PUERTO RICO. THESE AREAS OF DIVERGENCE DISSIPATE OVER NIGHT AND
RETURN ON TUESDAY WITH LESS INTENSITY. MOISTURE ALSO REACHES A
MINIMUM FOR THE WEEK ON TUESDAY AFTER MORNING SHOWERS DAMPEN
EASTERN PUERTO RICO. EXPECT LESS URBAN AND SMALL STREAM FLOODING
TUESDAY THAN TODAY. AFTER MID WEEK...PATCHES OF MOISTURE JOIN A
PLUME OF MOISTURE OUT OF SOUTH AMERICA TO GRADUALLY BOOST THE
PRECIPITABLE WATER VALUES BEYOND TWO INCHES BY SUNDAY. THIS SHOULD
MEAN ACTIVE WEATHER IN WESTERN PUERTO RICO EACH AFTERNOON WITH AN
INCREASE IN URBAN AND SMALL STREAM FLOODING OVER THE WEEKEND.

&&

.AVIATION...OBSCD MTNS AND SHRA/TSRA WILL CONTINUE ACROSS THE
WESTERN HALF OF PR THRU AT LEAST 22Z...THIS WILL IMPACT MAINLY
JMZ/JBQ AND THE VCNTY OF JPS. VFR ELSEWHERE WITH BRIEF PERIODS OF
VCSH AT TIMES. LOW LEVEL WINDS WILL CONTINUE FROM THE EAST BETWEEN
10-20 KTS...BUT LIGHT AND VARIABLE AT THE SFC OVERNIGHT.


&&

.MARINE...AFTER FLIRTING WITH 7 FEET SEAS ON TUESDAY...ESPECIALLY
NORTH OF THE LOCAL AREA...SEAS WILL DIMINISH THROUGH FRIDAY. SMALL
CRAFT ADVISORIES MAY BE NEEDED ON TUESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 87 76 87 / 40 40 10 20
STT 77 88 77 86 / 30 30 20 20

&&

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
502 AM AST TUE MAY 10 2016

.SYNOPSIS...UPPER TROUGH WITH AXIS JUST WEST OF THE FORECAST AREA
WILL CONTINUE TO FILL AND LIFT NORTHWARDS THROUGH WEDNESDAY WITH
THE UPPER LEVEL WINDS BECOMING MORE ZONAL/WESTERLY BY THURSDAY.
BY FRIDAY AND SATURDAY A SHORT WAVE TROUGH IS FORECAST TO MOVE
ACROSS THE WESTERN ATLANTIC AND PASS JUST NORTH OF THE REGION ON
SUNDAY. IN THE LOW LEVELS...HIGH PRESSURE ACROSS THE WEST AND EASTERN
ATLANTIC WILL REMAIN IN PLACE OVER THE NEXT COUPLE OF DAYS. THE
RIDGE IS TO THEN REESTABLISH NORTH OF THE REGION BY WEDNESDAY AND
THURSDAY...AS THE FRONTAL TROUGH ACROSS HISPANIOLA AND THE MONA
PASSAGE CONTINUED TO SLOWLY WEAKEN...AND THE EASTERLY TRADE WINDS
INCREASE IN RESPONSE TO THE TIGHTENING OF THE LOCAL PRESSURE GRADIENT.

&&

.DISCUSSION...UPPER TROUGH WEST OF THE AREA ALTHOUGH SLOWLY LIFTING
NORTHWARD AND WEAKENING WILL HELP MAINTAIN UNSTABLE CONDITIONS
ALOFT AT LEAST THROUGH TODAY. DURING THE OVERNIGHT AND EARLY
MORNING HOURS... SHOWERS CONTINUE TO DEVELOP AND MOVE WESTWARD
ACROSS THE COASTAL WATERS. SOME SHOWERS MOVE INLAND ACROSS PARTS
OF THE NORTH AND EAST COASTAL SECTIONS OF THE ISLANDS PRODUCING
PERIODS OF MODERATE TO LOCALLY HEAVY RAINFALL.

THE PREVIOUS TJSJ TUE 10/00Z UPPER AIR SOUNDING AS WELL AS THE
SATELLITE DERIVED PRECIPITABLE WATER ANALYSIS SUGGEST LAYERED
PWAT VALUES WERE JUST BELOW TWO INCHES ACROSS THE REGION. THE
RECENT MODEL GUIDANCE AS WELL AS THE SATELLITE IMAGERY BOTH
SUGGEST LESSER MOISTURE ADVECTION ACROSS THE REGION TODAY THROUGH
WEDNESDAY AS THE SURFACE TROUGH AND ASSOCIATED TRAILING MOISTURE
WILL EXIT THE FORECAST AREA. NEVERTHELESS... THERE WILL BE SUFFICIENT
LOW LEVEL MOISTURE AND INSTABILITY ALOFT TO COMBINE WITH DIURNAL
EFFECTS TO SUPPORT CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE INTERIOR
AND WEST SECTIONS OF PUERTO RICO. LESSER SHOWER ACTIVITY IS EXPECTED
OVER THE VIRGIN ISLANDS DURING THE AFTERNOON.

ON WEDNESDAY AND THURSDAY LESSER MOISTURE ADVECTION EXPECTED BUT
LOCAL AND DIURNAL EFFECTS WILL LEAD TO SOME AFTERNOON CONVECTION
IN MOSTLY ISOLATED AREAS...BUT ESPECIALLY OVER THE WEST INTERIOR
AND NORTHWEST SECTIONS OF PUERTO RICO.

BY FRIDAY AND INTO THE WEEKEND...MODEL GUIDANCE SUGGEST THAT
ATLANTIC HIGH IS TO RELOCATE AND SPREAD ACROSS THE CENTRAL AND
EAST ATLANTIC AS A COLD FRONT AND ASSOCIATED MOISTURE IS FORECAST
TO EXIT THE EASTERN SEABOARD AND MOVE ACROSS THE WEST ATLANTIC. BY
THEN THE LOCAL WINDS ARE TO BECOME MORE SOUTHEASTERLY AND LOW
LEVEL MOISTURE CONVERGENCE INCREASES AND POOLS ACROSS THE REGION
AS AN INDUCED SURFACE TROUGH SETS UP ACROSS THE AREA. THIS IN TURN
WILL INCREASE THE CHANCE FOR SHOWERS AND THUNDERSTORMS ONCE AGAIN
BY FRIDAY AND INTO THE WEEKEND. FOR NOW WILL CONTINUE TO MONITOR
OVER THE NEXT FEW DAYS AND MAKE NECESSARY ADJUSTMENT TO THE LONG
TERM FORECAST PACKAGE.

&&

.AVIATION...PASSING SHRA WILL CONTINUE ACROSS THE SURROUNDING WATERS
OF PR/USVI THROUGH LATE THIS MORNING...CAUSING MAINLY VCSH AND -RA
PERIODS AT IST/ISX AND THE EASTERN PR TERMINALS. SHRA/TSRA AND MTNS
OBSCD EXPECTED ACROSS THE WESTERN HALF OF PR BTWN 16Z-23Z. IMPACTING
MAINLY JMZ WITH AT LEAST MVFR CONDS...VCTS AT JPS/JBQ AND VCSH AT
JSJ. SFC WINDS FROM THE EAST AT 10-15 KTS WITH HIGHER GUSTS...SEA
BREEZE VARIATIONS AFT 13Z.


&&

.MARINE...TRADE WINDS WILL INCREASE ACROSS THE REGIONAL WATERS TODAY
THROUGH AT LEAST EARLY WEDNESDAY...WITH SEAS BUILDING TO 4-6 FT ACROSS
MOST OF THE LOCAL WATERS. SEAS WILL RETURN TO 3-5 FEET DURING THE LATTER
PART OF THE WEEK. SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS MOST OF
THE LOCAL WATERS DUE TO THE CHOPPY CONDITIONS. PLEASE REFER TO THE
LATEST COASTAL WATERS FORECAST ISSUED BY WFO SAN JUAN PR.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 87 75 / 40 10 20 10
STT 88 77 86 76 / 50 40 40 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
208 PM AST TUE MAY 10 2016

.SYNOPSIS...AT UPPER LEVELS...AN UPPER TROUGH IS WEAKENING OVER
HISPANIOLA AND THE WINDWARD PASSAGE AND WILL SLOWLY ADVANCE
EASTWARD TOWARD THE AREA CARRYING A JET AHEAD OF IT. THIS TROUGH
WILL MOVE INTO THE LEEWARD ISLANDS ON FRIDAY.

AT MID LEVELS...VERY WEAK TROUGHINESS OVER THE LOCAL AREA WILL
RE-FOCUS OVER THE WESTERN CARIBBEAN ON SATURDAY. HIGH PRESSURE
WILL DOMINATE THE AREA. A PLUME OF MID LEVELS MOISTURE WILL RETURN
TO THE LOCAL CARIBBEAN WATERS FROM SOUTH AMERICA...BUT THE
HEAVIEST MOISTURE WILL CURVE EAST OVER THE LOCAL WATERS BEFORE
REACHING PUERTO RICO OR THE U.S. VIRGIN ISLANDS. A SECOND PLUME
WILL REACH THE AREA ON SATURDAY AND SUNDAY TO ENRICH MID LEVEL
MOISTURE.

AT LOWER LEVELS...THE SURFACE HIGH PRESSURE THAT EXTENDS FROM THE
CENTRAL ATLANTIC TO NORTHERN FLORIDA WILL WEAKEN SOMEWHAT AND
EXTEND FURTHER EAST DURING THE WEEK. THIS WILL MAINTAIN MODERATE
EASTERLY TRADE WINDS THROUGH THURSDAY. WINDS WILL SHIFT TO THE
EAST SOUTHEAST ON FRIDAY. EAST NORTHEAST FLOW WILL BRING DRIER AIR
OVER THE AREA WEDNESDAY THROUGH THURSDAY. BETTER MOISTURE WILL
MOVE INTO THE AREA ON FRIDAY AND CONTINUE THROUGH THE WEEKEND.

&&

.DISCUSSION...WINDS WERE STRONGER JUST ABOVE THE SURFACE TODAY SO
THE INITIAL CONVECTION THAT FORMED MOVED OFF AGAIN AND MIXING
ARRESTED THE EARLY DEVELOPMENT. NEW CELLS HAVE SINCE DEVELOPED AND
ONE IS OVER 30 KFT AT THIS TIME. CONVECTION IS NOT EXPECTED TO
DEVELOP AS EXTENSIVELY TODAY...HOWEVER MUCH BETTER DYNAMICS ARE NOW
BEING FORECAST FOR TOMORROW AS THE JET AROUND THE UPPER LEVEL
TROUGH MOVES TO JUST WEST OF THE AREA AND DIVERGENCE INCREASES
MARKEDLY. AFTER THIS...LOW LEVEL MOISTURE WILL
DECREASE CONSIDERABLY AND CONVECTION WILL BE MORE ISOLATED.
BETTER MOISTURE AT ALL LEVELS IS EXPECTED OVER THE WEEKEND. URBAN
AND SMALL STREAM FLOODING WILL BE POSSIBLE THEN AND SHOWERS WILL
COVER MUCH MORE OF THE LOCAL ISLANDS.

&&

.AVIATION...SHRA/-TSRA AND MTNS OBSCD EXPECTED ACROSS WESTERN PR
THRU 22Z. VCSH ELSEWHERE WITH BRIEF -RA ACROSS THE USVI TERMINALS.
TRADE WIND SHOWERS INCREASING LATER THIS EVENING ACROSS THE LEEWARD
TERMINALS...REACHING THE USVI/EASTERN PR TERMINALS BY DAYBREAK ON
WEDNESDAY. LOW LEVEL WINDS WILL CONTINUE FROM THE EAST AT 10-20
KTS.

&&

.MARINE...SEAS WILL DIMINISH TONIGHT AND ARE NOT EXPECTED AT THESE
LEVELS FOR AT LEAST ANOTHER 5 DAYS. SMALL CRAFT ADVISORY
CONDITIONS ARE NOT EXPECTED.

&&

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
550 AM AST WED MAY 11 2016

.SYNOPSIS...UPPER LEVEL TROUGH OVER HISPANIOLA CONTINUES TO WEAKEN
AND IS EXPECTED TO FLATTEN OUT BY THURSDAY...WITH CONTINUED ZONAL
FLOW THROUGH THE WEEKEND. SURFACE HIGH PRESSURE OVER THE CENTRAL
ATLANTIC IS MOVING SLOWLY EASTWARD AND IS EXPECTED TO CONTINUE
DOING SO THROUGH THE WEEKEND. THIS WILL KEEP AN E-SE WIND FLOW
THROUGH THE LOCAL ISLANDS FOR THE NEXT SEVERAL DAYS. ABUNDANT
AVAILABLE MOISTURE IS ALSO EXPECTED TO REMAIN OVER THE AREA FOR
THE NEXT SEVERAL DAYS. BRIEF MORNING SHOWERS MOVING IN FROM THE
EAST AND AFTERNOON SHOWERS AND THUNDERSTORMS ARE EXPECTED.

&&

.DISCUSSION...AVAILABLE MOISTURE AND AN EAST SOUTHEAST WIND HAS
KEPT THE LOCAL AREA WITH SCATTERED BRIEF SHOWERS ACROSS THE LOCAL
WATERS...USVI...AND EASTERN PR...ALTHOUGH THE ACCUMULATIONS HAVE
GENERALLY BEEN MINIMAL. THE CURRENT PATTERN IS SUCH THAT THESE
SCATTERED BRIEF SHOWERS ARE EXPECTED THROUGH THE DAY WITH MAYBE A
SLIGHT DECREASE IN THE AFTERNOON WHEN IT COMES TO OVERALL
COVERAGE. HOWEVER THE AFTERNOON CONVECTION MAY CAUSE SHOWERS AND
THUNDERSTORMS...PARTICULARLY ACROSS WESTERN PR AS THE AVAILABLE
MOISTURE COMBINES WITH THE DIURNAL HEATING...LOCAL EFFECTS AND
THE UPPER TROUGH STILL OVER HISPANIOLA.

THIS GENERAL PATTERN IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL
DAYS WITH THE EXCEPTION OF THE UPPER TROUGH WHICH IS EXPECTED TO
FLATTEN OUT BY THURSDAY...WHICH MEANS THAT THERE WILL NOT BE AS
MUCH UPPER LEVEL SUPPORT FOR PROLONGED SHOWERS AND THUNDERSTORMS.
HAVING SAID THAT...THE MOISTURE THAT IS EXPECTED WILL BE ENOUGH TO
CAUSE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN THE
AFTERNOON HOURS WHEN IT COMBINES WITH DIURNAL HEATING AND LOCAL
EFFECTS. THE GFS MODELS SEEM TO FAVOR A BIT MORE INSTABILITY FOR
THE WEEKEND WITH JUST AS MUCH MOISTURE AVAILABLE...SO SHOWERS AND
THUNDERSTORMS WOULD CONTINUE THROUGH THE WEEKEND IF THE MODEL IS
CORRECT.


&&

.AVIATION...VFR CONDS ARE EXPECTED TO PREVAIL THROUGH THE FORECAST
PERIOD WITH THE EXCEPTION OF TJMZ WHICH CAN OBSERVE MVFR CONDS
AFTER 11/17Z AS SHRA/TSRA DEVELOP OVER WESTERN PR. VCSH ACROSS
MOST OF THE LOCAL TERMINALS THROUGH THE DAY...POSSIBLY AFFECTING
THE TERMINALS DIRECTLY FOR BRIEF PERIODS. WINDS GENERALLY FROM THE
EAST AT 10-15KT WITH SEA BREEZE VARIATIONS AFTER 11/13Z.


&&

.MARINE...SMALL CRAFT OPERATORS SHOULD EXERCISE CAUTION ACROSS
THE ATLANTIC WATERS DUE TO SEAS UP TO 6 FEET AND WINDS AT 15 TO 20
KNOTS...ELSEWHERE EXPECT SEAS BELOW 5 FEET. THERE IS A MODERATE
RISK OF RIP CURRENTS ACROSS NORTHERN PR AND AROUND VIEQUES AND
CULEBRA AS WELL AS AROUND SAINT CROIX.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 88 76 / 40 10 20 30
STT 87 77 86 76 / 40 20 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
203 PM AST WED MAY 11 2016

.SYNOPSIS...At upper levels...A trough over Haiti is generating
thunderstorms there. It will move over the Dominican Republic on
Thursday while weakening. A weak branch of the sub tropical jet
will continue over the local area until Friday with the main jet
within 3 degrees latitude through mid week next week.

At mid levels...A weak north-south trough over the area will
divide the high extending across the Caribbean Sea until Friday.
High pressure then continues over the area through mid week next
week. Modest moisture persists at mid levels punctuated by good
moisture on Sunday.

at lower levels...High pressure over the sub tropical Atlantic
will build over the eastern Atlantic Ocean to maintain moderate
east southeast flow over the area. An area of moisture will
approach the area from the southeast tonight and move west across
the Caribbean Sea tomorrow. Moisture will continue through Sunday
with a brief minimum tomorrow morning. moisture then gradually
diminishes through Friday.

&&

.DISCUSSION...showers developed in the interior of puerto rico and
moved west across the island leaving up to four tenths of an inch
in the last 6 hours, with the highest amounts in eastern Puerto
Rico. moisture will diminish soon as the back edge of the moisture
moves across Puerto Rico. Another patch of moisture is east
southeast of the area and its center will pass mainly over our
local caribbean waters and just to the south. Nevertheless showers
and thunderstorms will develop in moderately unstable air over
interior and will favor the Cordillera Central and the west and
northwest portions of Puerto Rico. Saint Thomas and Saint John
will be on the fringe of this moisture but Saint Croix will have
better chances of rain tonight and Thursday.

&&

.AVIATION...Mostly VFR conditions are expected to prevail across
most of the local flying area this afternoon with vcsh across TJSJ and
TJPS. TJMZ can observe MVFR conditions after 11/18z as SHRA/TSRA develop
over western Puerto Rico. Winds generally from the east at 10 to
15 mph with seas breeze variations until 11/21Z.


&&

.MARINE...Little change for now. Winds and seas will continue to
diminish until Saturday, then winds will increase somewhat and
sea are expected to return to 4 to 6 feet...mainly in the
Atlantic.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 88 76 / 40 10 20 30
STT 87 77 86 76 / 40 20 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
520 AM AST THU MAY 12 2016

.SYNOPSIS...Weakening upper level trough is expected to erode
later today which will diminish the dynamics for long lasting
thunderstorms. However...available moisture is expected to
increase significantly during the time of max heating. This may
result in scattered to numerous showers and a few thunderstorms in
the afternoon hours. Thunderstorms are especially possible across
portions of PR while the USVI may observe scattered showers.
Available moisture will remain above normal for the next several
days...which will cause showers and thunderstorms when combined
with diurnal heating and local effects.

&&

.DISCUSSION...Fair weather prevailed across the local area through
the overnight hours. A few brief showers were observed over the
waters but land areas remained mainly dry. There is an area of
deeper moisture moving in today...which will cause an increase in
shower activity...especially in the afternoon hours. Scattered
showers...some of them moderate are possible across the local
waters and the USVI today. For PR the afternoon showers could have
a few thunderstorms. The latest high resolution models significant
rain across most of PR with the exception of the extreme NW and SW
sections of PR. The available moisture is expected to increase to
levels above normal with over 2 inches of PW forecast by the GFS
model.

Even though the upper level trough is expected to weaken
considerably by tonight...the deep moisture will stay with us for
the next several days...possibly into the weekend...which means
that we could very easily have significant rain somewhere in the
forecast area...particularly across eastern PR and the USVI in the
overnight and morning hours...then across the interior and western
sections of PR in the afternoons.

&&

.AVIATION...Prevailing VFR conditions are expected across most
of the local terminals for the next 24 hours. However...passing
shra can be expected ovr coastal waters btw ern pr and nrn
Leewards Islands...possibly causing vcsh across ISX and IST. SFC wnds
fm E 10-15 kts with sea breeze variations expected after 12/14z.


&&

.MARINE...Mariners can expect seas up to 6 feet and easterly winds
up to 20 knots across the local waters. Therefore...small craft
operators should exercise caution across most of the local waters.
Marine conditions are expected to improve during the weekend...
however showers and thunderstorms may produce brief hazardous
marine conditions.


&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
201 PM AST THU MAY 12 2016

.SYNOPSIS...Upper level trough will continue to weakens tonight
and tomorrow diminishing the dynamics for long lasting
thunderstorms. However...the above normal available moisture in
combination with daytime heating and local effects will result in
scattered to numerous showers and a few thunderstorms during the
afternoons for the next several days.

&&

.DISCUSSION...Fair weather prevailed over Puerto Rico so far this
afternoon. However...Doppler weather radar indicated isolated to
scattered showers across the Caribbean waters with few of them
affecting St Croix from time to time this afternoon. Scattered
showers and a couple of thunderstorms are still possible across
parts of the local waters...interior and western sections of
puerto rico late this afternoon. A surface trough across the
eastern Caribbean will increase the available moisture to levels
above normal with over 2 inches of PW forecast by the GFS model
Friday and Saturday.

Even though the upper level trough is expected to weaken
considerably tonight...the deep moisture will stay with us for
the next several days...possibly into the weekend...which means
that we could very easily have significant rain somewhere in the
forecast area...particularly across eastern PR and the USVI in the
overnight and morning hours...then across the interior and western
sections of PR in the afternoons.

&&

.AVIATION...Mostly VFR cond are expected across most of the local
terminals for the rest of the forecast period. Passing shra can
be expected over TISX and TJSJ. VCTS pos at TJMZ and TJBQ btw
12/18z-12/22z with Mountain obscuration across interior PR. 12/12z
sounding indicated SFC wnds from E 10-20 kts with sea breeze
variations.

&&

.MARINE...Mariners can expect seas up to 5 feet and easterly
winds up to 20 knots across the local waters. Therefore...small
craft operators should exercise caution across parts of the local
waters. A relatively quiet marine conditions are expected to
continue friday and during the upcoming weekend... however
showers and thunderstorms may produce brief hazardous marine
conditions.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 87 76 89 / 30 50 40 50
STT 77 86 77 86 / 40 50 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
448 AM AST FRI MAY 13 2016

.SYNOPSIS...At upper levels...a high pressure ridge east of the
Lesser Antilles is inducing a west-southwest flow aloft. A mid
level ridge is forecast to develop and expand westward over the
Eastern Caribbean during the weekend. At low levels...weak high
pressure north of the local region will merge with another high
pressure over the Central Atlantic over the next few days. This
surface high pressure will remain near stationary as builds over
the Central Atlantic...resulting in breezy conditions across the
islands Tuesday and Wednesday.

&&

.DISCUSSION...Plenty of moisture remains across the forecast area
today. Precipitable Water Analysis from CIMSS indicated deep
moisture just upstream of the local islands. This high moisture
content will keep the atmosphere fairly unstable especially at low
to mid levels. As a result...showers and thunderstorms will
likely develop across portions of PR and the USVI throughout the
day. The heaviest showers are expected over the interior...north
and northwest PR as a moderate southeasterly flow prevails below
700 MB.

Although...moisture will remain higher than normal through sunday...
no synoptic forcing will be presented to support organized
convection. A mid level ridge will dominate the Eastern Caribbean
Basin. Therefore...partly cloudy to mostly cloudy skies with
scattered showers are likely during the weekend. A drier and more
stable air mass is forecast to encompass the local area between
monday and wednesday...reducing the coverage of showers across the
forecast area.

Then...an upper level trough will amplify over the Northeast
Caribbean Region Thursday and Friday...increasing again the
potential of showers and thunderstorms across the local islands.

&&

.AVIATION...SHRA and TSRA will continue over the waters thru the
fcst period. Mainly -RA/RA can briefly affect TNCM/TKPK and the
USVI/Eastern PR terminals thru the morning hours. Mtn top obscd
across E PR will likely continue thru this afternoon...spreading
across the rest of mainland PR as SHRA/TSRA develops over the
interior/nw sections. MVFR to brief IFR conds possible at
TJSJ/TJBQ/TJMZ from 18z-22z. Low level winds will continue from the
E-ESE at 10-15 kt with sea breeze variations aft 13z.


&&

.MARINE...A small Northeast swell of around 4 feet will invade
the local waters later today. This swell will help to maintain the
seas around 3-5 feet across most of the waters. Moderate winds
will continue through monday...increasing to locally fresh between
tuesday and friday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 89 77 / 50 40 40 20
STT 87 78 86 78 / 40 40 40 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
204 PM AST FRI MAY 13 2016

.SYNOPSIS...a high pressure ridge centered to east of the Lesser
Antilles will continue to produce a west-southwest wind flow
aloft. A mid level ridge is forecast to develop and expand
westward over the Eastern Caribbean during the weekend. weak high
pressure north of the local region will merge with another high
pressure over the Central Atlantic over the next few days. This
feature will result in breezy conditions across the islands
Tuesday and Wednesday.

&&

.DISCUSSION...abundant moisture will remain across the local
islands tonight and during the rest of the weekend. Precipitable
Water will remain near or above 2.00 inches for the next several
days decreasing to well below 2.00 inches on Tuesday next week. This
high moisture content will keep the atmosphere fairly unstable
at low to mid levels. As a result...showers and thunderstorms
are expected to develop across portions of PR and the USVI
this afternoon and early this evening.

Even though moisture content will remain high for the next
several days...no synoptic forcing will be presented to support
organized convection. however...partly cloudy to mostly cloudy
skies with scattered showers are expected across eastern sections
of Puerto Rico...Vieques...Culebra and USVI each night...followed
by scattered showers and a couple of thunderstorms across western
and interior sections of puerto rico each afternoon. A drier and more
stable air mass is forecast to encompass the local area between
monday and wednesday...reducing the coverage of showers across the
forecast area.

&&

.AVIATION...only VCSH expected at TNCM/TKPK/TIST and TISX
terminals thru the rest of the afternoon and evening hours.
SHRA/TSRA are expected to develop north of Cordillera Central
this afternoon...inducing periods of MVFR across TJSJ/TJMZ and
TJBQ until 13/22Z. Therefore...Mtn obscuration across expected
over interior and NW sections. Low level winds will continue from
the E-ESE at 10-15 kt with sea breeze variations.

&&

.MARINE...Relatively quiet marine conditions are expected for
the next few days...with seas up to 5 feet and east southeast
winds up to 20 knots across the local waters. However showers and
thunderstorms may produce brief hazardous marine conditions.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 89 77 88 / 40 40 20 20
STT 78 86 78 86 / 40 40 50 50

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
519 AM AST SAT MAY 14 2016

.SYNOPSIS...Mid level ridge is forecast to develop and expand
over the Eastern Caribbean through early next week. At low levels...
areas of high pressure will merge and build over the Central
Atlantic over the next few days. This surface high pressure will
remain near stationary as builds over the Central Atlantic...
resulting in breezy conditions across the islands Tuesday and
Wednesday.

&&

.DISCUSSION...High moisture content during the weekend will keep
the atmosphere fairly unstable. As a result...showers and
thunderstorms will likely develop across portions of PR and the
USVI throughout the day. The heaviest shower activity is expected
this afternoon over the interior...north and northwest Puerto
Rico. Moderate east to southeast flow will keep the heat index
near 100 degrees especially in the leeward side of the islands.

Although...moisture will remain above normal through end of the
weekend...less organized convection is forecast across the islands
as a weak synoptic forcing prevails across the Northeast Caribbean
Region. Therefore...partly cloudy skies with scattered showers
and isolated thunderstorms are likely once again on Sunday.

A mid level ridge will build over the Eastern Caribbean early in
the week...bringing drier and more stable air mass to the forecast
area. As a result...the coverage of showers and thunderstorms will
diminish from Monday through at least Wednesday.

Then...An upper level trough will amplify over the Northeast Caribbean
Region Thursday and Friday...increasing again the potential of showers
and thunderstorms across the local islands.

&&

.AVIATION...Mainly VFR conditions expected through the forecast
period. However...trade wind showers will continue en route from
the leeward islands across both Atlantic and Caribbean waters.
They could briefly affect the USVI/Eastern PR terminals thru the
morning hours. Max tops around FL200. Between 17z-22z...SHRA/TSRA
expected once again along the N/NW quadrant of PR...impacting
mainly the flying area of TJBQ/TJMZ. VCSH elsewhere. Mtn top obscd
likely with the SHRA/TSRA. Low level winds will continue ESE at
10- 15 kt...with sea breeze variations at JMZ/JBQ after 14z.

&&

.MARINE...A moderate northeast swell of around 4 feet will invade
the local waters later today. This swell will increase the size of
the breaking waves as well as the risk of rip current. Moderate
winds will continue through monday...increasing to locally fresh
between Tuesday and Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 89 77 / 40 20 40 20
STT 87 78 86 78 / 30 50 50 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
259 PM AST SAT MAY 14 2016

.SYNOPSIS...At upper levels...High pressure dominates the
Caribbean and Tropical Atlantic Oceans. a weak short wave will
move across the area Monday night and dig into the western Tropical
Atlantic. Then high pressure will build over the western
Caribbean. The trough will regress back over Puerto Rico over the
following weekend.

At mid levels...High pressure over the western Tropical Atlantic
will move over the Caribbean Sea early in the week. High pressure
over the area will be divided to the east and west by a weak
trough late in the week...but this may be overwhelmed by the
approach of a cut-off low over the southeastern United States
early next week that will cause troughing in the western
Caribbean.

At lower levels...High pressure in the central Atlantic will shift
east northeast toward the Azores during the upcoming week. When
high pressure returns to the central Atlantic next week low
pressure may begin forming over the coastal waters off the
southeastern United States early next week.

&&

.DISCUSSION...Although stability continues over the area, upper
level divergence has decreased to a minimal amount and that
centered over northwest Puerto Rico. Confirming this, we have
seen some activity with tops exceeding only 20 kft. As of mid
afternoon lighting had not been observed in the area. A similar
situation will occur on Sunday with development again over
northwest Puerto Rico. Moisture drops considerably overnight on
Sunday into Monday and shower activity is forecast to decrease
everywhere. Moisture then rises only slowly through Friday
afternoon. With only weak troughing at upper levels and northwest
flow aloft Tuesday through Thursday, shower and thunderstorm
activity will be mainly benign...although some may be locally
strong, being unopposed by any inversion after Monday. However
the addition of moisture on Friday and continued cool temperatures
at mid levels...possibly as low as minus 9 degrees C at 500
mb...means that shower and thunderstorm activity should increase
and become considerably stronger. This would likely result in
urban and small stream flooding and frequent lightning and
possibly some strong gusty winds in the area of thunderstorms.
Conditions improve over the weekend, although little confidence is
placed in the GFS beyond Friday.


&&

.AVIATION...Mainly VFR conditions should continue through
15/18z. SHRA/TSRA expected once again along the N/NW quadrant of
PR...impacting mainly the terminals of TJBQ/TJMZ. VCSH elsewhere.
Mtn tops obscd likely with the SHRA/TSRA. Trade wind showers are
expected again tonight from the leeward islands eastward across
both Atlantic and Caribbean waters. They could briefly affect the
USVI/Eastern PR terminals thru the morning hours. Low level winds
will continue ESE at 10-15 kt...with sea breeze variations at
JMZ/JBQ after 18z to 22z.


&&

.MARINE...Northeast swell of about 14 seconds has reached the
near shore buoy. This swell at buoy 41043 was only 3 feet where
wave heights were 5 feet. Wind waves are easterly at this time.
seas are expected to change little through tuesday in the Atlantic
and rise very slowly in the Caribbean. The rip current risk should
remain high due to the swell at least through Sunday afternoon.
This is mainly due to the stronger trade winds and the addition of
the northeast swell, which is why the eastern end of Saint Croix
is also indicated. We will extend the CFW for high risk of Rip
Currents later this afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 76 89 / 30 40 20 20
STT 79 86 78 88 / 40 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
520 AM AST SUN MAY 15 2016

.SYNOPSIS...Mid level ridge is forecast will expand over the
Eastern Caribbean during the next few days. At low levels...
high pressure will build over the Central Atlantic...inducing a
moderate to fresh southeasterly flow across the local islands. A
relatively stable pattern will prevail through midweek. Then an
upper level trough will swing across the region late in the week...
allowing moisture and instability to pool over the area.

&&

.DISCUSSION...Available moisture will gradually diminish across
the area through Tuesday. Weak synoptic forcing combined with
below-normal moisture will likely result in less organized convection
across the islands over the next few days. However...Some showers
are still expected each afternoon across the northwest quadrant of
Puerto Rico due to the sea breeze convergence. East to southeast
flow will keep the max temperatures around 90 degrees especially
across portions of north and west Puerto Rico.

A mid level ridge will dominate the Eastern Caribbean the first
half of the week...bringing a drier and more stable air mass over
he forecast area. As a result...the coverage of showers will be
mainly isolated to scattered.

Then...weather conditions will change somewhat as an upper level
trough crosses the Northeast Caribbean Region between Thursday
and Friday. This will likely increase the potential of showers
and thunderstorms across the local islands.

&&

.AVIATION...Mainly VFR conds will prevail. -SHRA can affect eastern
PR thru 12z creating mvfr cigs and mtn obscurations. Then SHRA/TSRA
are expected to dvlp over NW PR btw 16z-22Z...impacting mainly
JBQ/JMZ. Sfc winds E-ESE 10-15 kts with sea breeze variations aft
14z.

&&

.MARINE...Moderate winds will continue through monday...increasing
to locally fresh between Tuesday and Wednesday. Seas of 3-5 feet will
prevail over the next several days. As a result...no Small Craft
Advisories are anticipated during the next 5-7 days.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 89 79 / 20 10 10 20
STT 88 79 88 78 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
153 PM AST SUN MAY 15 2016

.SYNOPSIS...A mid to upper level ridge is forecast to remain over
the Eastern Caribbean until the middle of the week. Strong surface
high across the Central Atlantic will continue to produce a
moderate to fresh southeasterly wind flow across the local
islands. An upper level trough will move across the region
Thursday and Friday...inducing an increase in moisture and
instability across the northeast Caribbean.

&&

.DISCUSSION...Isolated to scattered showers persisted across
eastern sections of Puerto Rico and across the Caribbean waters
during the morning hours. By noon...scattered showers and isolated
thunderstorms started to develop across interior and northwest
sections of Puerto Rico. This activity is expected to continue
until the sunset.

A similar weather pattern is expected to continue across the
forecast area until the middle of the week. A mid to upper level
ridge will continue to inhibit widespread thunderstorms
development across the local islands through at least Wednesday.
However...the moisture embedded in the trades is forecast to
produce some showers across eastern PR...Vieques...Culebra and
USVI during the nights and early in the mornings...followed by
scattered showers and a couple of thunderstorms due to the
combination of daytime heating and local effects across interior
and western sections of Puerto Rico each afternoon. However...not
widespread or significant precipitation is expected. By thursday a
week mid to upper level trough will move across the region...
inducing an increase in moisture transport with the potential of
thunderstorms across the region.

&&

.AVIATION...Mainly VFR conditions will prevail across most of the
local flying area during the forecast period. SHRA/TSRA will
continue to develop over NW PR until 22Z creating MVFR or EVEN IFR
conditions and mtn obscurations across TJBQ/TJMZ. Sfc winds will
remain from E-ESE at 10-15 kts increasing slightly after 16/12z.

&&

.MARINE...Seas up to 5 feet and winds up to 20 knots are expected
to continue across the local waters through Monday. As a
result...Small Craft Advisories are urged to exercise caution.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 79 89 / 10 10 20 20
STT 79 88 78 88 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
533 AM AST MON MAY 16 2016

.SYNOPSIS...Surface high pressure will meander across the central
Atlantic through the end of the week. This will continue to
generate a moderate to fresh easterly wind flow across the local
islands. Mid-level high pressure will continue over the Caribbean
basin through late mid-week...resulting in drier air aloft. Upper
ridge over the southeastern Caribbean will weaken during the next
day or so. Upper level short wave trof will move over the area
late in the work week. PWAT increases thu-fri over the forecast
area.


&&

.DISCUSSION...Mostly clear to partly cloudy skies prevailed during
the overnight hours. Quick trade wind showers were observed
across the local waters...with a few of them leaving light
rainfall amounts across the eastern sections of PR and trace
amounts over the USVI. Overall fair weather conditions should
continue through at least wednesday...with the available low level
moisture inducing some afternoon showers each day over western PR.
Trade wind showers will continue through the forecast period
across the waters and some of them will move from time to time
between the USVI and eastern PR...mainly during the overnight and
early morning hours. By the second half of the work week...the
mid to upper level ridges will erode and promote better moisture
transport and an upper level short wave trof will promote
divergence aloft. This will increase the chance for showers and
thunderstorm development over the islands.


&&

.AVIATION...Mostly VFR conds will prevail through the forecast
period. Brief MVFR conds and mtn top obscr posible ovr Western PR
this afternoon between 16/18Z-22Z. Some of these SHRA/TSRA will
affect TJMZ at times. E to ESE winds of 15-20 kts with gusts between
20-25 kts expected below FL050.


&&

.MARINE...Seas between 3 to 5 feet...increasing up to 6 feet later
tonight and winds up to 20 knots are expected across the local
waters through much of the week. As a result...small craft
operators are urged to exercise caution.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 89 77 / 20 20 20 40
STT 88 79 88 78 / 20 30 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
145 PM AST MON MAY 16 2016

.SYNOPSIS...Surface high pressure is expected to remain over the
central east Atlantic through the end of the week. This will
continue to generate a moderate to fresh easterly wind flow across
the local islands. Mid-level high pressure will continue over the
Caribbean through wednesday...which will limit instability and
convection. Upper ridge over the southeastern Caribbean will
continue to slowly weaken for the next couple of days. Upper
level short wave trough will move over the area on Thursday into
Friday. The available moisture is a bit below average today and it
is expected to remain at or below normal through Wednesday...then
on Thursday and Friday the moisture is expected to increase to
above normal levels.

&&

.DISCUSSION...The dry air advection combined with the ridge in the
mid and upper levels has really limited the shower activity
through the forecast area today. With the exception with a few
brief showers moving in with the trades and some showers streamingoff
the USVI...the has been very little to no shower activity. Having
said that...there is sea breeze convergence across the extreme NW
sections of PR which could produce some showers later in the
afternoon as daytime heating and the sea breeze convergence
combine with the limited available moisture. There is also a
streamer developing from the Luquillo Mountain Range...and visible
in satellite imagery...across portions of the San Juan metro area.
This streamer may cause some shower activity later on in the
afternoon across portions of the San Juan metro.

The local weather is expected to remain fairly quiet for the next
couple of days as the available moisture remains somewhat limited
and the atmosphere is stable with the mid to upper level ridges.
Locally induced showers are still possible in the afternoons but
these would be expected to be relatively shallow. Moisture
increases on Thursday and Friday and a shortwave trough in the
upper levels is expected to approach the local area. This will
give way to a higher chance of showers and possible thunderstorms
across the local area on those days...especially in the afternoon
hours as far as thunderstorms go. Morning brief showers across the
local waters...USVI...and eastern PR could be expected late this
workweek as the moisture moves in.


&&

.AVIATION...VFR conds to prevail across most of the TAF sites.
Afternoon convection sill expected across the NW PR...and some
-SHRA/SHRA can move over TJMZ/TJBQ. Mountain obscuration over the
interior of PR and SCT-BKN ceilings...btwn FL030-FL050 are
expected across this sites. Brief -SHRA are possible at
TJSJ/TIST/TISX btwn 17/00z-14z. The sounding data had sfc winds
from the E-ESE 11-21 kts. Sfc obs reported sea breeze variations
at this sites. Aft 16/23z expect E-ESE winds at 5-10 kts.


&&

.MARINE...Small craft should exercise caution as winds will be up
to 20 knots across the surrounding offshore waters and local
passages. Seas will be up to 5 feet for the rest of
today...increasing slightly to up to 6 feet tonight.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 77 88 / 30 30 40 40
STT 79 88 78 85 / 30 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
540 AM AST TUE MAY 17 2016

.SYNOPSIS...Surface high pressure will continue across the
central Atlantic through the end of the week. This will continue
to generate a moderate to locally fresh trades across the local
islands. Mid to upper level ridge will continue over the
Caribbean basin through late mid-week...resulting in drier air
aloft. Upper level short wave trof will move over the area late
in the work week. Moisture increases later in the week cross the
forecast area.


&&

.DISCUSSION...Brisk trade wind showers continued during the
overnight into early Tuesday morning across the forecast area.
Rainfall amounts were generally between 0.10-0.30 in. Mainly
across the northeast sections of PR. Trade wind showers will
continue through the forecast period between the USVI and eastern
PR...mainly during the overnight and early morning hours. Shallow
afternoon convection is expected mainly over western PR. Late in
the week as the mid to upper level ridge erodes...better moisture
transport is expected. Another short wave trof is expected to move
from the west during the weekend...followed by a deeper upper trof
by early next week. This will increase cloudiness and the chance
for showers and thunderstorm across the forecast area.

&&

.AVIATION...Mostly VFR conds will prevail through the forecast
period. Brief MVFR conds and mtn top obscr posible ovr Western PR
this afternoon. Some of these SHRA/TSRA will affect TJMZ and TJBQ
between 17/18Z-22Z. E to ESE winds of 15-20 kts with gust between 20-
25 kts expected below FL100.


&&

.MARINE...Moderate to locally fresh trade winds will continue
across all local waters. Local buoys are indicating east winds
around 15 knots and seas at 4-5 feet...except at Rincon were they
are less than 2 feet. Small crafts should continue to exercise
caution as winds up to 20 knots are expected.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 89 78 / 30 20 20 20
STT 88 79 87 78 / 30 30 30 30