Caribbean - Central America Weather

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
141 PM AST THU APR 28 2016

.SYNOPSIS...A BROAD UPPER LEVEL TROUGH ACROSS THE WESTERN
ATLANTIC TO THE NORTHERN CARIBBEAN WILL CONTINUE TO MAINTAIN A
DIVERGENT PATTERN ACROSS THE FORECAST AREA DURING THE NEXT SEVERAL
DAYS...AS UPPER LEVEL PERTURBATIONS MOVE OVER THE ISLANDS FROM
TIME TO TIME. AT LOWER LEVELS...INDUCED SURFACE TROUGH ACROSS
THE WATERS NORTH OF HISPANIOLA AND SURFACE HIGH TO THE NORTHEAST
OF THE REGION WILL PROMOTE A SOUTHEASTERLY WIND FLOW THROUGH MUCH
OF THE FORECAST PERIOD. SAHARAN DUST WILL CONTINUE ACROSS THE AREA
AT LEAST UNTIL SATURDAY.

&&

.DISCUSSION...THROUGH THE MORNING HOURS UNTIL NOW...A CLUSTER OF
THUNDERSTORMS HAVE REDEVELOP OVER THE CARIBBEAN WATERS TO THE
SOUTH OF VIEQUES AND ST. CROIX. THIS IS DUE TO THE POSITION OF THE
UPPER TROF AXIS AND A 90+ KT JET ABOVE 200 MB AS INDICATED BY THE
28/12Z TJSJ UPPER AIR SOUNDING. THIS UPPER LEVEL PERTURBATION
WILL CONTINUE TO LIFT TO THE NORTHEAST TODAY...HOWEVER...DIURNALLY
INDUCED AFTERNOON SHOWERS AND THUNDERSTORMS WILL BE ENHANCED BY
FAVORABLE UPPER LEVEL DYNAMICS ACROSS THE MTN RANGES OF PR AND
SLOWLY DRIFT TO THE NORTH-NORTHWEST AS STEERING WINDS PREVAIL
FROM THE SOUTH. ALSO...DRIER AIR BETWEEN 600-500 MB AND LOW
TEMPS(-9.5C) AT 500 MB COULD CREATE SMALL HAIL AND/OR STRONG GUSTY
WINDS AT THE SURFACE WITH THE THUNDERSTORMS THIS AFTERNOON.

TROUGHINESS ALOFT WILL MAINTAIN FAVORABLE CONDITIONS
FOR THE DEVELOPMENT OF SHOWERS AND STRONG THUNDERSTORMS THROUGH
EARLY NEXT WEEK. AS UPPER LEVEL SHORT WAVE VERTICES MOVE ACROSS
THE FORECAST AREA DURING THE WEEKEND AND EARLY NEXT WEEK...THIS
WILL ENHANCE RAINFALL AND THUNDERSTORM ACTIVITY OVER THE INTERIOR
AND THE NORTH/EASTERN SIDE OF THE ISLAND. FRIDAY/SATURDAY SEEMS TO
BE THE NEXT ACTIVE WEATHER DAY WITH DEEPER SHORT WAVE MOVING ALOFT
AND BETTER LOW LEVEL MOISTURE POOLING ACROSS THE AREA. ANOTHER
SHORT WAVE TROF MOVES ON MONDAY ENHANCING CONVECTION ONCE AGAIN.
DUE TO ALREADY SATURATED SOILS...ANY ADDITIONAL HEAVY RAINFALL WILL
LEAD TO URBAN AND SMALL STREAM/RIVER FLOODING. ALSO...LOCALIZED FLASH
FLOODING AND MUDSLIDES CANT BE RULED OUT EACH AFTERNOON.

&&

.AVIATION...MVFR CONDS WILL REMAIN POSSIBLE THROUGH AT LEAST 28/22Z
AT TJMZ/TJBQ AND POSSIBLY TJSJ TERMINALS IN SHRA/TSRA. MOUNTAIN
OBSCURATION ACROSS THE INTERIOR OF PR. MOSTLY VFR COND FOR THE REST
OF THE AREA. LOW LEVEL WINDS 5-15 KT FROM THE SE...BECOMING LIGHT
AND VARIABLE OVERNIGHT.


&&

.MARINE...LATEST BUOY READINGS INDICATE THAT THE NORTHERLY SWELL
IS SLOWLY FADING AND MODEL GUIDANCE SUGGEST THE SAME WITH
WAVE HEIGHTS AROUND 4 FEET AT 10 SECONDS. SEAS WILL REMAIN
GENERALLY BELOW 6 FEET ACROSS ALL LOCAL WATERS DURING THE NEXT
SEVERAL DAYS. UNSETTLED WEATHER CONDITIONS WILL CONTINUE ACROSS
THE REGIONAL WATERS INTO EARLY NEXT WEEK AS THUNDERSTORMS ARE
FORECAST TO DEVELOP OVER THE WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 88 75 88 / 40 50 40 40
STT 76 83 76 83 / 50 50 40 40

&&

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
522 AM AST FRI APR 29 2016

.SYNOPSIS...AT UPPER LEVELS...A SHORT WAVE WILL DEVELOP OVER THE
WINDWARD PASSAGE ON SATURDAY AND MOVE ACROSS THE AREA ON SUNDAY
AFTERNOON. A SECOND AND WEAKER SHORT WAVE WILL PASS THROUGH ON
MONDAY. HIGH PRESSURE WILL BEGIN TO RIDGE OVER THE ANEGADA PASSAGE
BY MID WEEK. THEN IT WILL MOVE SLIGHTLY EAST AND STRENGTHEN.

AT MID LEVELS...A WEAK LOW WILL FORM NORTH OF THE DOMINICAN
REPUBLIC ON SATURDAY. ALTHOUGH IT DISSOLVES ON SUNDAY...WEAK
TROUGHING CONTINUES OVER THE WINDWARD PASSAGE AND HISPANIOLA
THROUGH MID WEEK. MID LEVEL MOISTURE INCREASES TODAY AND SATURDAY
AND THEN AGAIN EARLY NEXT WEEK. MOIST SOUTHERLY FLOW RETURNS THE
FOLLOWING WEEKEND AFTER A BRIEF RESPITE.

AT LOWER LEVELS...HIGH PRESSURE CONTINUES NORTHEAST OF THE
AREA...WHILE LOW PRESSURE REMAINS IN THE SOUTHWEST AND SOUTHERN
CARIBBEAN. HIGH PRESSURE BUILDS AGAIN OVER THE NORTHEAST CENTRAL
ATLANTIC LATE NEXT WEEK. UNSETTLED WEATHER WILL CONTINUE THROUGH
AT LEAST WEDNESDAY.

&&

.DISCUSSION...THUNDERSTORMS WITH FREQUENT LIGHTNING RE-DEVELOPED
IN THE ATLANTIC AND CONTINUED WITH HEAVY RAIN THROUGH THE REST OF
THE NIGHT. SHOWERS ALSO DEVELOPED SOUTH OF PONCE WITH OCCASIONAL
LIGHTNING AND THEN MOVED NORTH...EVENTUALLY BRINGING SIGNIFICANT
RAINFALL TO MUCH OF THE SOUTH COAST SOUTH OF THE CORDILLERA FROM
GUAYANILLA TO MAUNABO. SOME OF THE SHOWERS PERSISTED AND MOVED
ACROSS SABANA GRANDE TO LAS MARIAS. GOOD MOISTURE WITH HIGH
PRECIPITABLE WATER VALUES WILL CONTINUE OVER THE AREA TODAY. THE
CURRENT GFS SHOWS A MINIMUM IN THE UPPER LEVEL DIVERGENCE OVER THE
AREA AT 29/18Z...BUT AREAS OF DIVERGENCE MOVE BACK OVER THE AREA
IN THE WESTERLY FLOW BY 30/00Z. THIS SUGGESTS THAT CONVECTION THAT
DEVELOPS DESPITE THE RESISTANCE FROM THE UPPER LEVELS MAY CONTINUE
LATER INTO THE NIGHT TONIGHT. CURRENT INDICATIONS FROM THE
SOUTHEASTERLY FLOW IS THAT THUNDERSTORMS WILL RE-DEVELOP IN
WESTERN AND NORTHWESTERN PUERTO RICO THIS AFTERNOON. URBAN AND
SMALL STREAM FLOODING IS ALSO INDICATED IN NORTHWEST PUERTO RICO
AGAIN TODAY. SATELLITE IMAGERY SUGGESTS THAT THE HIGH CLOUDS WILL
DIMINISH DURING THE MORNING AND ALLOW CONSIDERABLE HAZY SUNSHINE
TO MAKE IT THROUGH TO BOOST THE INSTABILITY AGAIN. THE NASA GEOS-5
DUST MODEL ALSO SHOWS SAHARAN DUST PERSISTING THROUGH THE DAY TO
LIMIT VISIBILITIES TO 10 TO 15 MILES. MOISTURE IMPROVES SATURDAY
EVEN IF DYNAMICS DO NOT AND EXPECT ANOTHER ROUND OF HEAVY SHOWERS
AND THUNDERSTORMS WITH SIMILAR URBAN AND SMALL STREAM FLOODING.
SUNDAY LOOKS SIMILAR ALTHOUGH SLIGHTLY LESS ACTIVE. THEN MOISTURE
INCREASES THROUGH WEDNESDAY. AT THIS TIME THE GFS INDICATES THAT
THERE MAY BE LESS STRONG VERTICAL MOTION IN THE PROFILE EARLY NEXT
WEEK. NEVERTHELESS...FLOW WILL CONTINUE FROM THE SOUTHEAST AND
WILL BE LOADED WITH MOISTURE TO CREATE AMPLE SHOWERS AND
THUNDERSTORMS THAT WILL BE MOST PREVALENT OVER NORTHWEST PUERTO
RICO.

&&

.AVIATION...MOISTURE ALONG WITH UNSTABLE CONDITIONS WILL CONTINUE TO
PRODUCE SHRA/TSRA OVER THE SURROUNDING ATLANTIC AND CARIBBEAN
WATERS SOME OF THEM WILL MOVE INLAND AFFECTING THE COASTAL SECTIONS.
-SHRA/SHRA WILL REMAIN POSSIBLE ONCE AGAIN AT TJPS/TISX/TNCM/TKPK
EARLY THIS MORNING. DURING THE AFTERNOON...MOUNTAIN OBSCURATIONS
ARE EXPECTED ACROSS THE INTERIOR OF PR WITH SHRA/TSRA POSSIBLE AT
TJMZ/TJBQ/TJSJ BETWEEN 29/17Z-30/02Z. CALM TO LIGHT AND VARIABLE
WINDS...BECOMING FROM THE SE AT 10 TO 15 KT AFTER 29/12Z.

&&

.MARINE...WITH WINDS THAT CHANGE LITTLE DURING THE NEXT 4 TO 5
DAYS AND NORTHEASTERLY SWELL THAT SLOWLY DIMINISHES...SEAS WILL
CONTINUE AT 4 TO 6 FEET IN THE OUTER ATLANTIC AND A LITTLE LESS IN
THE CARIBBEAN. SMALL CRAFT ADVISORIES ARE NOT EXPECTED SINCE
NORTHERLY SWELL DOES NOT INCREASE MUCH ABOVE 4 FEET WHEN IT
REACHES THE LOCAL AREA. HOWEVER...INCREASED WINDS AND THE SWELL
NOW REACHING THE AREA WILL BRING A HIGH RISK OF RIP CURRENTS TO
PARTS OF THE NORTH COASTS OF PUERTO RICO AND CULEBRA TODAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 75 87 75 / 60 40 40 40
STT 86 78 83 75 / 30 20 40 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
243 PM AST FRI APR 29 2016

.SYNOPSIS...A SERIES OF MID TO UPPER SHORT-WAVE TROUGH WILL CONTINUE
STREAM OVER THE LOCAL REGION THROUGH NEXT WEEK. AMPLE AREA OF
MOISTURE WILL REMAIN OVER THE NORTHEAST CARIBBEAN REGION OVER THE
NEXT SEVERAL DAYS. AS A RESULT...HIGHLY UNSTABLE AND MOIST
ATMOSPHERE REMAINS OVER THE FORECAST AREA...FAVORING THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS EVERYDAY. UNSETTLED
PATTERN WILL LIKELY PREVAIL UNTIL AT LEAST MIDWEEK NEXT WEEK.

&&

.DISCUSSION...VERY UNSTABLE AND MOIST AIR MASS OVER THE FORECAST
AREA HAVE RESULTED IN THE DEVELOPMENT SHOWERS AND THUNDERSTORMS
WITH HEAVY RAINFALL ACROSS PORTIONS OF PUERTO RICO. THE HEAVIEST
RAINFALL OCCURRED IN PORTIONS OF EAST...NORTHEAST AND NORTH
CENTRAL PUERTO RICO. AREAS OF FAJARDO...LUQUILLO AND CEIBA
RECEIVED IN EXCESS OF 3 INCHES AND CONTINUED TO RAIN. OTHER AREAS
OF THE WEST AND NORTH PR EXPERIENCED AT LEAST ONE INCH OF RAIN SO
FAR THIS AFTERNOON. NEW SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
DEVELOP ACROSS PORTIONS OF THE EASTERN THIRD OF PUERTO RICO
THROUGH THIS EVENING.

VERY MOIST SOUTHEASTERLY FLOW ACROSS THE EASTERN CARIBBEAN WILL
CONTINUE TO PROMOTE MOISTURE CONVERGENCE ACROSS PUERTO RICO AND
THE US VIRGIN ISLANDS THROUGH THE END OF THE WEEK. THIS COMBINES
WITH INFLOW OF MID LEVEL ENERGY AND FAVORABLE JET DYNAMICS TO SUSTAIN
UNSETTLED CONDITIONS OVER THE NEXT SEVERAL DAYS.

PATTERN WILL REMAIN HIGHLY FAVORABLE AND CONDUCIVE TO ORGANIZED
DEEP CONVECTION THROUGH MID-WEEK NEXT WEEK. HIGH MOISTURE CONTENT
AND ADDITIONAL PERTURBATIONS AT MID-UPPER LEVELS WILL KEEP THE
CHANCES OF SHOWERS AND THUNDERSTORMS HIGH THROUGH THE FORECAST
PERIOD.

&&

.AVIATION...UNSTABLE WEATHER CONDITIONS WILL CONTINUE TO PRODUCE
SHRA/TSRA OVER THE REGION DURING THE FORECAST PERIOD. SHRA/TSRA WILL
REMAIN POSSIBLE AT TJSJ/TJPS AND TJMZ WITH MOUNTAIN OBSCURATIONS
BETWEEN UNTIL 30/02Z. WINDS WILL CONTINUE FROM THE SE AT 10 TO 15 KT.

&&

.MARINE...WINDS OF 10-15 KT AND SEAS OF 3-5 FEET CAN BE EXPECTED ACROSS
MOST OF THE WATERS OVER THE NEXT SEVERAL DAYS. SMALL CRAFT ADVISORIES
ARE NOT EXPECTED OVER THE NEXT 5-7 DAYS. THUNDERSTORMS ACROSS THE
WATERS WILL BE THE MAIN HAZARD THROUGH EARLY NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 87 75 88 / 20 40 40 40
STT 78 83 75 86 / 40 40 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
446 AM AST SAT APR 30 2016

.SYNOPSIS...AT UPPER LEVELS...AN AREA OF DIVERGENCE IS MOVING
ACROSS PUERTO RICO TO FAVOR STRONG CONVECTION AND HEAVY RAIN. A
TROUGH WILL FOLLOW ON SUNDAY. BUT INCOMING SHORTWAVES WILL
REINFORCE THAT TROUGH OVER THE AREA THROUGH THE EARLY PART OF THE
WEEK. A RIDGE WILL BEGIN TO BUILD OVER THE AREA LATER NEXT WEEK.

AT MID LEVELS...A WEAK LOW IS FORMING NORTH OF HAITI AND WILL MOVE
TO NORTH OF AGUADILLA BY 01/06Z. THE TROUGH WILL CONTINUE OVER
THE AREA UNTIL MONDAY. HIGH PRESSURE BUILDS OVER THE TROPICAL AND
SUBTROPICAL ATLANTIC DURING THE WEEK...BUT IS WELL AWAY FROM THE
AREA. MODERATE TO GOOD MOISTURE CONTINUES IN THE MID LEVELS UNTIL
AROUND 10 MAY.

AT LOWER LEVELS...LOW PRESSURE WILL CONTINUE IN THE SOUTHWEST AND
SOUTHERN CARIBBEAN SEA. A LOW IN THE WESTERN ATLANTIC IS PULLING A
TROUGH OVER THE DOMINICAN REPUBLIC THIS MORNING...BUT HIGH
PRESSURE WILL REPLACE IT BY EARLY NEXT WEEK. THEN DURING THE WEEK
HIGH PRESSURE WILL BUILD OVER THE NORTHEASTERN ATLANTIC AND EXTEND
SOUTHWEST TOWARD THE LOCAL AREA HOLDING MOIST SOUTHEAST FLOW OVER
THE AREA. MOISTURE IS NOT EXTREME BUT DEEP ENOUGH TO SUSTAIN
SHOWERS AND THUNDERSTORM ACTIVITY THROUGH AT LEAST THE NEXT 5
DAYS. MORE DETAILS BELOW.

&&

.DISCUSSION...AIDED BY GOOD DIVERGENCE ALOFT IN A SHORT WAVE...
SHOWERS AND THUNDERSTORMS WITH FREQUENT IN CLOUD AND CLOUD TO
WATER LIGHTNING DEVELOPED DURING THE HOURS AFTER MIDNIGHT THIS
MORNING. AT THIS TIME VIGOROUS ACTIVITY NEARLY COVERS THE MONA
CHANNEL...AND MODERATE TO HEAVY RAIN HAS SPILLED INTO WESTERN
PUERTO RICO. OTHER THUNDERSTORMS HAVE FORMED IN THE COASTAL WATERS
SOUTH OF PUERTO RICO OVERNIGHT AND MOVED INLAND. SHOWERS HAVE ALSO
BEEN FORMING IN THE AIR BEING CARRIED OVER THE ISLAND FROM THE
SOUTHEAST RESULTING IN SOME RAIN FOR AREAS OF EASTERN PUERTO RICO.
ACTIVITY IS EXPECTED TO CONTINUE IN THE MORNING AND MAY INTENSIFY
IN LOCAL AREAS DURING THE AFTERNOON. BUT IT IS BEGINNING TO LOOK
LIKE THUNDERSTORMS WILL BEGIN IN MANY PARTS OF PUERTO RICO THIS
MORNING.

THE U.S. VIRGIN ISLANDS HAVE SO FAR BEEN IN A QUIETER PART OF THE
FORECAST AREA...BUT A FEW SHOWERS ARE DEVELOPING IN THE ANEGADA
PASSAGE. CURRENT INDICATIONS ARE THAT THE FOCUS OF THE BEST
MOISTURE IS RETURNING FROM THE NORTH TO PASS OVER PUERTO RICO AND
THE U.S. VIRGIN ISLANDS DURING THE DAY AND THEN REFORM TO THE
SOUTH OF THE AREA TONIGHT. ALTHOUGH THERE IS A BREAK IN THE
DEEPEST MOISTURE ON SUNDAY AS PRECIPITABLE WATER FALLS THROUGH
SUNDAY EVENING...MOISTURE INCREASES MONDAY THROUGH FRIDAY IN THE
LATEST 30/00Z RUN OF THE GFS. DYNAMICS WILL NOT BE AS FAVORABLE
LATE IN THE WEEK BUT MID WEEK NEXT WEEK IS EXPECTED TO BE VERY
ACTIVE.

ALTHOUGH RAINFALL HAS NOT REACHED 1 INCH ANYWHERE AS OF 4 AM AST
HEAVY AMOUNTS ARE EXPECTED OVER THE ISLAND TODAY WITH WIDESPREAD
URBAN AND SMALL STREAM FLOODING AND LOCALIZED FLASH FLOODING
DURING THE DAY. A FLASH FLOOD WATCH HAS BEEN ISSUED.

&&

.AVIATION...UNSTABLE WEATHER CONDITIONS WILL CONTINUE TO PRODUCE
SHRA/TSRA OVER THE REGION DURING THE FORECAST PERIOD. SHRA/TSRA
EXPECTED AT TJSJ/TJPS/TJSJ/TJMZ WITH MOUNTAIN OBSCURATIONS BETWEEN
30/08-18Z. SHRA/TSRA ARE EXPECTED TO CONTINUE DURING MOST OF THE
DAY...AS A RESULT MVFR OR POSSIBLE IFR CONDITIONS ARE EXPECTED AT
PR/USVI TERMINALS. WINDS WILL CONTINUE FROM THE SE AT 10 TO 15 KT
AND HIGHER AND VARIABLE IN/NEAR SHRA/TSRA.


&&

.MARINE...WITH ONLY WEAK LOWS IN THE ATLANTIC...SWELLS FROM THE
NORTH AND NORTHEAST HAVE BEEN SMALL. WINDS WILL INCREASE LATER
THIS WEEKEND BUT FOR NOW SEAS ARE MOSTLY BELOW 6 FEET. SMALL CRAFT
NEED TO EXERCISE CAUTION IN THE OUTER ATLANTIC WATERS. SEAS SHOULD
SUBSIDE THROUGH 02 MAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 75 88 75 / 80 30 40 40
STT 87 76 88 76 / 60 40 30 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
214 PM AST SAT APR 30 2016

.SYNOPSIS...AMPLIYING UPPER LEVEL TROUGH JUST WEST OF HISPANOLA IS
ENHANCING THE INSTABILITY AND MOISTURE TRANSPORT OVER PUERTO RICO
AND THE U.S. VIRGIN ISLANDS. ADDITIONAL MID TO UPPER SHORT-WAVE
TROUGHS WILL CONTINUE TO STREAM OVER THE LOCAL REGION THROUGH
NEXT WEEK. AMPLE AREA OF MOISTURE WILL REMAIN OVER THE NORTHEAST
CARIBBEAN REGION OVER THE NEXT SEVERAL DAYS. AS A RESULT...HIGHLY
UNSTABLE AND MOIST ATMOSPHERE REMAINS OVER THE FORECAST AREA...
FAVORING THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS EVERYDAY.
UNSETTLED PATTERN WILL LIKELY PREVAIL UNTIL AT LEAST EARLY NEXT
WEEK.

&&

.DISCUSSION...VERY UNSTABLE AND MOIST AIR MASS OVER THE FORECAST
AREA HAVE RESULTED IN THE DEVELOPMENT SHOWERS AND THUNDERSTORMS
WITH HEAVY RAINFALL ACROSS MOST OF THE FORECAST AREA. INTENSE
THUNDERSTORMS MOVED FROM WEST TO EAST SINCE EARLY THIS MORNING
AFFECTING THE WEST...SOUTH AND EAST PORTIONS OF PUERTO RICO
THROUGH LATE THIS MORNING. AT THIS TIME...MOST OF THUNDERSTORMS
HAVE MOVED OVER CULEBRA...VIEQUES AND THE U.S. VIRGIN ISLANDS.
TORRENTIAL RAINS...FREQUENT LIGHTNING AND GUSTY WINDS UP TO 35
KNOTS HAVE BEEN OBSERVED WITH THE HEAVIEST STORMS.

VERY MOIST SOUTHEASTERLY FLOW ACROSS THE EASTERN CARIBBEAN WILL
CONTINUE TO PROMOTE MOISTURE CONVERGENCE ACROSS PUERTO RICO AND
THE US VIRGIN ISLANDS EARLY NEXT WEEK. THIS COMBINES WITH INFLOW
OF MID LEVEL ENERGY AND FAVORABLE JET DYNAMICS WILL SUSTAIN
UNSETTLED CONDITIONS OVER THE NEXT SEVERAL DAYS. SOILS ARE
RELATIVELY SATURATED ACROSS MOST OF THE ISLANDS AND ADDITIONAL
HEAVY RAINFALL WILL INCREASE THE FLOODING THREAT ACROSS PR AND THE
USVI. FOR THIS REASON...A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
AT LEAST 8 PM AST TONIGHT.

PATTERN WILL REMAIN HIGHLY FAVORABLE AND CONDUCIVE TO ORGANIZED
DEEP CONVECTION OVER THE NEXT SEVERAL DAYS. HIGH MOISTURE CONTENT
AND ADDITIONAL PERTURBATIONS AT MID-UPPER LEVELS WILL KEEP THE
CHANCES OF SHOWERS AND THUNDERSTORMS HIGH THROUGH THE FORECAST
PERIOD.

&&

.AVIATION...BRK IN CLD COVER OVR WRN PR TJBQ...TJMZ...TJPS.
HOWEVER...OVR ERN HALF OF PR AND EASTWARD TOWARDS THE NRN LEEWARDS
MULTIPLE CLD LYRS...SCT-BKN LYRS FL025...050...OVC BTW FL090-120.
ISOLD-SCT TSRA EN ROUTE BTW PR AND NRN LEEWARDS WITH LINE OF STRONG
SHRA/TSRA NOW CROSSING VIRGIN ISLANDS AND MOV W WITH MVFR/IFR CONDS
ATTM. MAX TOPS 450-500. MTN TOP OBSCR OVER ERN PR IN SHRA/LOW CIG
TIL 30/23Z. TEMPO MVFR/PSBL IFR CIG AND SHRA/TSRA EN ROUTE BTW
ISLANDS DURG PRD. PREVAILING VFR AT MOST LOCAL TERMINALS EXCEPT FOR
TEMPO IFR AT TISX...TIST WITH BRIEF MVFR IN SHRA/ISOLD TSRA
ELSEWHERE TIL 30/23Z.

&&

.MARINE...WINDS OF 5 TO 15 KNOTS AND SEAS OF 3 TO 5 FEET
RESPECTIVELY. MAIN HAZARD FOR MARINERS TODAY IS THE STRONG
THUNDERSTORMS OVER THE REGIONAL WATERS...ESPECIALLY NEAR
USVI...CULEBRA AND VIEQUES. SUDDEN WATERSPOUT WILL ALSO BE
POSSIBLE MAINLY BETWEEN EASTERN PUERTO RICO AND THE VIRGIN
ISLANDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 88 75 87 / 30 40 40 30
STT 76 88 76 85 / 40 30 50 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
521 AM AST SUN MAY 1 2016

.SYNOPSIS...A TROUGH WITH A WEAK CUT-OFF LOW WILL PASS THROUGH
THE AREA TODAY. A SECONDS WEAKER TROUGH WILL PASS THROUGH ON
TUESDAY TO PROLONG THE TIME THE TROUGH STAYS IN PLACE. BY THURSDAY
A RIDGE WILL BEGIN TO BUILD OVER THE AREA...MOVING OVER THE
LEEWARD ISLANDS BY LATE IN THE WEEK.

AT MID LEVELS...CONSIDERABLE DRYING WILL TAKE PLACE TODAY AND ONLY
MODEST MOISTURE WILL PERSIST THROUGH THE END OF THE WEEK. WEAK
TROUGHINESS WILL PERSIST OVER THE AREA THROUGH MID WEEK...THEN
HIGH PRESSURE WILL BUILD INTO THE CENTRAL ATLANTIC AND OVER THE
CARIBBEAN SEA.

AT LOWER LEVELS...HIGH PRESSURE ENTERING THE WESTERN ATLANTIC AND
BUILDING INTO THE CENTRAL ATLANTIC WILL MAINTAIN SOUTHEAST TRADE
WIND FLOW THROUGH THE REST OF THE WEEK. ABUNDANT MOISTURE WILL
INCREASE OVER THE AREA AFTER MONDAY KEEPING SHOWERS AND
THUNDERSTORMS IN THE FORECAST.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS HAD CLEARED OFF ALL BUT
THE SOUTHEAST PORTION OF THE FORECAST AREA BY LATE EVENING. BUT
THE LINE OF SHOWERS RETURNED AND NOW STRETCHES ACROSS THE
CARIBBEAN WATERS WITH SCATTERED SHOWERS. SHOWERS WENT OVER SAINT
CROIX AROUND 4 AM AST BUT THE HEAVIEST SHOWERS WENT AROUND THE
RAIN GAGE AT THE AIRPORT IN FREDERIKSTED. SHOWERS ARE WEAKENING AS
THEY APPROACH SAINT JOHN...SAINT THOMAS AND PUERTO RICO...BUT A
FEW ARE EXPECTED TO ARRIVE BY 8 AM AST. WITH SKIES CLEARING
HEATING SHOULD MAKE THINGS UNSTABLE AGAIN AND SHOWERS AND
THUNDERSTORMS WILL DEVELOP OVER PUERTO RICO. MODELS BARELY SHOW
THE AREA WHERE SHOWERS ARE FIRING OFF NOW...BUT RATHER SHOW A
WIDE AREA OF MOISTURE WITH LITTLE FORM...MAKING THE FORECAST
PARTICULARLY DIFFICULT TODAY. HOWEVER THE GFS BRINGS SOME
DIVERGENCE AT UPPER LEVELS ACROSS THE CENTER OF PUERTO RICO TODAY
FROM THE SOUTHWEST WHICH SHOULD HELP CONVECTION. OTHERWISE EXPECT
THE CONVECTION TO REMAIN MAINLY SOUTH AND EAST OF PUERTO RICO AND
POSSIBLY OVER THE U.S. VIRGIN ISLANDS. WINDS CONTINUE FROM THE
SOUTHEAST AND EXPECT WARMER TEMPERATURES TODAY. MOISTURE REACHES A
MINIMUM OVERNIGHT TONIGHT...BUT STILL AROUND 1.5 INCHES OF
PRECIPITABLE WATER. THEN OVER THE WEEK IT GRADUALLY RISES TO TWO
INCHES AGAIN. THE MODEL ALSO HAS 1000-850 MB THICKNESSES RISING
OVER THE AREA WITH THE WARMEST PERIOD FRIDAY THROUGH SUNDAY.
BECAUSE MOISTURE RISES THROUGH THE WEEK...THE FORECAST CAPE AND
LIFTED INDEX ALSO SHOW MORE INSTABILITY AS THE WEEK CONTINUES. THE
ONLY AMELIORATING FACTOR IS THAT MID LEVEL MOISTURE REMAINS MODEST
THROUGHOUT THE PERIOD...SO THE FLOODING POTENTIAL SHOULD REMAIN
LOCALIZED TO URBAN AND SMALL STREAM FLOODING IN THE INTERIOR AND
NORTHWEST PORTIONS OF THE ISLAND FOR THE ENTIRE WEEK. ALTHOUGH THE
SOUTH COAST WILL BE WARM...OF COURSE...THE NORTH COAST WILL ALSO
SEE TEMPERATURES RISE BETWEEN NOW AND THURSDAY... AND SAN JUAN
SHOULD BEGIN TO SEE A FEW LOWER 90S BY THE END OF THE WEEK.

&&

.AVIATION...-SHRA CAN BE EXPECTED FROM TIME TO TIME ACROSS MUCH OF
THE PR/USVI TERMINALS. ALSO...BKN/OVC HIGH CIRRUS WILL CONTINUE
ACROSS THE AREA. -TSRA/SHRA CAN STILL AFFECT THE LEEWARD
TERMINALS FROM TIME TO TIME...AND ALSO CAN MOVE ACROSS OR NEAR
THE USVI/SOUTHERN AND EASTERN PR TERMINALS THIS MORNING. DURING
THE AFTERNOON MTN TOP OBSCURATIONS OVER ERN...INTERIOR AND
NORTHWESTERN PR IN SHRA/LOW CIG ARE EXPECTED BETWEEN 01/15-23Z.
SFC WINDS FROM THE SOUTH AT 5 TO 10 KT WILL INCREASE TO 10 TO 15
KT AND LOCALLY HIGHER IN/NEAR TSRA/SHRA.


&&

.MARINE...SEAS ARE GRADUALLY MELLOWING OVER THE AREA...BUT WILL
INCREASE SOMEWHAT BETWEEN 5 AND 7 MAY. SMALL CRAFT ADVISORIES ARE
NOT EXPECTED DURING THE NEXT 7 DAYS AND SWELL FROM THE ATLANTIC
WILL BE MINIMAL.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 88 76 / 30 40 30 40
STT 83 78 87 76 / 50 50 50 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
206 PM AST SUN MAY 1 2016

.SYNOPSIS...UPPER LEVEL TROUGH LOCATED OVER PUERTO RICO
HAS BEEN ENHANCING THE INSTABILITY AND MOISTURE TRANSPORT
OVER PUERTO RICO AND THE U.S. VIRGIN ISLANDS DURING THE
WEEKEND. THE TROUGH ALOFT WILL WEAKEN THROUGH MIDWEEK.
ALTHOUGH...A RELATIVELY UNSTABLE PATTERN WILL PERSIST
MOST OF THE WEEK...DRIER AIR AT MID LEVELS WILL LIMIT
THE COVERAGE OF THE SHOWER AND THUNDERSTORM ACTIVITY.

&&

.DISCUSSION...HIGH CONVECTIVE INSTABILITY ASSOCIATED WITH
AN UPPER TROUGH OVER PUERTO RICO HAS RESULTED IN THE DEVELOPMENT
SHOWERS AND ISOLATED STRONG THUNDERSTORMS OVER MOST OF THE
FORECAST AREA. INTENSE RAINFALL WAS OBSERVED THIS MORNING
OVER PORTIONS OF THE WEST AND EAST THIRD OF PR. RAINFALL
ACCUMULATIONS OF 1-3 INCHES WERE ESTIMATED BY THE DOPPLER RADAR
ACROSS THE WEST...WESTERN INTERIOR AND NORTHEAST PR.

OPERATIONAL MODELS NOW SUGGEST THAT THE WEATHER CONDITIONS
WILL IMPROVE GRADUALLY THROUGH THURSDAY. AS UPPER TROUGH
WEAKENS AND DRIER AIR WILL FILTER IN AT MID LEVELS...THE
CONVECTIVE INSTABILITY WILL LIKELY DECREASE OVER THE LOCAL
AREA. ALTHOUGH...SHOWERS AND THUNDERSTORMS ARE STILL EXPECTED
OVER PORTIONS OF THE INTERIOR...NORTH AND NORTHWEST PR EACH
AFTERNOON...THE SHOWER AND THUNDERSTORM COVERAGE WILL DECREASE
THROUGH AT LEAST MIDWEEK. MAX TEMPERATURES WILL INCREASE SOMEWHAT
ACROSS THE LOCAL ISLANDS AS SOUTHEASTERLY FLOW AND LESS CLOUDINESS
ARE EXPECTED OVER THE NEXT COUPLE OF DAYS. MAX TEMPS WILL RANGE
FROM THE UPPER 80S TO LOW 90S...ESPECIALLY ALONG THE NORTH
COASTAL PLAINS.

&&

.AVIATION...PERIODS OF MVFR CONDS OR EVEN IFR CONDS WILL REMAIN
POSSIBLE AT THE USVI TERMINALS AS WELL AS JBQ/JMZ/JSJ IN SHRA/TSRA
DEVELOPMENT THROUGH ABOUT 01/22Z. ELSEWHERE...MAINLY VFR CONDS.
AFTER 01/22Z...VCSH IN AND AROUND THE LEEWARD...USVI AND JSJ
TERMINALS. SOUTHEAST WINDS AT 5 TO 10 KT...BECOMING LIGHT AND
VARIABLE OVERNIGHT.

&&

.MARINE...WINDS OF 5 TO 15 KNOTS AND SEAS OF 3 TO 5 FEET
RESPECTIVELY. MAIN HAZARD FOR MARINERS TODAY IS THE THUNDERSTORMS
OVER THE REGIONAL WATERS...ESPECIALLY NEAR USVI...AND NORTHEAST
PUERTO RICO. NO SMALL CRAFT ADVISORIES ARE ANTICIPATED OVER THE
NEXT 5-7 DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 88 76 88 / 30 30 40 30
STT 78 87 76 87 / 50 50 50 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
536 AM AST MON MAY 2 2016

.SYNOPSIS...AT UPPER LEVELS...A WEAK SHORT WAVE MOVED THROUGH THE
AREA OVERNIGHT AND ANOTHER IS EXPECTED TODAY AS WINDS RETURN TO
WEST SOUTHWEST UNTIL TUESDAY AFTERNOON. A BROAD RIDGE THEN PASSES
OVER ON WEDNESDAY NIGHT. THIS RIDGE MOVES INTO THE TROPICAL
ATLANTIC OVER THE WEEKEND. A STRONG LOW IS CURRENTLY PROGGED TO
MOVE INTO THE WESTERN ATLANTIC NEAR NEW JERSEY FRIDAY NIGHT MOVING
EAST AND ITS FRINGES SHOULD BEGIN AFFECTING THE LOCAL AREA
SATURDAY NIGHT OR SUNDAY.

AT MID LEVELS..WEAK TROUGHINESS EXTENDS INTO THE AREA FROM THE
NORTH THROUGH MID WEEK WHILE HIGH PRESSURE OCCUPIES MOST OF THE
CARIBBEAN. HIGH PRESSURE CONTINUES OVER THE CARIBBEAN THROUGH THE
WEEKEND AS THE LOW MOVES INTO THE WESTERN ATLANTIC NORTH OF THE
AREA SUNDAY AND MONDAY.

AT LOWER LEVELS...HIGH PRESSURE NORTH OF THE AREA AND IN THE
NORTHEAST ATLANTIC WILL CONSOLIDATE DURING THE MIDDLE OF THE WEEK
AND BUILD THROUGH FRIDAY OVER THE CENTRAL ATLANTIC. THIS WILL
MAINTAIN SOUTHEAST FLOW OVER THE LOCAL AREA WITH ABUNDANT MOISTURE
THROUGH AT LEAST MONDAY OF NEXT WEEK.

&&

.DISCUSSION...SHOWERS STAYED CLEAR OF THE FORECAST AREA FOR MUCH
OF THE NIGHT. BUT DURING THE PRE-DAWN HOURS...SHOWERS FROM THE
BAND OF MOISTURE TO OUR SOUTHEAST BEGAN MOVING INTO THE FORECAST
AREA EAST OF SAINT CROIX AND SOUTH OF VIEQUES AND SAINT CROIX. AT
5 AM AST SHOWERS WERE MOVING BETWEEN SAINT JOHN AND SAINT CROIX.
MODELS AGREE THAT SHOWERS WILL APPROACH THE AREA FROM THE
SOUTHEAST AGAIN TODAY...BUT THE GFS WAS MUCH TOO WET OVERNIGHT
PUTTING 60 TO 100 PERCENT POPS IN THE 02/06Z FORECAST IN VARIOUS
PLACES...MAINLY OVER WATER. SKIES ARE MOSTLY CLEAR OVER PUERTO
RICO AND THE U.S. VIRGIN ISLANDS AND THE EARLY PART OF THE MORNING
IS EXPECTED TO BE MOSTLY SUNNY WITH A RAPID WARM-UP. THEN CLOUDS
WILL FORM WITH SHOWERS OVER THE INTERIOR OF PUERTO RICO.
THUNDERSTORMS COULD BEGIN A EARLY AS 11 AM AST... BUT MOST WILL
WAIT TILL AFTERNOON.

TODAY IS A LITTLE DIFFERENT THAN YESTERDAY. THE BAND OF MOISTURE
IS A LITTLE FARTHER EAST AND WIND FLOW ALSO APPEARS TO BE A LITTLE
MORE EASTERLY. HOWEVER IN THE LOWEST 10 KFT THE GFS SHOWS THE
WIND VEERING FROM THE NORTHEAST AT 02/00Z TO EAST SOUTHEAST AT
02/18Z AND THIS SHOULD ALLOW SHOWERS AND THUNDERSTORMS TO VISIT
THE NORTHERN COASTAL PLAINS OF PUERTO RICO AS WELL AS THE
NORTHWEST CORNER OF THE ISLAND WITH THE POSSIBILITY OF A STREAMER
CROSSING SOUTHERN CAROLINA AND THE SAN JUAN BAY WITH HEAVY RAIN
DURING THE AFTERNOON. A SIMILAR PATTERN IS EXPECTED FOR TUESDAY
AND WEDNESDAY. THEN THURSDAY WINDS TURN MORE SOUTHERLY AND HEAVY
RAIN SHOWERS WILL FAVOR MORE OF THE NORTH COAST OF PUERTO RICO.
URBAN AND SMALL STREAM FLOODING SHOULD BE EXPECTED THIS WEEK
ACROSS A NUMBER OF AREAS MAINLY NORTH OF THE CORDILLERA CENTRAL.
MOS TENDS TO WARM UP CONSIDERABLY BEGINNING TOMORROW AND
STEEPENING THROUGH FRIDAY...BUT CLOUDS COULD KEEP IT FROM REACHING
THE LAST FEW DEGREES. NEVERTHELESS EXPECT SOME LOWER 90S BY FRIDAY
AS MENTIONED YESTERDAY.

MID LEVELS CONTINUE TO HAVE MODEST MOISTURE UNTIL DRIER AIR MOVES
IN SOMETIME NEXT WEEK. ALTHOUGH MODELS BRING IN A BULLS EYE OVER
STRONG DIVERGENCE IN THE THE UPPER LEVELS ON MOTHERS DAY THAT
WOULD APPEAR TO FAVOR STRONGER CONVECTION...IT IS STILL TOO FAR
OUT TO PLACE ANY CONFIDENCE IN HEAVY RAIN FOR THE WEEKEND.
NEVERTHELESS THE SITUATION BEARS MONITORING.

&&

.AVIATION...PASSING SHRA AND VCTS CAN BE EXPECTED MAINLY ACROSS
TIST/TISX/TJPS/TNCM/TKPK DURING THE MORNING HOURS. MOUNTAIN
OBSCURATIONS ACROSS THE INTERIOR AND WESTERN PR WITH TSRA/SHRA
AFT 02/16Z. AS A RESULT...EXPECT BKN CEILING AT FL025-FL060 AT
TJBQ/TJMZ/TJPS AND POSSIBLY AT TJSJ. THE SURFACE WINDS WILL
CONTINUE FROM THE SOUTH TO EAST-SOUTHEAST AT 10 TO 15 KNOTS WITH
SEA BREEZE VARIATIONS AFT 02/13Z.

&&

.MARINE...SEAS WILL PEAK AT AROUND 4.5 FEET ON TUESDAY NIGHT...BUT
IT IS MOSTLY EASTERLY WIND WAVES WITH LITTLE NORTHERLY SWELL. SEAS
THEN SUBSIDE UNTIL THURSDAY. NO SMALL CRAFT ADVISORIES ARE
EXPECTED THROUGH THE WEEKEND IN ANY LOCAL WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 75 87 75 / 60 30 30 20
STT 85 75 86 77 / 50 30 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
204 PM AST MON MAY 2 2016

.SYNOPSIS...MID TO UPPER LEVEL TROUGH WILL CONTINUE TO SLOWLY
LIFT EASTWARD ACROSS LOCAL REGION THROUGH TUESDAY.IN THE LOW
LEVELS...SURFACE HIGH PRESSURE CENTERED ACROSS THE NORTH CENTRAL
ATLANTIC WILL MAINTAIN A MOIST SOUTHEAST WIND FLOW ACROSS THE
REGION THROUGH AT LEAST WEDNESDAY. WINDS ARE TO THEN BECOME MORE
SOUTHERLY DURING THE LATTER PART OF THE WORK WEEK AS THE ATLANTIC
HIGH BUILDS AND SINKS SOUTHWARD ACROSS THE CENTRAL ATLANTIC. THE
OVERALL WEATHER PATTERN WILL MAINTAIN AN MOIST AND UNSTABLE
ENVIRONMENT THROUGH THE MIDDLE OF THE WEEK.

&&

.DISCUSSION...FAVORABLE AND UNSTABLE CONDITIONS WILL CONTINUE
TODAY THROUGH EARLY WEDNESDAY AS PREVIOUSLY MENTIONED. FOR TODAY
EXPECT MOST ACTIVE AREAS TO BE FOCUSED ACROSS THE NORTHERN HALF
AND AND NORTHWESTERN SECTIONS OF PUERTO RICO RICO AS WELL AS OVER
ISOLATED AREAS IN THE U.S. VIRGIN ISLANDS DURING THE REST OF THE
AFTERNOON AND INTO THE EVENING HOURS. DUE TO SATURATED SOILS AND
UNSTABLE CONDITIONS...MINOR FLOODING OF URBAN AREAS AS WELL AS
QUICK RISES IN WATER LEVELS OF SOME RIVERS...SMALL STREAMS...AND
GUTS WILL REMAIN POSSIBLE FOR THE REST OF THE DAY OVER MUCH OF OF
THE ISLANDS. FOR THE NEXT FEW DAYS...THE MOIST SOUTHEAST FLOW AND
UNSTABLE CONDITIONS ALOFT WILL BE THE DRIVING FORCE OF ENHANCED
CONVECTIVE DEVELOPMENT ACROSS THE ISLANDS AND COASTAL WATERS WITH
INCREASE POTENTIAL FOR MINOR FLOODING SITUATIONS.

BY WEDNESDAY...THE UPPER TROUGH IS TO FILL AND LIFT NORTHEAST AND
THE HIGH PRESSURE RIDGE IS FORECAST TO BUILD ALOFT ACROSS THE REGION
THROUGH THURSDAY.THIS CHANGE IN THE WEATHER PATTERN WILL LEAD TO A
DECREASE IN WIDESPREAD CONVECTION ACROSS THE ISLANDS. HOWEVER SUFFICIENT
LOW LEVEL MOISTURE CONVERGENCE COMBINED WITH LOCAL TERRAIN EFFECTS AND
DAYTIME HEATING WILL LEAD TO PERIODS OF SHOWER AND ISOLATED THUNDERSTORM
DEVELOPMENT MAINLY OVER PORTIONS THE CENTRAL AND NORTHWESTERN SECTIONS
OF PUERTO RICO. ISOLATED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ELSEWHERE.

BASED ON THE LATEST GFS MODEL GUIDANCE...THIS SHIFT IN THE WEATHER PATTERN
WILL BE SHORT LIVED AS A DEEP POLAR TROUGH WILL BECOME AMPLIFIED ACROSS
THE WESTERN ATLANTIC AND QUICKLY ERODE THE RIDGE BY LATE THURSDAY AND
IN TO THE UPCOMING WEEKEND. AS A RESULT A RETURN TO A MOIST AND UNSTABLE
WEATHER PATTERN IS AGAIN EXPECTED WITH GOOD POTENTIAL FOR PERIODS OF
STRONG CONVECTIVE DEVELOPMENT ACROSS THE COASTAL WATERS AND PORTIONS
OF THE INTERIOR AND NORTHERNHALF OF PUERTO RICO RICO. ALL IN ALL...THE
POTENTIAL FOR URBAN AND SMALL STREAM FLOODING WILL CONTINUE MOST OF
THE WEEK WITH THE STRONGEST ACTIVITY FOCUSED THE EAST AND SOUTHEAST
SECTIONS OF PUERTO RICO AND ON THE WINDWARD SIDE OF THE VIRGIN ISLANDS
DURING THE LATE EVENING AND EARLY MORNING HOURS. THE ACTIVITY IS TO
THEN SHIFT TO THE NORTH AND NORTHWESTERN SECTIONS OF PUERTO RICO DURING
THE AFTERNOON HOURS.

&&

.AVIATION...MOSTLY VFR COND WITH VCSH CAN BE EXPECTED ACROSS THE TAF
SITES. MOUNTAIN OBSC PSBL ACROSS THE INTERIOR AND WESTERN PR
UNTIL AROUND 02/22Z. THE SURFACE WINDS WILL CONTINUE FROM THE
SOUTH TO EAST-SOUTHEAST AT 10 TO 15 KNOTS WITH SEA BREEZE
VARIATIONS.

&&

.MARINE...OVERALL FAIRLY TRANQUIL SEAS EXPECTED OVERNIGHT .
HOWEVER...SHOWERS AND THUNDERSTORM DEVELOPMENT WILL CONTINUE
ACROSS THE LOCAL WATERS THROUGH TUESDAY. THIS WILL CONTINUE TO
CREATE HAZARDOUS MARINE CONDITIONS DUE TO LOCALLY HIGHER WAVES AND
WIND GUSTS NEAR THE STORMS. OTHERWISE...SEAS UP TO 5 FEET AND
WINDS UP TO 15 KNOTS ARE EXPECTED.

&&

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
558 AM AST TUE MAY 3 2016

.SYNOPSIS...A MID TO UPPER LEVEL TROUGH WILL CONTINUE TO SLOWLY
LIFT EASTWARD ACROSS LOCAL REGION TODAY. AS THE TROUGH MOVES
EASTWARD...IT IS EXPECTED TO LEAVE THE AREA BY WEDNESDAY AND
THURSDAY. BY FRIDAY...ANOTHER UPPER LEVEL TROUGH IS EXPECTED TO
REACH THE AREA. IN THE LOW LEVELS...AN INDUCED SURFACE TROUGH WILL
MOVES ACROSS THE REGION TODAY. A SURFACE HIGH PRESSURE CENTERED
ACROSS THE NORTH CENTRAL ATLANTIC WILL MAINTAIN A MOIST SOUTHEAST
WIND FLOW ACROSS THE REGION THROUGH AT LEAST WEDNESDAY.

&&

.DISCUSSION...THUNDERSTORMS MOVED ACROSS THE SURROUNDING WATERS
OF ST CROIX AND ST THOMAS OVERNIGHT. THE DOPPLER RADAR DETECTED
SHOWERS WITH PERIODS OF MODERATE TO HEAVY RAIN AFFECTING ST
CROIX...PRODUCING LOCALIZED URBAN AND SMALL STREAM FLOODING. FOR
TODAY...THE LINGERING MOISTURE WILL CONTINUE TO PRODUCE SOME
PASSING SHOWERS MAINLY ACROSS THE SURROUNDING WATERS...AND THE
WINDWARD SECTIONS OF PR AND USVI. DURING THE AFTERNOON...UNDER
THE SOUTHERLY WIND FLOW...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED MAINLY DOWNWIND FROM EL YUNQUE...AND THE U.S. VIRGIN
ISLANDS. IN ADDITIONS...AFTERNOON CONVECTION IS EXPECTED ALONG THE
CORDILLERA CENTRAL AND NORTHWESTERN QUADRANT OF PUERTO RICO. DUE
TO THE PREVIOUS RAIN EVENTS...THE SOILS ARE SATURATED AND ANY
HEAVY RAINFALL EVENT WILL PRODUCE LOCALIZED FLOODING...AND
MUDSLIDES ACROSS STEEP TERRAIN.

THE LATEST MODEL GUIDANCE SHOWED THE MID TO UPPER LEVEL TROUGH
LEAVING THE AREA AS AN UPPER LEVEL RIDGE BUILDS OVER THE ISLANDS
BY WEDNESDAY AND THURSDAY. AS A RESULT...THE INSTABILITY SHOULD
DIMINISH BY THESE DAYS...CHANGING THE WEATHER PATTERN AND
DECREASING THE POTENTIAL FOR WIDESPREAD SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. HOWEVER...THE AVAILABLE TROPICAL SURFACE
MOISTURE COMBINED WITH LOCAL TERRAIN EFFECTS AND DAYTIME HEATING
WILL LEAD TO PERIODS OF SHOWER AND ISOLATED THUNDERSTORM EACH DAY
ACROSS SECTIONS OF PUERTO RICO AND DOWNWIND FROM THE US VIRGIN
ISLANDS.

GFS SUGGEST THE ARRIVAL OF A POLAR TROUGH BY FRIDAY INTO THE
UPCOMING WEEKEND. ONCE AGAIN GFS MODEL GUIDANCE...AMPLIFIED THIS
POLAR TROUGH ACROSS THE WESTERN ATLANTIC...AS A RESULT AN UNSTABLE
WEATHER PATTERN IS EXPECTED TO PREVAIL BY FRIDAY INTO THE MOTHERS
DAY WEEKEND. THEREFORE...DEEP CONVECTION IS EXPECTED ONCE AGAIN
ACROSS THE COASTAL WATERS AND PORTIONS OF THE INTERIOR AND
NORTHERN HALF OF PUERTO RICO.

&&

.AVIATION....BRIEF PERIODS OF MVFR CONDITIONS IN SHRA TO PREVAIL
ACROSS TNCM/TKPK. AFT 03/15Z SHRA/TSRA DEVELOP ACROSS NW AND N
CENTRAL PR IN MOIST SE FLOW PRODUCING PERIODS OF MVFR AND BRIEF
IFR CONDS. WIND FLOW ALSO APPEARS TO LINE UP BETWEEN TISX...TVQS
AND EL YUNQUE TO PLACE TJSJ IN LINE TO RECEIVE +TSRA AND BRIEF
MVFR CIGS AND IFR VSBYS BTWN 03/15-18Z. OUTLOOK IS FOR AREAS OF
SHRA/TSRA TO CONTINUE OVER LOCAL WATERS BYD 04/06Z. SFC WINDS ESE
5 TO 15 KT WITH HIR GUSTS NR TSRA. LAND AND SEABREEZE INFLUENCES
IN LOCAL FLOW. MODELS UNDERESTIMATING WINDS BTWN SFC AND FL110
EXPECT ESE 15 TO 25 KT.

&&

.MARINE...TRANQUIL MARINE WEATHER CONDITIONS EXPECTED TODAY. THE
LOCAL BUOY NETWORK CONTINUES TO INDICATE SEAS BETWEEN 3 TO 4 FEET
AND EAST-SOUTHEAST WINDS AT 10-15 KNOTS. HOWEVER...WINDS ARE
EXPECTED TO INCREASE AT 15 TO 20 KNOTS DURING THE AFTERNOON
MAINLY ACROSS THE COASTAL WATERS OF NORTHERN PUERTO RICO.
ALTHOUGH...RELATIVE TRANQUIL CONDITIONS ARE EXPECTED...SHOWERS
AND THUNDERSTORM DEVELOPMENT WILL CONTINUE ACROSS THE LOCAL WATERS
TODAY. OTHERWISE EXPECT SEAS BELOW 5 FEET AND WINDS UP TO 18
KNOTS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 87 76 / 60 30 30 20
STT 84 75 85 78 / 40 20 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
203 PM AST TUE MAY 3 2016

.SYNOPSIS...UPPER LEVEL TROUGH LOCATED OVER PUERTO RICO IS
ENHANCING SOMEWHAT THE INSTABILITY OVER PUERTO RICO AND
THE U.S. VIRGIN ISLANDS TODAY. THE TROUGH ALOFT WILL WEAKEN
AS LIFTS NORTHEAST ON WEDNESDAY. MID-UPPER LEVEL RIDGE WILL
MOVE OVER THE REGION BETWEEN WEDNESDAY AND THURSDAY...LIMITING
THE COVERAGE AND INTENSITY OF THE SHOWERS. SURFACE HIGH PRESSURE
OVER THE CENTRAL ATLANTIC WILL MAINTAIN A GENERALLY MOIST
SOUTHEASTERLY FLOW ACROSS THE LOCAL ISLANDS THROUGH THE WEEKEND.

&&

.DISCUSSION...CONVECTIVE INSTABILITY ASSOCIATED WITH AN UPPER
TROUGH OVER PUERTO RICO HAS RESULTED IN THE DEVELOPMENT SHOWERS
AND ISOLATED THUNDERSTORMS OVER PORTIONS OF THE NORTH CENTRAL AND
NORTHWEST PUERTO RICO THIS AFTERNOON. ADDITIONAL SHOWERS WILL
DEVELOP ACROSS THESE AREAS THROUGH AT LEAST LATE THIS AFTERNOON.

OPERATIONAL MODELS NOW SUGGEST THAT THE WEATHER CONDITIONS WILL
IMPROVE GRADUALLY THROUGH THURSDAY. AS UPPER TROUGH WEAKENS AND
SOME DRY AIR WILL FILTER IN AT MID LEVELS. THE CONVECTIVE
INSTABILITY WILL LIKELY DECREASE OVER THE LOCAL AREA. ALTHOUGH...
SHOWERS AND THUNDERSTORMS ARE STILL EXPECTED OVER THE NORTHWEST
QUADRANT OF PR EACH AFTERNOON...THE SHOWER AND THUNDERSTORM
COVERAGE WILL DECREASE OVER THE NEXT FEW DAYS. MAX TEMPERATURES
WILL INCREASE SOMEWHAT ACROSS THE LOCAL ISLANDS AS SOUTHEASTERLY
FLOW AND LESS CLOUDINESS ARE EXPECTED OVER THE NEXT COUPLE OF
DAYS. MAX TEMPS WILL RANGE FROM THE UPPER 80S TO LOW 90S...
ESPECIALLY ALONG THE NORTH COASTAL PLAINS.

FROM FRIDAY INTO THE WEEKEND...A POLAR TROUGH WILL DOMINATE
THE WESTERN ATLANTIC. AT THIS TIME...LOOKS LIKE THE ORGANIZED
CONVECTION WILL REMAIN WEST AND NORTH OF THE LOCAL AREA.

&&

.AVIATION...SHRA AND VCTS IN/AROUND TJBQ/TJMZ AND MOUNTAIN
OBSCURATION ACROSS INTERIOR AND NW SECTION OF PR AFTER 03/18Z.
SFC WINDS ESE 5 TO 15 KT WITH HIGHER GUSTS NEAR TSRA.

&&

.MARINE...WINDS OF 5 TO 15 KNOTS AND SEAS OF 3 TO 5 FEET
RESPECTIVELY. NO SMALL CRAFT ADVISORIES ARE ANTICIPATED OVER THE
NEXT 5-7 DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 87 76 90 / 30 30 20 50
STT 75 85 78 85 / 20 20 20 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
608 AM AST WED MAY 4 2016

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION
BETWEEN TODAY AND THURSDAY...AS THE MID TO UPPER LEVEL TROUGH
MOVES EASTWARD. BY THE UPCOMING WEEKEND...A POLAR TROUGH IS
EXPECTED TO REACH THE AREA. AT THE SURFACE...A DISTURBANCE WILL
MOVES ACROSS THE REGION TODAY. A SURFACE HIGH PRESSURE OVER THE
CENTRAL ATLANTIC WILL MAINTAIN A GENERALLY MOIST SOUTHEASTERLY
FLOW ACROSS THE LOCAL ISLANDS THROUGH THE WEEKEND.

&&

.DISCUSSION...PARTLY TO MOSTLY CLOUDY SKIES WERE OBSERVED ACROSS
THE ISLANDS. THE DOPPLER RADAR DETECTED A BAND OF SHOWERS ACROSS
THE ATLANTIC OFFSHORE AND CARIBBEAN WATERS OVERNIGHT. SOME SHOWERS
MOVED ACROSS THE SOUTHERN AND EASTERN SECTIONS OF PUERTO RICO.
ALSO...THUNDERSTORM ACTIVITY WAS DETECTED ACROSS THE CARIBBEAN
WATERS.

UNDER WEAKENING TROUGH...THE SOUTHERLY FLOW AND THE AVAILABLE LOW
LEVEL MOISTURE...CONTINUE TO EXPECT SHOWER ACTIVITY ACROSS THE
LOCAL WATERS...AND THE WINDWARD SECTIONS OF PUERTO RICO THIS
MORNING. ALSO...THE U.S. VIRGIN ISLANDS CAN EXPECT ONE OR TWO
SHOWERS DURING THE MORNING HOURS. FOR THE AFTERNOON HOURS...THE
AVAILABLE MOISTURE IS FORECAST TO COMBINE WITH THE DIURNAL AND
LOCAL EFFECTS TO AID IN THE DEVELOPMENT OF SHOWERS AND ISOLATED
THUNDERSTORMS. MINOR URBAN AND SMALL STREAM FLOODING WILL ONCE
AGAIN BE POSSIBLE TODAY WITH THE HEAVIEST AND MOST PERSISTENT
SHOWERS.

AS THE UPPER LEVEL RIDGE BUILDS OVER THE REGION TODAY INTO
FRIDAY...SHOWER ACTIVITY IS EXPECTED TO DIMINISH SOMEHOW DURING
THAT PERIOD. HOWEVER...IT IS NOT STRONG ENOUGH TO SUPPRESS THE
SHOWER AND THUNDER ACTIVITY OVER AND NORTH OF THE CORDILLERA EACH
AFTERNOON. AN UPPER LEVEL TROUGH IS FORECAST TO RETURN TO THE
FORECAST AREA BY LATE FRIDAY INTO THE WEEKEND. BASED ON THE LATEST
MODEL GUIDANCE...MOIST AND UNSTABLE CONDITIONS ARE EXPECTED TO
RETURN DURING THE UPCOMING MOTHERS DAY WEEKEND.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES THROUGH
AT LEAST 04/16Z. PERIODS OF MVFR CONDITIONS WITH MOUNTAIN
OBSCURATIONS ARE EXPECTED OVER TJMZ AND TJBQ FROM 04/16-04/22Z. VCSH
ARE EXPECTED OVER TJSJ. LOW LEVEL WINDS WILL BE MAINLY SOUTHEAST AT
10 TO 15 KTS.

&&

.MARINE...TRANQUIL MARINE CONDITIONS EXPECTED DURING THE NEXT FEW
DAYS...WITH SEAS UP TO 5 FEET AND WINDS AROUND 15 KNOTS. SEAS AND
WINDS LOCALLY HIGHER IN THUNDERSTORMS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 76 90 77 / 30 20 40 20
STT 86 78 87 78 / 20 20 30 30

&&

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
158 PM AST WED MAY 4 2016

.SYNOPSIS...
MID TO UPPER TROUGH OVER THE NORTHEASTERN CARIBBEAN WILL CONTINUE
TO WEAKEN/FILL AND LIFT FARTHER EAST NORTHEAST OF THE FORECAST
AREA TODAY THROUGH EARLY THURSDAY. THIS WILL GIVE WAY TO A DEVELOPING
UPPER LEVEL RIDGE WHICH WILL PLACE THE REGION ON THE CONVERGENT/SUBSIDENT
SIDE OF THE UPPER TROUGH. LESS FAVORABLE CONDITIONS ALOFT FOR SIGNIFICANT
CONVECTIVE DEVELOPMENT CAN THEN BE EXPECTED ACROSS THE ISLANDS AND COASTAL
WATERS. HOWEVER...BY LATE THURSDAY AND THROUGH THE REST OF THE WEEK...THIS
RIDGE PATTERN IS TO ERODE IN RESPONSE TO A HIGH AMPLITUDE LONG WAVE
TROUGH DEEPENING ACROSS THE WEST AND SOUTHWEST ATLANTIC. THIS SYNOPTIC
PATTERN IS TO THEN HOLD IN PLACE THROUGH THE UPCOMING WEEKEND. LOW
LEVEL SUBTROPICAL RIDGE IS TO REMAIN ANCHORED ACROSS THE CENTRAL BUT
WILL BUILD AND SHIFT SLIGHTLY SOUTH AND EAST ACROSS THE ATLANTIC BY
FRIDAY AND INTO THE WEEKEND.

&&

.DISCUSSION...MODELS GUIDANCE CONTINUE TO SUGGEST THAT THE LONG
WAVE TROUGH WILL DEEPEN ACROSS THE WESTERN ATLANTIC AND SINK INTO
THE NORTHWEST CARIBBEAN THEN CONTINUE THROUGH THE WEEKEND. AS A
RESULT THE UPPER TROUGH IS FORECAST TO REMAIN JUST WEST OF THE
REGION FAVORING INCREASING INSTABILITY FOR FRIDAY AND INTO THE
WEEKEND. IN THE LOW LEVELS...THE DEEPENING POLAR TROUGH AND
ASSOCIATED COLD FRONT WILL MOVE ACROSS THE WESTERN ATLANTIC AND
SLOWLY LIFT EAST NORTHEAST RIDING THE PERIPHERY OF THE ATLANTIC
SUBTROPICAL RIDGE. THIS SURFACE HIGH WILL CONTINUE TO BUILD AND
REMAIN ANCHORED ACROSS THE CENTRAL AND EASTERN ATLANTIC THROUGH
THE WEEKEND. THIS PATTERN WILL SUPPORT INITIALLY A LOW LEVEL
SOUTHEAST WINDS THROUGH FRIDAY...THEN MODEL GUIDANCE SUGGEST LOW
LEVEL WINDS GRADUALLY VEERING AND BECOMING EVEN MORE SOUTHERLY
OVER THE WEEKEND.

BY THE WEEKEND THIS LOW LEVEL SOUTHERLY WIND FLOW WILL COMBINE
WITH INCREASING CAP INVERSION RESULTING IN WARMER SURFACE TEMPERATURES
ESPECIALLY ALONG THE NORTHERN HALF OF PUERTO RICO...WITH THE HOTTEST
DAY EXPECTED TO BE ON SATURDAY. WITH THAT SAID...FOR THE NEXT COUPLE
OF DAYS...EXPECT CONVECTIVE ACTIVITY TO BE LESSER ENHANCED AND SHOULD
BE FOCUSED OVER THE CENTRAL AND NORTHWEST SECTION OF PUERTO RICO.
THE PRESENT WIND FLOW WILL ALSO STEER SHOWERS OVER AND AROUND PARTS
OF THE SAN JUAN METRO AREA. INCREASING INSTABILITY ALOFT AND STRONG
TROPICAL MOISTURE CONVERGENCE BY FRIDAY AND INTO THE WEEKEND WILL
ALLOW BETTER CHANCE FOR ACTIVITY WEATHER CONDITIONS WITH MODELS CONTINUING
TO SUGGEST A FAIRLY WET PATTERN SUNDAY INTO MONDAY OF NEXT WEEK.

&&

.AVIATION...MVFR CONDS STILL PSBL AT TJMZ AND TJBQ IN PASSING TSRA
THRU 22Z. ALSO...SOME VCSH MAY AFFECT BRIEFLY TJSJ. VFR CONDS
EXPECTED ELSEWHERE. ESE WINDS OF 10-15 KT EXPECTED BELOW FL100.

&&

.MARINE...WINDS OF 5 TO 15 KNOTS WILL PREVAIL ACROSS THE REGIONAL
WATERS WITH SEAS OF 3 TO 5 FEET OVER THE NEXT SEVERAL DAYS. NO
SMALL CRAFT ADVISORIES ARE ANTICIPATED OVER THE NEXT 5-7 DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 90 77 91 / 20 40 20 40
STT 78 87 78 86 / 40 40 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
542 AM AST THU MAY 5 2016

.SYNOPSIS...MID TO UPPER TROUGH OVER THE NORTHEASTERN CARIBBEAN
WILL CONTINUE TO WEAKEN/FILL AND LIFT FARTHER EAST NORTHEAST OF
THE FORECAST AREA TODAY. THIS WILL GIVE WAY TO A DEVELOPING UPPER
LEVEL RIDGE WHICH WILL PLACE THE REGION ON THE CONVERGENT/SUBSIDENT
SIDE OF THE UPPER TROUGH. A POLAR TROUGH WILL DIG SOUTH WEST OF
THE AREA THE FIRST PART OF NEXT WEEK. HIGH MOISTURE CONTENT WILL
REMAIN ACROSS THE REGION.

&&

.DISCUSSION...SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS MOVED
ACROSS THE SOUTHEAST SECTION OF PUERTO RICO EARLY THIS MORNING.
RAINFALL ESTIMATED WERE BETWEEN HALF TO ONE INCH MAINLY OVER
ARROYO AND PATILLAS. LOCAL AREA REMAINED UNDER A MOIST SOUTH
SOUTHEAST WIND FLOW. PRECIPITABLE WATER WILL CONTINUE TO BE AROUND
2.0 INCHES THE REST OF THE WEEK. THIS HIGH MOISTURE CONTENT WILL
INDUCE SHOWER AND THUNDERSTORM ACTIVITY MAINLY EACH AFTERNOON
ACROSS THE NORTHERN HALF OF PUERTO RICO.

A SOUTHEAST EAST TO SOUTH SOUTHEAST WIND FLOW WILL CONTINUE TO
PREVAIL ACROSS THE LOCAL AREA THROUGH MONDAY. AS A RESULT...WARMER
THAN NORMAL TEMPERATURE WILL OCCUR MAINLY ALONG THE NORTHERN
SLOPES OF PUERTO RICO. FOR TUESDAY NEXT WEEK...A POLAR TROUGH WILL
MOVE CLOSER TO THE AREA...HELPING IN THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS ACROSS THE AREA.


&&

.AVIATION...MOSTLY VFR CONDITIONS WILL CONTINUE ACROSS THE TAF
SITES. VCSH EXPECTED ACROSS TJSJ/TJPS/TIST/TISX/TNCM/TKPK OVERNIGHT
AND EARLY MORNING HRS. PERIODS OF MVFR CONDITIONS AND POS VCTS WITH
MOUNTAIN OBSCURATIONS ARE EXPECTED OVER TJMZ AND TJBQ AFTER 05/16Z.
SFC WINDS WILL BE MAINLY SE AT AROUND 5-10 KTS...INCREASING UP TO
15 KTS AFTER 05/14Z WITH SEA BREEZE VARIATIONS.

&&

.MARINE...TRANQUIL MARINE CONDITIONS EXPECTED DURING THE NEXT FEW
DAYS...WITH SEAS UP TO 5 FEET AND WINDS AROUND 15 KNOTS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 91 78 / 40 20 40 10
STT 86 79 86 79 / 30 30 30 10

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
219 PM AST THU MAY 5 2016

.SYNOPSIS...BROAD UPPER TROUGH WILL AMPLIFY SLOWLY ACROSS THE
WESTERN ATLANTIC INTO THE CARIBBEAN DURING THE NEXT FEW DAYS. MID
TO UPPER RIDGE WILL BUILD QUICKLY OVER THE AREA THROUGH SATURDAY.
SURFACE HIGH PRESSURE WILL CONTINUE ACROSS THE CENTRAL ATLANTIC
WHILE SURFACE LOW AND ASSOCIATED FRONT OVER THE WESTERN ATLANTIC
CONTINUES TO MOVE FARTHER NORTH INDUCING A DEEP LAYER SOUTHERLY
WIND FLOW ACROSS THE FORECAST AREA.


&&

.DISCUSSION...LOCALLY INDUCED AFTERNOON SHOWERS FORMED OVER THE NW
QUADRANT OF THE ISLAND EARLY IN THE AFTERNOON. SO FAR...RAINFALL
ACCUMULATIONS ARE LESS THAN ONE INCH AS ESTIMATED BY THE DOPPLER
RADAR. A FEW SHOWERS WERE ALSO NOTED ACROSS EL YUNQUE AREA AND
SOME MOVING OVER THE CARIBBEAN WATERS THAT WILL EVENTUALLY REACH
THE SOUTHEASTERN SECTIONS OF PR DURING THE REST OF THE AFTERNOON
HOURS.

MID TO UPPER RIDGE OVER THE CARIBBEAN BASIN WILL PROMOTE SOMEWHAT
DRIER AIR AND UNFAVORABLE DYNAMICS ACROSS THE FORECAST AREA
THROUGH AT LEAST SATURDAY. HOWEVER...THE AVAILABLE LOW LEVEL MOISTURE
WILL BE ENOUGH TO CREATE TRADE WIND SHOWER ACTIVITY UNDER
SOUTHERLY WIND FLOW ACROSS THE USVI/SOUTHEASTERN SECTIONS OF PR
EACH NIGHT AND DURING THE EARLY MORNING HOURS...FOLLOWED BY
LOCALLY INDUCED AFTERNOON SHOWERS NORTH OF THE CORDILLERA.

FOR LATE SUNDAY INTO EARLY NEXT WEEK...THE DEEP LAYERED TROUGH AND
ASSOCIATED FRONTAL BOUNDARY WILL MOVE OVER FROM THE
WEST...INCREASING FAVORABLE UPPER LEVEL DYNAMICS AND LOW LEVEL
CONVERGENCE ACROSS THE MONA PASSAGE AND THE ATLANTIC WATERS. THIS
IN TURN WILL FAVOR ENHANCED AFTERNOON CONVECTION OVER THE MOUNTAIN
RANGED AND THE NORTHERN AREAS OF PR. AS WINDS CONTINUE FROM THE
SOUTH...SLIGHTLY ABOVE WARMER THAN NORMAL TEMPERATURES ARE
EXPECTED THROUGH AT LEAST SATURDAY AFTERNOON. AS UPPER TROUGH
APPROACHES ON SUNDAY...HIGH CIRRUS CLOUDS WILL MOVE OVER THE
ISLANDS AND THIS IN TURN CAN KEEP TEMPS AT NORMAL LEVELS...AND
ALSO OFFSET THE TIME OF THE DIURNALLY INDUCED AFTERNOON SHOWERS.


&&

.AVIATION...MOSTLY VFR CONDS WILL CONTINUE ACROSS THE TAF SITES
DURG PRD. SCT OCNL BKN CLD LYR FL025...050. AT LEAST UNTIL 05/23Z
VCSH/PSBL ISOLD MAY DEVELOP OVER THE INTERIOR SECTIONS OF PR AND
STEER NORTHWEST IN THE VCNTY OF/OR ACROSS TJBQ...TJSJ...TJMZ. SHRA
VCTY OF TISX...TIST...TNCM TIL 05/23Z. SFC WINDS WILL BE MAINLY SE
EXCEPT FOR SEA BREEZE VARIATIONS ALONG THE COASTAL AREAS...AROUND 5-
15 KTS TIL 05/23Z.


&&

.MARINE...SEAS SHOULD CONTINUE BELOW 5 FEET THROUGH THE WEEKEND.
WINDS WILL BE FROM THE SOUTHEAST GENERALLY BETWEEN 10-15
KNOTS...WITH OCCASIONAL HIGHER GUSTS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 91 78 91 / 20 40 10 50
STT 79 86 79 86 / 30 30 10 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
507 AM AST FRI MAY 6 2016

.SYNOPSIS...AN UPPER TROUGH AND A FRONTAL BOUNDARY ACROSS EASTERN CUBA...
HAITI AND THE BAHAMAS IS EXPECTED TO INCREASE THE INSTABILITY
ACROSS THE REGION SUNDAY AND MONDAY. THESE FEATURES WILL INCREASE
AGAIN THE CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHEAST CARIBBEAN. A SOUTH WIND FLOW WILL PREVAIL ACROSS THE
REGION THROUGH MONDAY. WINDS WILL SHIFT EASTERLY BY MONDAY.

&&

.DISCUSSION...SOME SHOWERS WERE OBSERVED OVER THE COASTAL
AREAS...WITH SOME AFFECTING THE SOUTH AND EAST SECTION OF PUERTO
RICO. ANOTHER LINE OF SHOWERS AFFECTED SAINT THOMAS AND SAINT JOHN
IN THE U.S. VIRGIN ISLANDS. LOCAL AREA REMAINED UNDER THE
INFLUENCES OF A WEAK HIGH PRESSURE AREA TO THE EAST AND AN UPPER
TROUGH AND FRONTAL BOUNDARY WEST OF THE AREA. THE COMBINATION OF
THESE FEATURES ARE PRODUCING A SOUTH WIND FLOW ACROSS THE REGION.
AS A RESULT...WARMER THAN NORMAL TEMPERATURES ARE EXPECTED MAINLY
ALONG THE NORTHERN HALF OF PUERTO RICO THIS AFTERNOON.

THIS SOUTHERLY WIND FLOW IS BRINGING WITH IT DEEP TROPICAL
MOISTURE WHICH WILL AID IN THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE LOCAL REGION EACH AFTERNOON. FOR THE
EARLY PART OF NEXT WEEK...THE AFORMENTIONED FRONTAL BOUNDARY IS
EXPECTED TO SLOWLY WEAKENS NORTH OF THE AREA. HOWEVER...MOISTURE
ASSOCIATED WITH IT IS EXPECTED TO MOVE ACROSS THE REGION MONDAY
AND TUESDAY...KEEPING HIGH CHANCES FOR SHOWERS AND THUNDERSTORMS
ACROSS THE REGION.


&&

.AVIATION...MOSTLY VFR COND EXPECTED AT ALL TAF SITES THROUGH
FORECAST PERIOD. VCSH ACROSS TJPS/TJSJ/TIST/TISX OVERNIGHT. PERIODS
OF MVFR COND WITH MTN OBSCURATIONS EXPECTED OVER TJMZ AND TJBQ BTW
06/16 AND 06/22Z. BASED ON 06/00Z SOUNDING...LOW LEVEL WINDS
CONTINUE SE AT AROUND 10 KTS OVERNIGHT...INCREASING TO 10-15 KTS
AFTER 06/14Z WITH SEA BREEZE VARIATIONS.

&&

.MARINE...SEAS UP TO 5 FEET AND WINDS UP TO 15 KNOTS ARE EXPECTED
OVER THE COASTAL WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 79 91 78 / 20 10 50 40
STT 87 82 86 80 / 30 10 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
204 PM AST FRI MAY 6 2016

.SYNOPSIS...AT UPPER LEVELS...HIGH PRESSURE RIDGING BETWEEN
PUERTO RICO AND THE U.S. VIRGIN ISLANDS WILL BE SQUEEZED OVER TO
THE LEEWARD ISLANDS BY MONDAY...BUT AN APPROACHING TROUGH WILL
STALL OVER HISPANIOLA KEEPING SOUTHWEST WINDS AND LINES OF STRONG
DIVERGENCE OVER THE AREA THROUGH FRIDAY. HIGH PRESSURE RETURNS
OVER THE NEXT WEEKEND BUT AREAS OF DIVERGENCE WILL CONTINUE TO
MIGRATE THROUGH.

AT MID LEVELS...HIGH PRESSURE CONTINUES OVER THE CENTRAL ATLANTIC
NORTHEAST OF PUERTO RICO WHILE A PINCHED OFF LOW FROM A STRONG
LONG WAVE TROUGH ROTATES TO THE NORTHEAST AND DISSIPATES. WEAK
GRADIENTS OVER THE LOCAL AREA IN GENERALLY HIGH PRESSURE REMAIN
BEYOND THE FOLLOWING WEEK. MID LEVELS WILL BE CHARACTERIZED BY
MORE MOISTURE NEXT WEEK.

AT LOWER LEVELS...STRONG HIGH PRESSURE OVER THE CENTRAL ATLANTIC
WEAKENS CONSIDERABLY THROUGH THURSDAY AND THEN RECEDES TO THE
NORTHEAST TO RECHARGE. NEARLY SOUTHERLY WINDS BECOME MORE EAST
SOUTHEAST OR EAST EARLY IN THE WEEK ALLOWING SOME NORTH COAST
COOLING. MOISTURE INCREASES SLOWLY THROUGH TUESDAY AND THEN
BREATHES A LITTLE BEFORE INCREASING AGAIN THURSDAY AND FRIDAY OF
NEXT WEEK. A COLD FRONT WILL APPROACH THE AREA FROM THE
NORTHWEST...BUT IT APPEARS THAT ONLY THE PRE-FRONTAL BOUNDARY WILL
ACTUALLY AFFECT PUERTO RICO AND THE U.S. VIRGIN ISLANDS WITH
INCREASED SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...15 TO 25 KNOT WINDS FROM THE SOUTH SOUTHEAST ONLY
MADE THEIR PRESENCE FELT MORE AS WARMING AND MIXING BROUGHT DOWN
GUSTY WINDS THAT FOUGHT OFF THE SEA BREEZE THE ENTIRE DAY. A CAP
BETWEEN 5 AND 6 KFT ALSO SLOWED ANY CONVECTION THAT WAS NOT
SHEARED OFF AS WINDS TURNED WESTERLY AT 18 KFT. ALTHOUGH TOMORROW
WILL HAVE A LITTLE MORE MOISTURE AND SHOWERS...THE CAP WILL
INCREASE SOMEWHAT AND LIMIT THE SHOWER ACTIVITY. ON SUNDAY WE SEE
EVEN BETTER MOISTURE AND INSTABILITY AS THE BOUNDARY APPROACHES.
FINALLY ON MONDAY A BIT OF A CRESCENDO AS THE BOUNDARY REACHES
ITS CLOSEST APPROACH. MOISTURE IMPROVES AGAIN ON
WEDNESDAY...HOWEVER...AND SHOWERS WILL ALSO INCREASE. HENCE WE
MAY RESUME A WET WEEK AND SEE MORE POTENTIAL FOR URBAN AND SMALL
STREAM FLOODING. PART OF THIS INCREASE WILL BE OWED TO THE
MULTIPLE AREAS OF DIVERGENCE THAT WILL TRANSIT THE AREA FROM THE
SOUTHWEST BEGINNING MONDAY. HIGH CLOUDS AND WEAKER STABILITY
SHOULD PRECLUDE ANY EPISODE OF SEVERE WEATHER HOWEVER.

&&

.AVIATION...VFR COND AT ALL TAF SITES THROUGH FCST PRD. ISOLD SHRA
EN ROUTE BTW ISLANDS BUT MOSTLY CLR OVR LAND AREAS FM 07/00Z-07/09Z.
L/LVL WNDS FM SE-S BLO FL150...BCM SW-W ABV AND INCR W/HT. SFC WND
LGT AND VRB OVR LAND. NO SIG OPS WX HAZARDS ATTM.


&&

.MARINE...SEAS PEAK ON THE 8TH AND THE 10TH OF MAY AT THE OUTER
BUOY...REACHING ALMOST 7 FEET...HOWEVER SEAS SHOULD REMAIN BELOW 7
FEET THE ENTIRE PERIOD IN THE LOCAL OUTER ATLANTIC WATERS. THE
CARIBBEAN WILL GENERALLY BE A FOOT OR SO MORE TRANQUIL THAN THE
ATLANTIC.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 91 78 89 / 0 50 40 50
STT 82 86 80 86 / 30 40 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
505 AM AST SAT MAY 7 2016

.SYNOPSIS...HIGH PRESSURE RIDGE ALOFT WILL HOLD THROUGH
SUNDAY...WHICH WILL LIMIT ANY SIGNIFICANT CONVECTIVE DEVELOPMENT
DURING THE WEEKEND. A SOUTHERLY WIND FLOW WILL PROMOTE HIGHER THAN
NORMAL TEMPERATURES ACROSS THE NORTHERN SLOPES OF PUERTO RICO.

&&

.DISCUSSION...SOME SHOWERS WERE OBSERVED OVER THE ATLANTIC COASTAL
WATERS...WITH SOME AFFECTING SAINT THOMAS AND SAINT JOHN IN THE
U.S. VIRGIN ISLANDS. LOCAL AREA REMAINED UNDER THE INFLUENCES OF A
WEAK SURFACE HIGH PRESSURE AREA TO THE EAST AND AN UPPER TROUGH
AND FRONTAL BOUNDARY WEST OF THE AREA. THE COMBINATION OF THESE
FEATURES ARE PRODUCING A SOUTH WIND FLOW ACROSS THE REGION. AS A
RESULT...WARMER THAN NORMAL TEMPERATURES ARE EXPECTED ONCE AGAIN
THIS AFTERNOON MAINLY ALONG THE NORTHERN HALF OF PUERTO RICO.

FOR THE EARLY PART OF NEXT WEEK...THE AFORMENTIONED FRONTAL
BOUNDARY IS EXPECTED TO SLOWLY WEAKENS NORTH OF THE AREA.
HOWEVER...MOISTURE ASSOCIATED WITH IT IS EXPECTED TO MOVE ACROSS
THE REGION MONDAY AND TUESDAY...KEEPING HIGH CHANCES FOR SHOWERS
AND THUNDERSTORMS ACROSS THE REGION. AFTER WEDNESDAY...A RETURN TO
NORMAL TRADE WINDS IS EXPECTED...WITH NO SIGNIFICANT WEATHER
EVENTS FORECAST TO AFFECT THE REGION IN THE LONG TERM.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH
THE FORECAST PERIOD. VCTS AND PERIODS OF MVFR CONDITIONS WITH
MOUNTAIN OBSCURATIONS ARE EXPECTED OVER TJMZ AND TJBQ BTW 07/16 AND
07/22Z. LOW LEVEL WINDS WILL BE MAINLY SOUTHEAST AT AROUND 10 KNOTS
OVERNIGHT...INCREASING TO 10 TO 15 KTS AFTER 07/14Z WITH SEA BREEZE
VARIATIONS.

&&

.MARINE...SEAS BETWEEN 3 TO 5 FEET AND WINDS UP TO 15 KNOTS ARE
EXPECTED.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 92 78 87 76 / 20 20 20 40
STT 87 81 86 77 / 20 20 20 50

&&

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
226 PM AST SAT MAY 7 2016

.SYNOPSIS...A RIDGE WILL MOVE FROM OVER PUERTO RICO THIS AFTERNOON
TO THE ANEGADA PASSAGE ON SUNDAY. A TROUGH EXTENDING SOUTH OVER
CUBA WILL MOVE TO HAITI AND FORM A WEAK CUT-OFF LOW IN THE
CARIBBEAN SOUTH OF THE WINDWARD PASSAGE BY TUESDAY FORCING
MODERATE SOUTHWEST FLOW OVER THE LOCAL AREA. FLOW BECOMES MORE
ZONAL BY THE END OF THE WEEK AS HIGH PRESSURE FILLS IN OVER THE
CARIBBEAN.

AT MID LEVELS...HIGH PRESSURE WILL CONTINUE INTO MID-WEEK OVER THE
CENTRAL ATLANTIC. A TROUGH EXTENDS SOUTH OVER CUBA INTO THE
CARIBBEAN. THIS TROUGH WILL RECEDE TO THE NORTHEAST LEAVING A
WEAK RESIDUAL LOW PRESSURE OVER THE CENTRAL CARIBBEAN. MID LEVEL
MOISTURE WILL INCREASE TONIGHT AND CONTINUE MOIST WITH A SHORT
BREAK ON TUESDAY.

AT LOWER LEVELS...HIGH PRESSURE OVER THE CENTRAL ATLANTIC IS
IMPEDING THE PROGRESS OF A FRONTAL BOUNDARY THAT EXTENDS SOUTH
SOUTHWEST OVER HISPANIOLA. THAT BOUNDARY WILL DRIFT TOWARD PUERTO
RICO TONIGHT THROUGH SUNDAY WITH GOOD MOISTURE...BUT IS NOT
EXPECTED TO CROSS THE ISLAND. MOISTURE EXTENDING SOUTHWEST INTO
THE LEEWARD ISLANDS SUNDAY NIGHT WILL CROSS WEST OVER THE LOCAL
AREA MONDAY. HIGH PRESSURE WILL WEAKEN OVER THE ATLANTIC EVEN AS
HIGH PRESSURE MOVES OUT OF THE SOUTHEAST UNITED STATES INTO THE
WESTERN ATLANTIC EARLY NEXT WEEK. THAT HIGH WILL MOVE INTO THE
EASTERN ATLANTIC BY NEXT WEEKEND ALLOWING GRADIENTS TO WEAKEN AND
WINDS TO RETURN TO THE SOUTHEAST.

&&

.DISCUSSION...A FEW SHOWERS HAVE DEVELOPED OVER SOUTHWEST CENTRAL
PUERTO RICO AND A FEW MORE ARE EXPECTED AS WINDS REMAIN NEARLY
SOUTH SOUTHEAST AT THE SURFACE. MOISTURE AND SHOWERS WILL
GRADUALLY INCREASE FROM THE NORTHWEST UNTIL MIDDAY TOMORROW WHEN
SHOWERS DEVELOP OVER THE INTERIOR OF PUERTO RICO AND DRIFT NORTH
NORTHWEST. MOISTURE INCREASES OVERNIGHT SUNDAY NIGHT AND SOME
SHOWERS WILL CONTINUE...THOUGH MAINLY OVER THE LOCAL WATERS. THEN
ON MONDAY ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED
AS UPPER LEVEL DYNAMICS CONTINUE TO BE FAVORABLE OVER THE AREA
SUNDAY...MONDAY AND TUESDAY. MOISTURE PEAKS ON SUNDAY...REACHES A
MINIMUM ON WEDNESDAY...BUT NOT DRIER THAN TODAY...AND THEN
INCREASES AGAIN THURSDAY AND OVER THE WEEKEND.

THE RISK OF URBAN AND SMALL STREAM FLOODING APPEARS TO HAVE
DIMINISHED A LITTLE...BUT GOOD POTENTIAL STILL EXISTS FOR MONDAY
AND LATER THIS WEEK.

&&

.AVIATION...MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS
MOST TAF SITES THROUGH THE OVERNIGHT HOURS. HOWEVER...SHRA ARE EXPECTED
TO INCREASE ACROSS THE MONA PASSAGE AND ATLANTIC WATERS IMPACTING
MAINLY THE FLYING AREA OF JBQ/JMZ. BKN/OVC ABV FL100 WILL INCREASE
ON SUNDAY. SURFACE WINDS WILL BE MAINLY SOUTHEAST AT AROUND 10
KNOTS OVERNIGHT...BUT LOW LEVEL WINDS MAY REACH UP TO 30 KNOTS
ABOVE FL010.

&&

.MARINE...SEAS WILL INCREASE SOME DUE TO WINDS...BUT ARE NOT
EXPECTED TO REACH SMALL CRAFT ADVISORY CONDITIONS OVER A
SIGNIFICANT AREA ANY TIME TONIGHT OR NEXT WEEK.

&&

.EQUIPMENT...OUR TECHNICIAN ADVISES THAT WE HAVE NO ACCESS TO OUR
NOAA WEATHER RADIO SITE IN AGUAS BUENAS...AND WE WILL NOT BE ABLE
TO RESUME BROADCASTING UNTIL POWER IS RESTORED OR WE ARE ABLE TO
CONTACT THE SITE OWNERS.

&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 89 76 87 / 30 40 50 50
STT 79 86 77 85 / 20 30 60 60

[HurricaneFan]

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.