Caribbean - Central America Weather

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
237 PM AST WED OCT 21 2015

.SYNOPSIS...UPPER LEVEL TROUGH ACROSS THE EASTERN CARIBBEAN WILL
PERSIST THROUGH THE END OF THE WORK WEEK. THIS FEATURE WILL BE
ABSORBED BY A DEEP TROUGH WHICH IS EXPECTED TO ESTABLISH ACROSS
THE WESTERN ATLANTIC BY FRIDAY. AN INDUCED SURFACE TROUGH WILL
CONTINUE TO MAINTAIN SE WINDS ACROSS THE LOCAL ISLANDS DURING
THE NEXT FEW DAYS.

&&

.DISCUSSION...UNDER PRECIPITABLE WATER NEAR NORMAL VALUES AND
LIGHT SOUTHEASTERLY WINDS...CONTINUE TO EXPECT FAIR WEATHER CONDS
DURING THE MORNING HOURS WITH A FEW PASSING SHOWERS POSSIBLE
ACROSS THE U.S. VIRGIN ISLANDS AS WELL AS THE EAST AND SOUTHEAST
COASTAL AREAS OF PUERTO RICO....FOLLOWED BY AFTERNOON SHOWERS AND
THUNDERSTORMS DEVELOPING OVER AND NORTH OF THE CORDILLERA. THIS
WEATHER PATTERN SHOULD NOT CHANGE MUCH FOR THE REST OF THE WEEK.
DUE TO THE LIGHT WIND FLOW AND WETTING RAINS FROM PREVIOUS DAYS...
URBAN AND SMALL STREAM FLOODING LIKELY EACH AFTERNOON.

AS THE TROUGH TO OUR EAST IS ABSORBED BY THE DEVELOPING TROUGH
ACROSS THE WESTERN ATLANTIC...AN INDUCED SURFACE TROUGH WITH
ASSOCIATED LOW WILL PERSIST NORTH OF THE AREA. TROUGH ALOFT WILL
THEN LIFT AND A LOW LEVEL MOISTURE CONVERGENCE ZONE WILL BEGIN
SET UP ACROSS THE AREA. UNDER FAVORABLE UPPER LEVEL DYNAMICS...
TROPICAL MOISTURE AND LIGHT WINDS...A BETTER CHANCE FOR ORGANIZED
CONVECTION IS EXPECTED SUNDAY AND EARLY NEXT WORK WEEK. STAY
TUNED.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED ACROSS THE LOCAL FLYING
AREA. LOCAL AND DIURNAL EFFECTS WILL LEAD TO LATE AFTERNOON
CONVENTION OVER PARTS OF WESTERN AND NORTHERN PR. THIS WILL RESULT
IN VCTY SHRA/TSRA AT TJSJ...TJPS...TJBQ...AND TJMZ 21/19Z-21/22Z
WITH MOUNTAINS OBSCURATIONS AND BRIEF MVFR/IFR POSSIBLE. SURFACE
WIND 5-10 KTS WITH SEA BREEZE VARIATIONS DURING THE AFTERNOON
HOURS...BECOMING LIGHT AND VARIABLE AFT 21/23Z.

&&

.MARINE...A NORTHERLY SWELL WILL CONTINUE TO AFFECT THE ATLANTIC
WATERS AND MONA PASSAGE THROUGH THE LATE AFTERNOON HOURS...BUT
SLOWLY SUBSIDING OVERNIGHT. EXPECT SEAS OF 6 TO 8 FEET WITH
OCCASIONAL SEAS BETWEEN 9 AND 10 FEET EARLY IN THE FORECAST
PERIOD. AS NORTHERLY SWELL DIMINISHES OVERNIGHT...SEAS WILL
RETURN TO 3 TO 5 FEET.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 79 89 / 20 50 20 20
STT 79 88 79 88 / 30 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
541 AM AST THU OCT 22 2015

.SYNOPSIS...
UPPER LEVEL TROUGH ACROSS THE EASTERN CARIBBEAN WILL PERSIST THROUGH
THE END OF THE WORK WEEK. THIS FEATURE WILL BE ABSORBED BY A MID
TO UPPER LEVEL TROUGH WHICH WILL SINK FARTHER SOUTH ACROSS THE
REGION FROM THE WESTERN ATLANTIC BY FRIDAY. AN INDUCED INVERTED
SURFACE TROUGH EXTENDING ACROSS THE REGION WILL MAINTAIN LIGHT
SOUTHEASTERLY WINDS ACROSS THE FORECAST AREA DURING THE NEXT FEW
DAYS.

&&

.DISCUSSION...SATELLITE IMAGERY AND DOPPLER WEATHER RADAR
CONTINUE TO SHOW FEW SHALLOW LOW LEVEL CLOUDS AND MOSTLY LIGHT
PASSING SHOWERS ACROSS THE COASTAL WATERS. A FEW SHOWERS WILL
CONTINUE TO REACH PORTIONS OF THE EAST COASTAL SECTIONS OF PUERTO
RICO AND SOME OF THE ADJACENT ISLANDS DURING THE EARLY MORNING
HOURS. FOR THE REST OF THE DAY MOSTLY FAIR WEATHER SKIES SHOULD
PREVAIL. HOWEVER....THE LIGHT SOUTHEASTERLY WIND FLOW WILL AGAIN
GIVE WAY TO LOCAL SEA BREEZE VARIATIONS AND MOISTURE CONVERGENCE
LATER IN THE DAY. AFTERNOON SHOWERS AND THUNDERSTORMS ARE FORECAST
TO DEVELOP OVER PARTS OF THE WEST AND NORTH CENTRAL INTERIOR
SECTIONS OF PUERTO RICO. VERY LITTLE OF NO SHOWER ACTIVITY IS
EXPECTED ACROSS THE U.S VIRGIN ISLANDS TODAY AS MOSTLY SUNNY SKIES
WILL PREVAIL.

BY FRIDAY AND INTO THE WEEKEND...MODEL GUIDANCE STILL SUGGEST THAT
THE UPPER TROUGH OUR EAST WILL MERGE WITH THE AMPLIFYING TROUGH
ACROSS THE WESTERN ATLANTIC THEN LIFT NORTHWARDS ACROSS THE REGION
OVER THE WEEKEND. THE INDUCED SURFACE TROUGH ALONG WITH A DEVELOPING
LOW NORTH OF THE REGION WILL ALSO PERSIST THROUGH THE WEEKEND. THE
COMBINATION OF THE TROUGH ALOFT AND THE LOW LEVEL MOISTURE CONVERGENCE
ZONE INDUCED BY THE SURFACE TROUGH...WILL SUPPORT UNSTABLE CONDITIONS
FOR THE WEEKEND AND POSSIBLY INTO THE EARLY PART OF NEXT WEEK. THE EXPECTED
MOISTURE ADVECTION AND LIGHT WINDS WILL ALLOW FOR A BETTER CHANCE FOR
ORGANIZED CONVECTION ACROSS THE ISLANDS AND COASTAL WATERS ESPECIALLY
ON SUNDAY AND MONDAY. THEREFORE URBAN AND SMALL STREAM FLOODING WILL
REMAIN POSSIBLE EACH DAY IN ISOLATED AREAS BUT MAINLY ACROSS PUERTO
RICO.

&&

.AVIATION....MOSTLY VFR CONDITIONS EXPECTED THIS MORNING ACROSS
THE LOCAL FLYING AREA WITH VCSH ACROSS THE EASTERN TERMINALS OF TIST
AND TISX AND TJSJ. SURFACE WIND WILL REMAIN LIGHT/VARIABLE UNTIL
22/13Z...BECOMING FROM ESE AND GRADUALLY INCREASING TO 5-10 KTS WITH
SEA BREEZE VARIATIONS AFTER 22/14. LOCAL AND DIURNAL EFFECTS WILL
LEAD TO AFTERNOON SHOWERS AND THUNDERSTORMS OVER PARTS OF WESTERN
AND NORTHER HALF OF PUERTO RICO...ALONG CORDILLERA CENTRAL...AND
VCTY TJSJ...TJPS...TJBQ...AND TJMZ FROM 22/18Z-22/22Z WITH MOUNTAINS
OBSCURATIONS AND ISOLATED TSRA/SHRA INDUCING BRIEF PERIODS OF
MVFR/IFR CONDITIONS.

&&

.MARINE...
MODEL GUIDANCE CONTINUED TO UNDERESTIMATE THE NORTHERLY SWELL
ACTION AS SUGGESTED BY THE LOCAL AND OFFSHORE BUOYS TO THE NORTH.
RECENT DATA FROM BUOY 41053 AND 41043 BOTH SUGGEST THE SWELL SLOWLY
SUBSIDING...BUT STILL AROUND 7 FEET AT 11 SECS. THEREFORE IT WAS
DECIDED TO KEEP THE HIGH SURF ADVISORY AND STRONG RIP CURRENT
STATEMENTIN EFFECT UNTIL 8 AM AST THIS MORNING....PENDING
FURTHER REVISION/UPDATE IF NECESSARY. LIKEWISE...SMALL CRAFT
ADVISORIES WILL REMAIN IN EFFECT FOR MOST OF THE ATLANTIC WATERS
AND LOCAL PASSAGES UNTIL THIS AFTERNOON.

&&

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
323 PM AST THU OCT 22 2015

.SYNOPSIS...
A MID TO UPPER LEVEL TROUGH WILL CONTINUE TO BUILD FROM THE WEST
OF THE REGION THROUGH THE END OF THE WORK WEEK AND INTO THE
WEEKEND. SURFACE MOISTURE WILL INCREASE DURING THE REST OF THE
WEEK AND INTO THE NEXT WEEK. AN INDUCED INVERTED SURFACE TROUGH
EXTENDING ACROSS THE REGION WILL MAINTAIN LIGHT SOUTHEASTERLY
WINDS ACROSS THE FORECAST AREA DURING THE NEXT FEW DAYS.

&&

.DISCUSSION...
UNDER THE PREVAILING EAST SOUTHEASTERN SURFACE WIND FLOW EXPECT WARM
AND HUMID CONDITIONS ACROSS THE REGION DURING THE REST OF THE WORK
WEEK AND INTO THE WEEKEND. A RECORD OF HIGH TEMPERATURE WAS SET AT
THE LUIS MUNOZ MARIN AIRPORT TODAY...THE PREVIOUS RECORD WAS 93
DEGREES SET BACK IN 1982. THUNDERSTORMS ARE DEVELOPING OVER THE
MUNICIPALITIES OF THE METROPOLITAN AREA AND NORTH CENTRAL PUERTO
RICO. AS THE AFTERNOON CONTINUES...EXPECT SHOWERS AND
THUNDERSTORMS MAINLY NORTH...WEST AND ALONG THE CORDILLERA CENTRAL
AT LEAST UNTIL EVENING HOURS. THE BUILDING TROUGH ALOFT WILL
PROVIDE ENOUGH INSTABILITY TO ENHANCE SHOWERS AND THUNDERSTORM
ACTIVITY TODAY AND TOMORROW. IN ADDITION AS THE SURFACE MOISTURE
INCREASE AND THE TROUGH ALOFT BUILDS OVER THE REGION...THE
LIKELIHOOD FOR MODERATE TO STRONG THUNDERSTORMS ARE EXPECTED TO
INCREASE. THEREFORE...FLOODING... MUDSLIDES AND FREQUENT LIGHTNING
ACTIVITY IS LIKELY TO OCCURS WITH THIS ACTIVITY OVER AND NORTH OF
THE CORDILLERA DURING THE WEEKEND.

MODEL GUIDANCE ARE SUGGESTING A SHARP INCREASE IN THE AVAILABLE
SURFACE MOISTURE DURING THE NEXT FIVE DAYS. AS A RESULT THE
COMBINATION OF FAVORABLE UPPER LEVEL DYNAMICS...INCREASING
TROPICAL MOISTURE AND LIGHT WINDS...A BETTER CHANCE FOR ORGANIZED
CONVECTION IS EXPECTED DURING THE WEEKEND AND EARLY NEXT WORK
WEEK.

&&

.AVIATION...BRIEF PERIODS OF MVFR CONDS WITH MOUNTAIN OBSCURATIONS
ARE POSSIBLE AT JSJ/JMZ AND JBQ IN SHRA/TSRA TILL 22/23Z. VRF CONDS
EXPECTED AT ALL TAF SITES AFT 22/23Z...WITH LIGHT AND VARIABLE
WINDS. ANOTHER ROUND OF SHRA/TSRA EXPECTED TOMORROW ALONG AND
NORTH OF THE CORDILLERA.

&&

.MARINE...A NORTHERLY SWELL WILL CONTINUE TO SLOWLY SUBSIDE THIS
EVENING AND INTO THE OVERNIGHT HOURS. THE RISK FOR RIP CURRENTS
STILL HIGH ACROSS THE ATLANTIC BEACHES. BUOYS DATA INDICATED SEAS
AT 3 TO 7 FEET WITH OCCASIONAL SEAS UP TO 9. AN SMALL CRAFT
ADVISORY CONTINUES IN EFFECT FOR THE ATLANTIC WATERS AND LOCAL
PASSAGES.

&&

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
545 AM AST FRI OCT 23 2015

.SYNOPSIS...
MID TO UPPER LEVEL LEVEL TROUGH JUST WEST OF THE AREA WILL
CONTINUE TO AMPLIFY AND SPREAD EASTWARD ACROSS THE NORTHEASTERN
CARIBBEAN THOUGH THE WEEKEND. THIS WILL RESULT IN CONTINUED
DESTABILIZATION OF THE UPPER LEVEL ATMOSPHERE AND DEPLETION OF
LOCAL CAP INVERSION TODAY AND OVER THE NEXT FEW DAYS. AN ELONGATED
INVERTED SURFACE TROUGH EXTENDING ACROSS THE REGION INTO THE SOUTHWEST
ATLANTIC WILL MAINTAIN LIGHT SOUTHEASTERLY TRADE WINDS. THIS WILL
HELP CREATE A MOIST CONVERGENCE ZONE ACROSS THE FORECAST AREA
BEGINNING TODAY AND CONTINUING INTO THE EARLY PART OF NEXT WEEK
WITH PWAT VALUES FORECAST TO PEAK AROUND TWO INCHES OR SO LATE
SUNDAY INTO MONDAY.

&&

.DISCUSSION...RECENT SATELLITE IMAGERY AND DOPPLER WEATHER RADAR
SHOWED LOW LEVEL CONVERGENCE ZONE SETTING UP ACROSS THE REGION
WITH CLUSTERS OF CONVECTION NOW ACROSS THE NORTHWEST QUADRANT OF
THE OFFSHORE COASTAL WATERS....AND SOME SHOWERS DEVELOPING ACROSS
THE COASTAL WATERS BETWEEN EASTERN PUERTO RICO AND THE WATERS
SURROUNDING THE VIRGIN ISLANDS. FOR THE REST OF TODAY...THE COMBINATION
OF BREEZE VARIATIONS...AND THE UPPER LEVEL TROUGH LIFTING ACROSS THE
REGION WILL SUPPORT SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT ACROSS
THE ISLANDS DURING THE AFTERNOON HOURS. THIS ACTIVITY SHOULD BE FOCUSED
MAINLY ACROSS PARTS OF THE INTERIOR AND NORTHERN HALF OF PUERTO RICO
INCLUDING PORTIONS OF THE SAN JUAN METRO AREA. SOME OF THE ACTIVITY
MAY BE ENHANCED WITH THE POSSIBILITY OF ISOLATED BUT STRONG THUNDERSTORMS
IN SOME AREAS. THIS WILL LEAD TO URBAN AND SMALL STREAM FLOODING.

OVER THE WEEKEND AND INTO EARLY NEXT WEEK...MODEL GUIDANCE SUGGEST
WINDS TO CONTINUE TO VEER AND BECOME MORE SOUTHERLY BUT REMAIN LIGHT.
THEREFORE EXPECT DIURNAL CONVECTION TO CONTINUE TO BE FOCUSED ACROSS
THE NORTHERN HALF AND EAST SECTIONS OF PUERTO RICO AND OVER PORTIONS
OF THE VIRGIN ISLANDS. SO FAR MODELS STILL SUGGEST THE BEST POTENTIAL
FOR BETTER ORGANIZED CONVECTION IS ON SUNDAY AND INTO EARLY NEXT WEEK.

&&

.AVIATION...PREVAILING VFR CONDITIONS EXPECTED THIS MORNING ACROSS
THE LOCAL FLYING AREA WITH VCSH ACROSS THE EASTERN TERMINALS OF
TIST...TISX AND TJSJ. SURFACE WIND WILL REMAIN LIGHT/VARIABLE UNTIL
23/13Z...BECOMING FROM ESE AND GRADUALLY INCREASING TO 5-10 KTS WITH
SEA BREEZE VARIATIONS AFTER 23/14. INSTABILITY ACROSS THE REGION IN
COMBINATION WITH LOCAL AND DIURNAL EFFECTS WILL LEAD TO AFTERNOON
SHOWERS AND THUNDERSTORMS OVER PARTS OF NORTHERN HALF AND WESTERN
PUERTO RICO...ALONG CORDILLERA CENTRAL...AND VCTY TJSJ...TJBQ...AND
TJMZ FROM 23/18Z-23/22Z WITH MOUNTAINS OBSCURATIONS AND ISOLATED
TSRA/SHRA INDUCING PERIODS OF MVFR OR EVEN IFR CONDITIONS.


&&

.MARINE...RECENT DATA FROM THE SURROUNDING AND OFFSHORE BUOYS SUGGEST
MARINE CONDITIONS HAVE CONTINUED TO IMPROVE ACROSS THE ATLANTIC WATERS
AND LOCAL PASSAGES...AS THE NORTHERLY SWELLS CONTINUE TO SUBSIDE. SMALL
CRAFT SHOULD HOWEVER EXERCISE CAUTION ACROSS THE LOCAL ATLANTIC WATERS
DUE TO SEAS OF 4 TO 6 FEET. FOR LOCAL BEACHGOERS AND VISITORS THERE
IS A MODERATE RISK OF RIP CURRENTS FOR ALL OF THE NORTH FACING BEACHES
OF PUERTO RICO INCLUDING CULEBRA AND SAINT THOMAS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 76 89 79 / 20 20 20 30
STT 88 78 88 78 / 40 30 30 30

&&

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
525 AM AST SAT OCT 24 2015

.SYNOPSIS...A MID TO UPPER LEVEL TROUGH WILL REMAIN OVER THE
REGION FOR THE NEXT SEVERAL DAYS...DEVELOPING INTO AN UPPER LEVEL
LOW NORTH OF THE REGION TONIGHT. THE LOCAL ISLANDS WILL REMAIN IN
A SURFACE COL UNTIL SUNDAY. THESE FEATURES WILL MAINTAIN A LIGHT
AND VARIABLE TRADE WINDS ACROSS THE REGION. TROP1CAL MOISTURE
WILL MAINTAIN A VERY UNSTABLE WEATHER PATTERN ACROSS THE REGION
UNTIL THE MIDDLE OF THE UPCOMING WEEK.

&&

.DISCUSSION...SHOWER AND THUNDERSTORM ACTIVITY PREVAILED ACROSS
THE SURROUNDING WATERS OVERNIGHT INTO EARLY THIS MORNING.
HOWEVER...AFTER THE PREVIOUS AFTERNOON SHOWER AND THUNDERSTORM
ACTIVITY ACROSS MOST PART OF PUERTO RICO...NO SIGNIFICANT
PRECIPITATION WAS DETECTED OVER LAND AREAS OVERNIGHT.

AN UPPER LEVEL TROUGH ACROSS THE REGION WILL CONTINUE TO DIG
SOUTHWARD ACROSS THE CENTRAL CARIBBEAN TODAY...DEVELOPING INTO AN
UPPER LEVEL LOW JUST NORTH OF THE REGION TONIGHT AND TOMORROW.
OVER THE REST OF THE WEEKEND AND INTO THE MIDDLE OF THE UPCOMING
WEEK...MODEL GUIDANCE SUGGEST WINDS TO CONTINUE LIGHT AND
VARIABLE. AS THIS HAPPENS DEEP TROPICAL MOISTURE WILL REMAIN OVER
THE LOCAL ISLANDS INDUCING THE DEVELOPMENT ACTIVE WEATHER EACH
AFTERNOON OVER LAND AREAS AND OVERNIGHT ACROSS THE SURROUNDING
COASTAL WATERS. SO FAR MODELS STILL SUGGEST THE BEST POTENTIAL
FOR BETTER ORGANIZED CONVECTION IS ON SUNDAY AND MONDAY...WITH
LIGHT WINDS MAINTAINING THE CONVECTION OVER THE SAME AREA FOR A
LONG PERIOD OF TIME...INCREASING THE RAINFALL RATE.

&&

.AVIATION...TSRA REMAIN ACTIVE OVER WATERS NE-SE OF SAN JUAN AND OUT
UP TO 200 NM. TSRA WILL NOT COMPLETELY DIE DOWN TONIGHT AS OLD
FRONTAL BOUNDARY REMAINS NEARBY AND RETURNS TO PR TOMORROW. AFT
24/15Z...SHRA/TSRA WILL RE-DEVELOP OVER INTERIOR PR BRINGING
MVFR/IFR CONDS AND MTN OBSCURATIONS. BRIEF MVFR AND VCNTY TSRA
EXPECTED AT TAF SITES TJSJ...TJPS...TJMZ...TJBQ...BUT AGAIN PCPN LTD
ON COASTLINE. SOME SCT TSRA ARND TIST AND TISX. WINDS ALF UP TO
FL060 NW LESS THAN 10 KT AND W LESS THAN 15 KT UP TO FL130. BCMG BY
24/18Z SW AT FL010 5 KT INCRG TO 20 KT BY FL120. NOTE: WEAK JET
NOTED ARND FL185...SW/28 KT.

&&

.MARINE...MARINERS CAN EXPECT SEAS BELOW 5 FEET AND WINDS BELOW 15
KNOTS. HOWEVER...WATER SPOUTS AND GUSTY WINDS ARE LIKELY IN AND
NEAR THUNDERSTORM ACTIVITY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 76 88 76 / 50 30 50 50
STT 88 78 88 78 / 50 50 50 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
256 PM AST SAT OCT 24 2015

.SYNOPSIS...A MID TO UPPER LEVEL TROUGH WILL REMAIN OVER THE
REGION FOR THE NEXT SEVERAL DAYS...DEVELOPING INTO AN UPPER LEVEL
LOW NORTH OF THE REGION TONIGHT. THE LOCAL ISLANDS WILL REMAIN IN
A SURFACE COL UNTIL SUNDAY. THESE FEATURES WILL MAINTAIN A LIGHT
AND VARIABLE TRADE WINDS ACROSS THE REGION. TROP1CAL MOISTURE
WILL MAINTAIN A VERY UNSTABLE WEATHER PATTERN ACROSS THE REGION
UNTIL THE MIDDLE OF THE UPCOMING WEEK.


.DISCUSSION...ONCE AGAIN AFTERNOON CONVECTION BEGAN TO DEVELOP
ALONG THE CORDILLERA CENTRAL AND THEN SLOWLY MOVING TO OTHER PARTS
OF THE ISLANDS, THE FIRST SHOWERS AND THUNDERSTORMS WERE LOCATED
OVER THE EASTERN TIP OF PUERTO RICO BUT LATER ON OVER OTHER
SHOWERS AND THUNDERSTORMS MANLY ALONG THE CORDILLERA CENTRAL.
ALTHOUGH THESE CONVECTIVE ACTIVITY IS EXPECTED TO LOOSE INTENSITY
THROUGH THE AFTERNOON HOURS...CONDITIONS ARE FAVORABLE FOR THEM TO
CONTINUE THROUGH THE EVENING HOURS.

MODEL GUIDANCE SUGGEST WINDS TO CONTINUE LIGHT AND VARIABLE. AS
THIS HAPPENS DEEP TROPICAL MOISTURE WILL REMAIN OVER THE LOCAL
ISLANDS INDUCING THE DEVELOPMENT ACTIVE WEATHER EACH AFTERNOON
OVER LAND AREAS AND OVERNIGHT ACROSS THE SURROUNDING COASTAL
WATERS. SO FAR MODELS STILL SUGGEST THE BEST POTENTIAL FOR BETTER
ORGANIZED CONVECTION IS ON SUNDAY AND MONDAY...WITH LIGHT WINDS
MAINTAINING THE CONVECTION OVER THE SAME AREA FOR A LONG PERIOD OF
TIME...INCREASING THE RAINFALL RATE. SOILS ARE SATURATED DUE TO
HEAVY SHOWER ACTIVITY...INCREASING THE FLOOD POTENTIAL MAINLY
ALONG THE INTERIOR SECTIONS OF PUERTO RICO.

&&

.AVIATION...TEMPO MVFR/IFR CONDS POSSIBLE AT TJSJ WITH TSRA. LATER
THIS AFTERNOON. VCTS LIKELY AT TJMZ...TJBQ AND TJPS BETWEEN 19-22Z.
LIGHT SOUTHERLY WINDS AT SFC. WSW WINDS AT 10-25 KT JUST ABV SFC
TO FL200.

&&

.MARINE...MARINERS CAN EXPECT SEAS BELOW 5 FEET AND WINDS BELOW 15
KNOTS. HOWEVER...WATER SPOUTS AND GUSTY WINDS ARE LIKELY IN AND
NEAR THUNDERSTORM ACTIVITY. ANOTHER SWELL EVENT WILL BE AFFECTING
THE ATLANTIC LOCAL WATERS ON FRIDAY.



&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 88 76 87 / 30 50 50 50
STT 78 88 78 86 / 50 50 50 50

[msbee]

S Maarten received some nice rain today. We had a thunderstorm this morning and one this afternoon. I heard though that the rain did not reach all sections of the island.. But our cistern is overflowing.
Currently it is thundering and dark to the South. Everyone here is loving the weather after our months long drought.

Barbara

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
441 AM AST SUN OCT 25 2015

.SYNOPSIS...MID TO UPPER LEVEL LOW NORTH OF PUERTO RICO AND AN
ASSOCIATED UPPER TROUGH EXTENDING ACROSS THE CENTRAL CARIBBEAN
AND CENTRAL AMERICA WILL DIG FURTHER SOUTH ACROSS THE REGION UNTIL
THE MIDDLE OF THE WEEK. AN INDUCE SURFACE TROUGH WILL REMAINS
ACROSS THE REGION UNTIL AT LEAST MONDAY. THESE FEATURES WILL
MAINTAIN A LIGHT AND VARIABLE LOW LEVEL WIND FLOW AND AN UNSTABLE
WEATHER ENVIRONMENT FOR THE NEXT CUOPLE OF DAYS.

&&

.DISCUSSION...NUMEROUS SHOWERS AND STRONG THUNDERSTORMS DEVELOPED
OVER CORDILLERA CENTRAL LAST AFTERNOON...PRODUCING HEAVY RAINS
OVER EASTERN INTERIOR AND CENTRAL SECTIONS OF PUERTO RICO. RAIN
GAGES OVER THOSE AREAS MEASURED BETWEEN 3 TO 6 INCHES OF RAIN
SPECIALLY OVER LA PLATA AND CARRAIZO BASINS. THIS IMPRESSIVE
SHOWER AND THUNDERSTORM ACTIVITY DIMINISHED RAPIDLY AFTER SUNSET
LEAVING ONLY PARTLY CLOUDY SKIES WITH LIMITED SHOWER ACTIVITY OVER
LAND AREAS OVERNIGHT INTO EARLY MORNING HOURS. HOWEVER...SHOWERS
AND THUNDERSTORMS SOME WITH FREQUENT LIGHTNINGS PERSISTED ACROSS
THE SURROUNDING WATERS OVERNIGHT INTO EARLY THIS MORNING.

A MID TO UPPER LEVEL LOW NORTH OF THE REGION AND AN ASSOCIATED
TROUGH EXTENDING ACROSS THE CENTRAL CARIBBEAN AND THEN ACROSS
CENTRAL AMERICA...WILL CONTINUE TO DIG FURTHER SOUTHWARD ACROSS
THE LOCAL ISLANDS TODAY AND DURING THE FIRST PART OF THE WEEK. AT
THE SAME TIME AN INDUCE SURFACE TROUGH REMAIN ACROSS THE REGION.
THESE FEATURES WILL MAINTAIN A LIGHT AND VARIABLE LOW LEVEL WIND
FLOW AND VERY UNSTABLE CONDITIONS ACROSS THE REGION FOR THE NEXT
COUPLE OF DAYS. DEEP TROPICAL MOISTURE WILL REMAIN OVER THE LOCAL
ISLANDS INDUCING THE DEVELOPMENT OF VERY ACTIVE WEATHER OVER LAND
AREAS EACH AFTERNOON AND OVERNIGHT ACROSS THE SURROUNDING COASTAL
WATERS. SO FAR MODELS STILL SUGGEST THE BEST POTENTIAL FOR BETTER
ORGANIZED CONVECTION IS TODAY AND MONDAY...WITH LIGHT WINDS
MAINTAINING THE CONVECTION OVER THE SAME AREA FOR A LONG PERIOD OF
TIME...INCREASING THE RAINFALL RATE.

&&

.AVIATION...MAINLY VFR OVERNIGHT AND EARLY SUNDAY MORNING ACROSS ALL
TERMINALS. HOWEVER...VCSH STILL POSSIBLE FROM TIME TO TIME ACROSS
THE LEEWARD ISLANDS TERMINALS. THEN...BY 25/14Z SHRA/TSRA SHOULD
START TO DEVELOP ONCE AGAIN ACROSS THE FLYING AREA. MAINLY ALONG THE
MOUNTAIN RANGES OF PR...AND OVER THE CARIBBEAN WATERS/ANEGADA
PASSAGE. IMPACTING MAINLY THE NORTH AND EASTERN PR TERMINALS AND THE
USVI/LEEWARD TERMINALS THRU THE END OF THE FCST PERIOD. THE LATEST
25/00Z TJSJ UPPER AIR SOUNDING INDICATED LIGHT SOUTH WINDS FROM SFC
UP TO 3 KFT AND WESTERLIES ABOVE...WITH 10-31 KNOTS BETWEEN FL100-
200.

&&

.MARINE...MARINERS CAN EXPECT SEAS BELOW 5 FEET AND WINDS UP TO 15
KNOTS. HOWEVER...WATER SPOUTS AND GUSTY WINDS ARE LIKELY IN AND
NEAR THUNDERSTORM ACTIVITY. ANOTHER SWELL EVENT WILL BE AFFECTING
THE ATLANTIC LOCAL WATERS ON FRIDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 74 87 78 / 60 50 50 40
STT 87 77 87 78 / 50 50 50 40

[cycloneye]

The drought in Puerto Rico is ending as plenty of rain is falling thanks to a trough nearby bringing deep moisture.

Here is Carraizo dam that had to open one gate.

[cycloneye]

Until Monday night flood watch.

FLOOD WATCH
NATIONAL WEATHER SERVICE SAN JUAN PR
745 AM AST SUN OCT 25 2015

...FLASH FLOODING POTENTIAL IN EFFECT THROUGH MONDAY NIGHT...

PRZ001>013-VIZ001-002-260000-
/O.NEW.TJSJ.FF.A.0002.151025T1200Z-151027T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN JUAN AND VICINITY-NORTHEAST-SOUTHEAST-EASTERN INTERIOR-
NORTH CENTRAL-CENTRAL INTERIOR-PONCE AND VICINITY-NORTHWEST-
WESTERN INTERIOR-MAYAGUEZ AND VICINITY-SOUTHWEST-CULEBRA-VIEQUES-
ST. THOMAS/ST. JOHN/ADJACENT ISLANDS-ST CROIX-
INCLUDING THE CITIES OF...SAN JUAN...CAROLINA...FAJARDO...
HUMACAO...GUAYAMA...ARROYO...YABUCOA...SALINAS...COCO...CAGUAS...
ARECIBO...VEGA BAJA...DORADO...COAMO...COROZAL...AIBONITO...
VILLALBA...JAYUYA...PONCE...AGUADILLA...ISABELA...HATILLO...
QUEBRADILLAS...UTUADO...SABANA GRANDE...LARES...ADJUNTAS...
HORMIGUEROS...MOCA...AGUADA...LUYANDO...CABO ROJO...LAJAS...
CULEBRA...ESPERANZA...ANNA`S RETREAT...CHARLOTTE AMALIE...
CHARLOTTE AMALIE EAST...CHARLOTTE AMALIE WEST...CRUZ BAY...
CHRISTIANSTED...FREDERIKSTED...FREDERIKSTED SOUTHEAST...
GROVE PLACE
745 AM AST SUN OCT 25 2015

...FLASH FLOOD WATCH IN EFFECT THROUGH MONDAY EVENING...

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* FLASH FLOOD WATCH FOR ALL PUERTO RICO AND U.S. VIRGIN ISLANDS

* THROUGH MONDAY NIGHT

* AN UPPER LEVEL LOW JUST NORTHWEST OF THE LOCAL REGION COMBINED
WITH ABUNDANT MOISTURE WILL CONTINUE TO ENHANCE THE POTENTIAL OF
FLOODING RAINS ACROSS PUERTO RICO AND THE U.S VIRGIN ISLANDS
THROUGH MONDAY. SATURATED SOILS FROM PREVIOUS DAYS RAINFALL WILL
ALSO HELP TO MAINTAIN A HIGH POTENTIAL FOR FLASH FLOODING AND
MUDSLIDES THROUGH EARLY NEXT WEEK.

* ANY ADDITIONAL HEAVY RAINFALL COULD LEAD TO FLASH FLOODING...
ESPECIALLY IN AREAS WHERE RAINFALL HAS OCCURED IN RECENT DAYS.
ALTHOUGH...THE RAINFALL WILL NOT BE CONTINUOUS BUT RAPID
INTENSIFICATION OF STORMS IS LIKELY IN THE AFTERNOON HOURS.

* RESIDENTS AND VISITORS ALONG RIVER BANKS SHOULD REMAIN ALERT AND
MONITOR FOR HEAVY RAINFALL IN THE HEADWATERS OF RIVERS AND TRIBUTARIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$

ER/RAM/DS

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
304 PM AST SUN OCT 25 2015

.SYNOPSIS...MID TO UPPER LEVEL LOW NORTH OF PUERTO RICO AND
ASSOCIATED UPPER TROUGH EXTENDING INTO CENTRAL AMERICA WILL
CONTINUE TO AMPLIFY INTO THE EASTERN CARIBBEAN UNTIL AT LEAST LATE
WEDNESDAY NIGHT. AN INDUCE SURFACE TROUGH WILL LINGER ACROSS THE
REGION THRU LATE MONDAY NIGHT. THESE FEATURES WILL MAINTAIN A
LIGHT AND VARIABLE LOW LEVEL WIND FLOW AND FAVORABLE ENVIRONMENTAL
CONDITIONS TO GENERATE SHOWERS AND THUNDERSTORMS THRU AT LEAST
WEDNESDAY AFTERNOON. SURFACE HIGH PRESSURE WILL ESTABLISH BY MID
WEEK OVER THE CENTRAL ATLANTIC GENERATING MORE EASTERLY WINDS
ACROSS THE REGION.

&&

.DISCUSSION...ANOTHER ACTIVE AFTERNOON WAS OBSERVED ACROSS PUERTO
RICO AND THE USVI...ESPECIALLY OVER ST. CROIX. AFTER A FLASH FLOOD
WATCH WAS ISSUED EARLIER THIS MORNING...SEVERAL FLOOD ADVISORIES
AND FLASH FLOOD WARNINGS WERE ISSUED JUST AFTER 1 PM AST FOR MUCH
OF THE EASTERN HALF OF PR. THRU MID AFTERNOON...BETWEEN 1 TO 3
INCHES OF RAIN WERE ESTIMATED BY THE DOPPLER RADAR AND RAIN GAGES
ACROSS THE CARRAIZO...CIBUCO AND LA PLATA BASIN. FOR THE REST OF
THE AFTERNOON AND INTO THE EARLY EVENING EXPECT SHOWERS AND
THUNDERSTORMS TO CONTINUE DEVELOPING OVER THE MOUNTAIN RANGES OF
PR...INCREASING THE RUNOFF AND FLOODING THREAT OVER THE EASTERN
HALF OF PR.

AS MID/UPPER LEVEL LOW PULLS SLOWLY NORTH OF THE AREA DURING THE
FIRST PART OF THE WEEK. DEEP TROPICAL MOISTURE WILL MOVE OVER THE
FORECAST AREA THRU AT LEAST TUESDAY AFTERNOON. THIS WILL INDUCE THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE SURROUNDING
COASTAL WATERS AND ALONG THE MOUNTAIN RANGES OF PR EACH DAY. WITH
ALREADY SATURATED SOILS AND ENOUGH RUNOFF...EXPECT RIVERS TO REACT
QUICKLY TO ANY ADDITIONAL RAINFALL OVER THE EASTERN/SOUTHEAST AND
NORTH CENTRAL AREAS OF PUERTO RICO. ALSO...MUDSLIDES ARE LIKELY IN
AREAS OF STEEP TERRAIN. BY THE SECOND PART OF THE WEEK...AS WINDS
TURN MORE EASTERLY DUE TO SFC HIGH PRESSURE OVER THE CENTRAL
ATLANTIC...AFTERNOON DIURNAL CONVECTION IS EXPECTED MAINLY OVER
THE WESTERN HALF OF THE ISLAND.

A FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL AT LEAST MONDAY NIGHT.
PLEASE REFER TO LATEST FLASH FLOOD WATCH (FFASJU) FOR MORE INFORMATION.

&&

.AVIATION...SHRA/TSRA WILL CONTINUE OVER THE FLYING AREA THRU THE
FORECAST PERIOD. IMPACTING MAINLY THE NORTH AND EASTERN PR AND THE
USVI/LEEWARD THRU TONIGHT. AS A RESULT...EXPECT TEMPO MVFR/IFR CONDS
IN AND AROUND TJSJ...TISX...TIST AND THE LEEWARD TERMINALS THRU AT
LEAST 22Z. MOUNTAIN OBSCURATION ALSO LIKELY THE REST OF TODAY. LIGHT
SOUTH WINDS FROM SFC UP TO 3 KFT AND WESTERLIES ABOVE...WITH 10-30
KNOTS BETWEEN FL100-200.

&&

.MARINE...MARINE CONDITIONS SHOULD NOT SEE ANY SIGNIFICANT CHANGE
OVER THE NEXT SEVERAL DAYS AS SEAS OF 3-5 FEET ARE EXPECTED MAINLY
OVER THE OFFSHORE WATERS. NEARSHORE SEAS SHOULD REMAIN BETWEEN 1-3
FEET. EAST TO SOUTHERLY WINDS SHOULD CONTINUE BETWEEN 10-15 KNOTS
WITH HIGHER GUSTS NEAR SHOWERS AND THUNDERSTORMS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 87 78 88 / 50 50 40 40
STT 77 87 78 88 / 50 50 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
546 AM AST MON OCT 26 2015

.SYNOPSIS...AT UPPER LEVELS...LOW PRESSURE NORTH OF THE MONA
CHANNEL WILL FILL DURING THE NEXT SEVERAL DAYS AND DROP SOUTH
TUESDAY NIGHT...BEFORE RETURNING NORTH AND RE-UNITING WITH THE
SOUTHWEST FLOW TO THE NORTH OF THE AREA. A WEAK TROUGH WILL REMAIN
TO THE EAST OF THE AREA AS HIGH PRESSURE BUILDS OVER THE WESTERN
CARIBBEAN LATER THIS WEEK.

AT MID LEVELS...A LOW WILL GRADUALLY FILL NORTH OF THE DOMINICAN
REPUBLIC AND THE MONA CHANNEL DURING THE WEEK. HIGH PRESSURE WILL
CONTINUE TO THE NORTHEAST OF THE AREA. MID LEVELS ARE RICH IN
MOISTURE BUT WILL DRY SOMEWHAT DURING THE WEEK. HIGH PRESSURE WILL
BUILD OVER THE BAHAMA ISLANDS OVER THE WEEKEND.

AT LOWER LEVELS...INDUCED TROUGHINESS FROM THE UPPER LEVEL LOW
PRESSURE WILL BRING UP RICH MOISTURE IN SOUTHERLY FLOW TODAY AND
TOMORROW. ON TUESDAY NIGHT FLOW WILL CHANGE TO THE EAST...BUT LOW
LEVEL MOISTURE WILL CONTINUE. SHOWERS AND THUNDERSTORMS WILL
CONTINUE IN THEIR DAILY PATTERN BUT SHOULD DELIVER LESS RAINFALL
TOWARD THE END OF THE WEEK. ANOTHER SHOT OF MOISTURE IS EXPECTED
ON SUNDAY.

&&

.DISCUSSION...SHOWERS TAPERED OFF OVERNIGHT OVER ALL BUT THE
NORTHEAST CORNER OF THE FORECAST AREA. THERE...THUNDERSTORMS
CONTINUED THROUGH MUCH OF THE NIGHT. SHOWERS RECENTLY FORMED SOUTH
OF MONA ISLAND AND SHOWERS ARE EXPECTED TO DEVELOP DURING THE
MORNING HOURS OVER PUERTO RICO. MOISTURE IS RICH AND PRECIPITABLE
WATER TODAY IS EXPECTED TO REACH ITS HIGHEST VALUE...OF THE SEVEN
DAYS THAT BEGAN YESTERDAY...WITH OVER 2 INCHES. SHOWERS AND
THUNDERSTORMS WILL BECOME HEAVY DURING THE AFTERNOON WITH THE RISK
OF FLOODING BECOMING HIGH. MUDSLIDES ARE ALSO EXPECTED WHERE THIS
HAPPENS. A FLASH FLOOD WATCH IS IN EFFECT UNTIL 10 PM AST TONIGHT AND
MAY BE EXTENDED LATER TODAY. UPPER LEVEL DYNAMICS DID NOT APPEAR
TOO FAVORABLE EARLY TODAY BUT INCREASE CONSIDERABLY AFTER NOON
LOCAL TIME AND CONTINUE TO INCREASE THROUGH MIDNIGHT. IT IS
POSSIBLE THAT SHOWERS AND THUNDERSTORMS WILL NOT DIE OFF AS EARLY
THIS EVENING AS THEY DID ON SUNDAY AND THIS WILL INCREASE THE
POSSIBILITY OF LOCAL RIVER FLOODING AS WELL. STRONG DIVERGENCE
ALOFT CONTINUES THROUGH MUCH OF TUESDAY AND PRECIPITABLE WATER
REMAINS AROUND 2 INCHES THROUGH THE DAY. THIS WILL CONTINUE THE
THREAT OF FLOODING THROUGH TOMORROW. CONDITIONS BEGIN TO IMPROVE
WEDNESDAY AS THE UPPER LEVEL LOW FILLS AND BEGINS TO RETREAT TO
THE NORTH. AT THIS TIME THE GFS SHOWS THE AXIS OF THE RETREATING
UPPER LEVEL LOW CROSSING PUERTO RICO AND THE U.S. VIRGIN ISLANDS
ON THURSDAY NIGHT. ALTHOUGH THIS WILL MARK THE BEGINNING OF THE
DRIEST PERIOD OF THE NEXT 7 DAYS. MOISTURE RETURNS LATE
FRIDAY...AND CONTINUES SATURDAY AND SUNDAY BEFORE FALLING OFF
ABRUPTLY EARLY NEXT WEEK.

&&

.AVIATION...SHRA/TSRA WILL CONTINUE OVER THE FLYING AREA THRU THE
FORECAST PERIOD. PASSING SHOWERS CAN BE EXPECTED MAINLY ACROSS THE
TJPS...TIST...TISX...TNCM AND TKPK EARLY IN THE MORNING. AFT 26/17Z
SHRA/TSRA ARE EXPECTED TO INCREASE ALONG...SOUTH AND NORTH OF THE
CORDILLERA CENTRAL. AS A RESULT...BRIEF MVFR/IFR CONDS IN AND AROUND
TJSJ...TISX...TIST...TJBQ...TJMZ AND THE LEEWARD TERMINALS THRU AT
LEAST 26/23Z. SOUTHERLY WINDS AT 5 TO 10 KT WITH SEA BREEZE
VARIATIONS AFT 26/13Z WILL BE GUSTY IN AND NEAR TSRA.

&&

.MARINE...SEAS REMAIN RELATIVELY TRANQUIL THROUGH THURSDAY...WITH
EXCEPTION OF PERIODS OF NUMEROUS THUNDERSTORMS CARRYING TORRENTIAL
RAIN AND GUSTY WINDS. NORTH NORTHWEST SWELL OF UP TO 3 FEET WILL
BEGIN LATER THIS WEEK AND WIND WAVES WILL INCREASE AS LOCAL TRADE
WINDS RISE FROM GENTLE TO MODERATE.

&&

.HYDROLOGY...SOME AREAS OF EASTERN PUERTO RICO HAD UP TO 5 INCHES
OF RAIN ACCORDING TO DOPPLER RADAR CONFIRMED BY RAIN GAGES. SOME
AREAS OF WESTERN PUERTO RICO HAD AS MUCH AS 10 INCHES THOUGH NO
RAIN GAGES WERE PRESENT TO CONFIRM THESE AMOUNTS. THIS LEAVES
SOILS VERY SATURATED AND PRONE TO SLIPPAGE WHEN MORE HEAVY COMES
THIS AFTERNOON. ADDITIONALLY THE GUANAJIBO RIVER IS STILL JUST
OVER 20 FEET AND LEVELING OFF AFTER A VERY SLOW RISE. MORE
RAINFALL WILL DRIVE IT BACK INTO FLOOD STAGE THIS
AFTERNOON...MAKING FLOODING ALONG THIS RIVER MORE LIKELY. THIS MAY
ALSO BE TRUE OF THE MANATI. PERSONS WITH INTERESTS AROUND PUERTO
RICAN RIVERS SHOULD MAKE PREPARATIONS FOR HIGHER WATER LEVELS AND
REMAIN ALERT FOR RAPIDLY RISING WATER. RAINFALL AMOUNTS WILL BE
SIMILAR TO SUNDAY...BUT OVERALL RAINFALL WILL LIKELY BE HIGHER
THAN YESTERDAY...AND EXTREMES COULD BE MORE DRAMATIC WITH BETTER
DYNAMICS ALOFT TODAY THAN WERE SEEN YESTERDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 76 87 79 / 80 60 50 30
STT 87 78 89 78 / 60 60 70 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
330 PM AST MON OCT 26 2015

.SYNOPSIS...LONG WAVE TROUGH CONTINUE TO DOMINATE THE WEATHER
CONDITIONS. THIS UPPER TROUGH JUST NORTHWEST OF PUERTO RICO WILL
MAINTAIN VERY UNSTABLE ENVIRONMENT ACROSS PUERTO RICO AND THE
U.S. VIRGIN ISLANDS THROUGH AT LEAST ON TUESDAY. SURFACE TROUGH
NORTH OF THE AREA IS INDUCING A GENTLE SOUTHERLY FLOW ACROSS THE
ISLANDS...RESPONSIBLE FOR CARRYING ABUNDANT MOISTURE ACROSS THE
NORTHEAST CARIBBEAN REGION. WEATHER CONDITIONS IMPROVE SOMEWHAT BY
MIDWEEK AS EASTERLY TRADES RETURN TO THE AREA.

&&

.DISCUSSION...VERY MOIST AND UNSTABLE ENVIRONMENT CONTINUES TO
INDUCE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE
REGIONAL WATERS AND PORTIONS OF THE ISLANDS. CLOUDY SKIES PREVAILED
ACROSS MOST OF THE ISLANDS...EXCEPT THE WESTERN THIRD OF PUERTO
RICO WHERE PARTLY CLOUDY SKIES WERE OBSERVED TODAY. THIS ALLOW
TEMPERATURES TO RISE TO THE UPPER 80S OVER WESTERN PR...REACHING
THE CONVECTIVE TEMP ALLOWING SHOWERS AND THUNDERSTORMS TO DEVELOP
OVER THIS AREA. THE REST OF PUERTO RICO REMAINED FAIRLY STABLE AS
TEMPS DID NOT REACH THE CONVECTIVE TEMP OF 86 DEGREES...KEEPING
THE SHOWERS AND THUNDERSTORMS OVER WATERS.

DEEP TROPICAL MOISTURE WILL CONTINUE TO SURGE ACROSS THE LOCAL REGION
THROUGH AT LEAST TUESDAY. LOOKS LIKE THE REST OF TODAY AND TONIGHT
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL ADVECT OVER THE ISLANDS
FROM THE CARIBBEAN WATERS. HIGH POTENTIAL OF FLOODING RAINS CONTINUES
ACROSS PUERTO RICO AND THE U.S. VIRGIN ISLANDS THROUGH TUESDAY DUE
TO VERY UNSTABLE CONDITIONS ASSOCIATED WITH THE AFOREMENTIONED UPPER
LOW NORTHWEST OF THE REGION COMBINED WITH ABUNDANT MOISTURE AND
ALREADY SATURATED SOILS. THEREFORE...THE FLASH FLOOD WATCH HAS BEEN
EXTENDED THROUGH TUESDAY EVENING.

WEATHER CONDITIONS IMPROVE SOMEWHAT BY MIDWEEK WHEN DRIER AIR WILL
ADVECT AT MID LEVELS AND THE UPPER LEVEL TROUGH GRADUALLY FILLS.
AFTERNOON CONVECTION WILL THEN FOCUS OVER WESTERN PR AS EASTERLY
WINDS WILL RETURN TO THE AREA.

&&

.AVIATION...SHRA/TSRA WILL CONTINUE OVER THE FLYING AREA THRU THE
FORECAST PERIOD. PASSING SHOWERS CAN BE EXPECTED MAINLY ACROSS THE
TJPS...TIST...TISX...TNCM AND TKPK EARLY IN THE MORNING. AFT
26/17Z SHRA/TSRA ARE EXPECTED TO INCREASE ALONG...SOUTH AND NORTH
OF THE CORDILLERA CENTRAL. AS A RESULT...BRIEF MVFR/IFR CONDS IN
AND AROUND TJSJ...TISX...TIST...TJBQ...TJMZ AND THE LEEWARD
TERMINALS THRU AT LEAST 26/23Z. SOUTHERLY WINDS AT 5 TO 10 KT WITH
SEA BREEZE VARIATIONS AFT 26/13Z AND GUSTY IN AND NEAR TSRA.

&&

.MARINE...SEAS BETWEEN 2 TO 4 FEET WITH OCCASIONAL SEAS UP TO 5
FEET OVER THE NEXT FEW DAYS. ISOLATED BUT STRONG THUNDERSTORMS
WITH DANGEROUS LIGHTNING...WILL CONTINUE TO AFFECT PORTIONS OF THE
LOCAL WATERS AND PASSAGES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 87 79 89 / 60 50 30 40
STT 78 89 78 88 / 60 70 50 50

&&

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
540 AM AST TUE OCT 27 2015

.SYNOPSIS...THE AXIS OF A TUTT LOW WILL CROSS INTO PUERTO RICO ON
WEDNESDAY AND WEAKEN DURING THE WEEK. ANOTHER TROUGH WILL DIG INTO
THE DOMINICAN REPUBLIC OVER THE WEEKEND. A CUT-OFF LOW OUT OF THIS WILL
DEVELOP AND MOVE INTO THE WESTERN CARIBBEAN NEXT WEEK...LEAVING
WEAK FLOW OVER THE LOCAL AREA.

AT MID LEVELS...HIGH PRESSURE OVER THE SUB-TROPICAL ATLANTIC WILL
CONTINUE INTO EARLY NEXT WEEK. WEAK LOW PRESSURE NORTHWEST OF
PUERTO RICO WILL BE ABSORBED INTO THE WESTERLY FLOW NORTH OF THE
AREA LATER THIS WEEK. HIGH PRESSURE IN THE NORTHWEST CARIBBEAN
LATE THIS WEEK WILL MOVE NORTHEAST AND BECOME THE DOMINANT HIGH OF
THE AREA.

AT LOWER LEVELS...HIGH PRESSURE OVER THE NEW ENGLAND STATES WILL
MOVE INTO THE CENTRAL ATLANTIC OCEAN BY FRIDAY. LOW PRESSURE
CONTINUES IN THE SOUTHWEST CARIBBEAN DRIVING GENTLE TO MODERATE
EAST SOUTHEAST TRADE WINDS. SOME WEAK TROUGHINESS FROM MID AND
UPPER LEVELS WILL INFLUENCE THE SURFACE FLOW FOR MUCH OF THE
PERIOD. BANDS OF MOISTURE WILL TRAVEL WITH THE TRADE WIND FLOW
BRINGING SCATTERED SHOWERS ONCE MOISTURE BROUGHT UP BY THE
SOUTHERLY FLOW WE HAVE RECENTLY EXPERIENCED HAS MOVED ON.

&&

.DISCUSSION...SHOWER AND THUNDERSTORMS SKIRTED THE LOCAL ISLANDS
MUCH OF YESTERDAY AND OVERNIGHT LAST NIGHT BECAUSE HEAVY CLOUD
COVER LEFT THE OCEANS WARMER THAN LAND AREAS MUCH OF THE TIME. A
WEAK LOW PRESSURE DEVELOPING SOUTH SOUTHWEST OF PUERTO RICO WAS
BRINGING MOISTURE UP ACROSS THE FORECAST AREA AND ISOLATED HEAVY
SHOWERS WITH EMBEDDED THUNDERSTORMS WERE FORMING IN A BROADER AREA
OF LIGHT TO MODERATE RAIN. LIGHT WINDS HAVE CONTINUED AND THESE
BEING MAINLY DRIVEN BY LAND BREEZES OVERNIGHT.

THE BAND OF MOISTURE MOVING UP THROUGH THE AREA IS EXPECTED TO
CONTINUE WITH PRECIPITABLE WATER VALUES BEING EVEN HIGHER THAN
YESTERDAY. BECAUSE OF THE LOW PRESSURE AND SOME BUT LIMITED
CONVECTION TO THE SOUTH SOUTHWEST...HEAVY CLOUD MID AND HIGH LEVEL COVER
WILL CONTINUE OVER THE LOCAL AREA INHIBITING MOST STRONG
CONVECTION OVER LAND. BETTER INSTABILITY AND WARM OCEAN
WATERS...HOWEVER...WILL ALLOW SHOWERS AND THUNDERSTORMS TO FAVOR
THE SURROUNDING WATERS MUCH AS THEY DID YESTERDAY.

WE HAVE ELECTED TO CONTINUE THE FLASH FLOOD WATCH FOR PUERTO RICO
AND THE U.S. VIRGIN ISLANDS MAINLY BECAUSE OF THE UNCERTAINTY OF
STRONG SHOWER AND THUNDERSTORM DEVELOPMENT OVER THE INTERIOR OF
PUERTO RICO AND BANDING ACROSS THE U.S. VIRGIN ISLANDS. BECAUSE
CONVECTION IS BEING LIMITED BY THE HEAVY MID AND UPPER LEVEL
CLOUDINESS...HOWEVER...IT IS EXPECTED...AT THIS TIME...THAT
PRECIPITATION OVER LAND SHOULD BE LIGHT TO MODERATE OVER ALL
AREAS. SHOULD CLOUDS BREAK...THE THUNDERSTORMS THAT WOULD FORM
WOULD VIGOROUSLY FEED OFF OF THE ABUNDANT MOISTURE AND...MOVING
SLOWLY...WOULD BE ABLE TO PRODUCE MORE RAINFALL THAN SATURATED
SOILS COULD ABSORB AND RIVERS ALREADY RUNNING HIGHER THAN NORMAL
COULD CARRY AWAY.

ON WEDNESDAY...AS THE LOW PRESSURE CROSSES THE AREA AND
DISSIPATES...SOME OF THIS CLOUD COVER WILL NOT BE GENERATED AND
NORMAL LOW LEVEL CONVERGENCE WILL BE ABLE TO FORM SHOWERS AND
THUNDERSTORMS IN WESTERN PUERTO RICO AND OVER HIGHER TERRAIN THAT
ARE LIKELY TO GENERATE BETTER SHOWER AND THUNDERSTORM ACTIVITY
THERE. ALSO AS WINDS STRENGTHEN SOMEWHAT LATER THIS WEEK AND INTO
THE WEEKEND...THE EARLY MORNING SHOWERS THAT DAMPEN THE EASTERN
SLOPES OF PUERTO RICO WILL BE ABLE TO RETURN.

&&

.AVIATION...VCSH WITH LAYERS OF MID AND HIGH CLOUDS ARE EXPECTED
TO CONTINUE THRU THE FORECAST PERIOD. PASSING SHRA CAN BE
EXPECTED MAINLY ACROSS THE TJPS...TIST... TISX...TNCM AND TKPK
EARLY IN THE MORNING. AFT 27/17Z...SHRA/TSRA ARE EXPECTED TO
DEVELOP ALONG... SOUTH AND NORTH OF THE CORDILLERA CENTRAL
BRINGING BRIEF MVFR CONDS AND MOUNTAIN OBSCURATIONS IN AND AROUND
TJSJ...TISX...TIST ...TJBQ...TJMZ AND THE LEEWARD TERMINALS THRU
AT LEAST 27/23Z. EASTERLY WINDS AT 5 TO 10 KT WITH SEA BREEZE
VARIATIONS AFT 27/13Z AND GUSTY IN/NEAR SHRA/TSRA.

&&

.MARINE...SEAS REMAIN RELATIVELY TRANQUIL AND GENERALLY BELOW 5
FEET UNTIL LATER THIS WEEK WHEN A 2 TO 4 FOOT SWELL FROM THE NORTH
ENTERS THE AREA. PRESENTLY SMALL CRAFT ADVISORIES ARE NOT EXPECTED
DURING THE NEXT 5 TO 7 DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 78 87 79 / 70 60 60 40
STT 84 78 86 79 / 60 70 70 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
323 PM AST TUE OCT 27 2015

.SYNOPSIS...LONG WAVE LOW/TUTT CONTINUE TO DOMINATE THE WEATHER
CONDITIONS. THIS UPPER TROUGH JUST NORTHWEST OF PUERTO RICO WILL
MAINTAIN VERY UNSTABLE ENVIRONMENT ACROSS PUERTO RICO AND THE U.S.
VIRGIN ISLANDS THROUGH AT LEAST TONIGHT. SURFACE TROUGH NORTH OF
THE AREA IS INDUCING A GENTLE SOUTHERLY FLOW ACROSS THE ISLANDS...
RESPONSIBLE FOR CARRYING ABUNDANT MOISTURE ACROSS THE NORTHEAST
CARIBBEAN REGION. WEATHER CONDITIONS IMPROVE SOMEWHAT THROUGH THE
END OF THE WEEK AS EASTERLY TRADES RETURN TO THE AREA.

&&

.DISCUSSION...MUCH LESS CLOUDINESS COMPARED TO YESTERDAY ALLOW
TEMPS TO REACH THE MID-UPPER 80S. THIS DIURNAL HEATING COMBINED
WITH VERY MOIST AND UNSTABLE ENVIRONMENT INDUCED THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS ACROSS THE NORTHERN HALF OF PUERTO
RICO AS WELL AS PORTIONS OF THE REGIONAL WATERS. SHOWERS WITH
HEAVY RAINFALL ALSO DEVELOPED THIS MORNING ACROSS PORTIONS OF
THE VIRGIN ISLANDS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP OVER THE WEST PORTIONS OF PUERTO RICO UNTIL
SUNSET.

WEATHER CONDITIONS IMPROVE SOMEWHAT THE REST OF THE WHEN DRIER
AIR WILL ADVECT AT MID LEVELS. ALTHOUGH...NO WIDESPREAD RAINFALL
IS EXPECTED OVER THE NEXT SEVERAL DAYS...DEEP LAYER INSTABILITY
AND DECENT MOISTURE CONTENT WILL COMBINE TO PRODUCE ACTIVE
AFTERNOONS ACROSS THE WEST INTERIOR AND WEST PORTIONS OF PUERTO
RICO EACH AFTERNOON. OVERALL...THE POTENTIAL FOR LOCALLY HEAVY
RAINS CONTINUES THROUGH THE END OF THE WEEK...BUT IT WILL BE
LOCALIZED OVER THE INTERIOR AND WESTERN HALF OF PUERTO RICO.

&&

.AVIATION...PERIODS OF MVFR OR EVEN IFR CONDITIONS AND MOUNTAIN
OBSCURATIONS EXPECTED AT JSJ/JMZ AND JBQ IN SHRA/TSRA THROUGH
27/23Z. ELSEWHERE MOSTLY VFR WITH VICINITY SHRA/TSRA. EASTERLY
WINDS AT 10 KNOTS OR LESS WITH SEA BREEZE VARIATION...BECOMING
LIGHT AND VARIABLE AFTER 27/23Z.

&&

.MARINE...A SHORT-PERIOD NORTHERLY SWELL OF 3-4 FEET IS REACHING
THE LOCAL AREA TODAY. MARINE CONDS WILL NOT CHANGE MUCH WITH SEAS
3-5 FEET OVER THE NEXT SEVERAL DAYS. PRESENTLY SMALL CRAFT ADVISORIES
ARE NOT EXPECTED DURING THE NEXT 5 TO 7 DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 87 79 87 / 60 60 40 40
STT 78 86 79 86 / 70 70 40 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
552 AM AST WED OCT 28 2015

.SYNOPSIS...
AN UPPER LEVEL TROUGH AND THE CUT OF LOW ASSOCIATED WITH IT WILL
CONTINUE TO DOMINATE THE LOCAL WEATHER CONDITIONS. AN INDUCE
SURFACE TROUGH WILL MOVE ACROSS THE REGION TODAY. WEATHER
CONDITIONS ARE EXPECTED TO IMPROVE SOMEWHAT THROUGH THE END OF
THE WEEK AS EASTERLY TRADES RETURN TO THE AREA.

&&

.DISCUSSION...
THE MID-UPPER LEVEL CLOUD LAYER DISSIPATED OR MOVED AWAY FROM THE
REGION OVERNIGHT. SHOWER ACTIVITY INCREASED EARLY IN THE MORNING
AS AN INDUCED TROUGH MOVED OVER THE REGION. AS A RESULT...SHOWERS
ARE EXPECTED TO CONTINUE ACROSS THE WINDWARD SECTIONS DURING THE
MORNING HOURS. IN ADDITION...EXPECT COASTAL MAXIMUM TEMPERATURES
IN THE UPPER 80S TO LOW 90S. DURING THE AFTERNOON HOURS...THE
DIURNAL HEATING COMBINED WITH ABOVE NORMAL TPW AND DEEP LAYER
INSTABILITY WILL ENHANCE AFTERNOON CONVECTION ALONG AND TO THE
WEST OF THE MOUNTAIN RANGE OF PUERTO RICO AND DOWNSTREAM FROM
THE US VIRGIN ISLANDS. IN GENERAL...THE LIKELIHOOD FOR LOCALLY
HEAVY RAINS CONTINUES THROUGH THE END OF THE WEEK...BUT IT WILL BE
LOCALIZED OVER THE INTERIOR AND WESTERN HALF OF PUERTO RICO DURING
THE AFTERNOON WITH PASSING SHOWERS ACROSS THE WINDWARD SECTIONS
DURING THE OVERNIGHT AND EARLY MORNING HOURS.

&&

.AVIATION...MAINLY VFR CONDITIONS ARE EXPECTED OVER ALL TAF SITES
THROUGH 28/17Z. VCSH TJSJ...TNCM...TKPK...AND TIST. AFT 28/17Z
SHRA/TSRA DEVELOPING OVER INTERIOR AND WRN PR WITH MVFR/IFR CONDS
AND MTN OBSCURATIONS. BRIEF MVFR AT TJMZ...TJBQ. LOW LEVEL WINDS
WILL BE MAINLY LIGHT AND VARIABLE...BECOMING EAST SOUTHEAST UP TO
15 KTS BTWN 28/13-15Z EXCEPT FOR SEA BREEZE VARIATIONS.

&&

.MARINE...THE LOCAL BUOY NETWORK INDICATED A SHORT PERIOD NORTH
SWELL OF 3-4 FEET AND WINDS OF 15 KNOTS OR LESS. ANOTHER MODERATE
NE SWELL IS EXPECTED TO REACH THE LOCAL AREA BY FRIDAY INTO THE
WEEKEND. MARINE CONDS WILL NOT CHANGE MUCH WITH SEAS 2-4 FEET WITH
OCCASIONAL SEAS UP TO 5 FEET AT LEAST UNTIL FRIDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 89 77 / 40 40 40 20
STT 87 77 88 78 / 40 50 50 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
301 PM AST WED OCT 28 2015

.SYNOPSIS...AN ELONGATED UPPER TROUGH EXTENDS SOUTHWARDS FROM THE
SOUTHWEST ATLANTIC ACROSS PUERTO RICO AND INTO THE EASTERN CARIBBEAN
PUERTO RICO. THIS UPPER TROUGH WILL CONTINUE PROVIDE GOOD VENTILATION
AND SUPPORT FAIR AMOUNTS OF CONVECTION OVER THE ISLANDS TODAY.INDUCED
LOW LEVEL TROUGH EXTENDS ACROSS THE REGION AND WILL CONTINUE SHIFTING
WEST THROUGH EARLY THURSDAY. LIGHT EASTERLY TRADE WINDS WILL THEREFORE
PREVAIL EXCEPT FOR LOCAL SEA BREEZE VARIATIONS.

&&

.DISCUSSION...CONTINUED FAVORABLE CONDITIONS FOR AFTERNOON AND EARLY
EVENING CONVECTION ACROSS THE ISLANDS DURING THE REST OF THE DAY.
HOWEVER EXPECT THE ACTIVITY ACROSS PUERTO RICO TO BE FOCUSED ACROSS
THE INTERIOR...CENTRAL AND WEST SECTIONS OF PUERTO RICO DURING THE
REST OF THE AFTERNOON. HOWEVER THE PREVAILING SOUTHEASTERLY WIND
FLOW WILL TRANSPORT PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS PORTIONS OF THE SAN JUAN METRO AREA. PERIODS OF MODER ATE
TO LOCALLY HEAVY RAINFALL CAN AGAIN BE EXPECTED IN ISOLATED AREAS...
SOME OF ACTIVITY WILL LEAD TO URBAN AND SMALL STREAM FLOODING...AS
SOIL REMAIN SATURATED AND RIVERS AND STREAMS REMAIN AT ABOVE
NORMAL LEVELS.

GFS MODEL GUIDANCE WHICH INITIALIZED WELL SUGGESTS A GRADUAL DECREASE
IN MOISTURE ADVECTION ON THURSDAY AND FRIDAY...AS THE INDUCED LOW LEVEL
TROUGH MOVES FARTHER WEST OF THE REGION...AND WEAKENS AS HIGH PRESSURE
BUILDS NORTH OF THE AREA. THIS WILL ALLOWING FOR MODERATE EASTERLY WINDS.
ON FRIDAY EVEN DRIER CONDITIONS EXPECTED AS THE RIDGE BUILDS ALOFT.
THIS WILL ALSO SUPPORTED BY SURFACE RIDGE BUILDING NORTH OF THE REGION.

HOWEVER...OVER THE UPCOMING WEEKEND ALL MODELS SUGGEST A PATTERN
SHIFT ONCE AGAIN BY SUNDAY AND INTO THE EARLY PART OF NEXT WEEK
WITH INCREASING MOISTURE ADVECTION AND UPPER LEVEL INSTABILITY. A
DEEP LAYER POLAR TROUGH BECOMES AMPLIFIED ACROSS THE REGION. THIS
WILL BE SUPPORTED BY AN INDUCED SURFACE TROUGH WHICH IS FORECAST
TO SET UP ONCE AGAIN OVER THE AREA. UNDER THIS SCENARIO...THE
FORECAST AREA WILL ONCE AGAIN BE IN A VERY MOIST AND UNSTABLE
ENVIRONMENT. AS USUAL THIS IS STILL A SEVERAL DAYS OUT SO WILL
STAY CONSERVATIVE AND CONTINUE TO MONITOR AND SEE HOW THE MODELS
ADJUST AND THE EXPECTED PATTERN UNFOLDS. IN THE MEANTIME THE SOIL
ACROSS THE ISLANDS REMAIN FAIRLY SATURATED AND UNSTABLE AND ANY
ADDITIONAL RAINFALL OVER THE NEXT FEW DAYS WILL LEAD TO MINOR
URBAN AND SMALL STREAM FLOODING IN ISOLATED AREA. STAY TUNED...

&&

.AVIATION...VCSH TJSJ...TNCM...TKPK...AND TIST. UNTIL 28/22Z SHRA/TSRA
DEVELOPING OVER INTERIOR AND NRN HALF OR PR WITH MVFR/IFR CONDS AND
MTN TOP OBSCR...WITH BRIEF MVFR AT TJMZ...TJBQ. LOW LEVEL WINDS WILL
BE MAINLY LIGHT AND VARIABLE...BECOMING EAST SOUTHEAST UP TO 15 KTS
BTW 28/13-15Z EXCEPT FOR SEA BREEZE VARIATIONS.

&&

.MARINE...THE LOCAL BUOYS SUGGEST SUBSIDING NE SWELL OF 3-4 FEET WITH
WINDS OF 15 KNOTS OR LESS. ANOTHER MODERATE NE SWELL IS EXPECTED TO
REACH THE LOCAL AREA BY FRIDAY INTO THE WEEKEND.THEREFORE MARINE CONDS
NOT FORECAST TO CHANGE SEAS 2-4 FEET AND OCCASIONAL SEAS UP TO 5 FEET
AT LEAST UNTIL FRIDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 89 78 89 / 30 30 20 20
STT 78 88 78 89 / 50 50 30 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
611 AM AST THU OCT 29 2015

.SYNOPSIS...AN UPPER LEVEL TROUGH WILL CONTINUE OVER THE REGION.
AS AN UPPER LEVEL RIDGE INTENSIFY OVER THE WESTERN CARIBBEAN THE
UPPER LEVEL TROUGH IS EXPECTED TO WEAKEN. ANOTHER TROUGH ALOFT
WILL AMPLIFY FROM THE ATLANTIC OCEAN OVER THE REGION BY SUNDAY
AND INTO THE UPCOMING WEEK. A SURFACE PERTURBATION WILL CONTINUE
TO MOVE ACROSS THE REGION TODAY. A SURFACE HIGH PRESSURE IS
EXPECTED TO BUILD OVER THE NORTH CENTRAL ATLANTIC TO SUPPORT THE
RETURN OF THE EASTERLY TRADES ACROSS THE REGION.

&&

.DISCUSSION...THE COMBINATION OF THE AVAILABLE LOW LEVEL MOISTURE
AND A SURFACE TROUGH PRODUCED SHOWERS...MAINLY OVER THE LOCAL
WATERS...AND SOME OF THEM AFFECTED THE WINDWARD SECTIONS OF
PUERTO RICO AND THE U.S. VIRGIN ISLANDS. HOWEVER...RAINFALL
ACCUMULATIONS HAVE BEEN LESS THAN A QUARTER OF AN INCH. DURING THE
MORNING HOURS...EXPECT PASSING SHOWERS...MAINLY ACROSS THE
COASTAL WINDWARD AREAS OF PUERTO RICO AND THE U.S. VIRGIN
ISLANDS.

THE TROUGH ALOFT WILL CONTINUE TO SUPPORT THE DEVELOPMENT OF
AFTERNOON CONVECTION MAINLY TO THE WEST AND OVER THE CENTRAL
MOUNTAIN RANGE AND THE LUQUILLO RANGE...AS WELL AS DOWNSTREAM
FROM THE U.S. VIRGIN ISLANDS.

GFS IS STILL SUGGESTING THE WEAKENING OF THE TROUGH ALOFT DURING
THE WEEKEND. HOWEVER...THE AVAILABLE LOW LEVEL MOISTURE COMBINED
WITH THE LOCAL EFFECTS WILL SUPPORT THE FORMATION OF AFTERNOON
SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR AND WESTERN
SECTIONS...FOLLOWED BY OVERNIGHT AND EARLY MORNING SHOWERS EACH
DAY DURING WEEKEND ON THE EASTERN COAST OF PR AND AROUND THE U.S.
VIRGIN ISLANDS. ANOTHER UPPER LEVEL TROUGH IS EXPECTED TO AMPLIFY
OVER THE REGION INCREASING MOISTURE ADVECTION AND UPPER LEVEL
INSTABILITY. AS A RESULT...ENVIRONMENTAL CONDITIONS WILL BE VERY
MOIST AND UNSTABLE FOR THE FIRST PART OF NEXT WEEK.

&&

.AVIATION...VFR CONDS WILL PREVAIL AT ALL TAF SITES...EXCEPT OVER PR
AFT 29/16Z...SHRA/TSRA DVLPG INTERIOR AND WRN PORTIONS TO BRING
MVFR/IFR CONDS AND MTN OBSCURATIONS IN HEAVY RAIN WITH PDS OF MVFR
AT TJMZ. CONDS IMPVG AFT 29/22Z. WINDS ALF E 5 TO 10 KT UP TO FL100
THEN VRB 10 KT OR LESS TO FL450.

&&

.MARINE...THE LOCAL BUOYS INDICATED SEAS AT 2 TO 4 FEET WITH
WINDS OF 15 KNOTS OR LESS. FOR TODAY...EXPECT SEAS OF 5 FEET OR
LESS AND WINDS BELOW 15 KNOTS. IN ADDITION...THE SOUTH BERMUDA
BUOY STATION... 41049...OBSERVED A MODERATE NNE SWELL AT 8
FT...11 SECONDS. THAT SWELL WILL REACH THE LOCAL AREA PRODUCING
WAVE HEIGHTS BETWEEN 4 AND 5 FEET WITH OCCASIONAL SEAS UP TO 6
FT BY FRIDAY INTO THE WEEKEND. PLEASE...STAY TUNED FOR MORE
DETAILS ABOUT THE EVOLUTION OF THIS SWELL.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 89 77 / 40 30 20 20
STT 87 78 88 79 / 40 50 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
331 PM AST THU OCT 29 2015

.SYNOPSIS...AN UPPER LEVEL TROUGH WILL CONTINUE TO WEAKEN OVER
THE REGION...WHILE AS AN UPPER LEVEL RIDGE WILL BUILD OVER THE
WESTERN CARIBBEAN AND SOUTHWEST ATLANTIC OVER THE NEXT FEW DAYS.
THIS WILL HELP TO ESTABLISH MODERATE SUBSIDENCE ACROSS THE REGION
ON FRIDAY AND SATURDAY. HOWEVER ANOTHER TROUGH ALOFT WILL AMPLIFY
FROM THE ATLANTIC OCEAN OVER THE REGION BY SUNDAY AND INTO THE UPCOMING
WEEK. WEAKENING SURFACE TROUGH WILL CONTINUE TO SHIFT FARTHER WEST
OF THE REGION OVERNIGHT THROUGH FRIDAY...AS SURFACE HIGH PRESSURE
RIDGE BUILDS OVER THE NORTH CENTRAL ATLANTIC. THIS WILL SUPPORT
EASTERLY TRADE WINDS ACROSS THE FORECAST AREA.

&&

.DISCUSSION...AVAILABLE MOISTURE COMBINED WITH DIURNAL HEATING
AND LOCAL EFFECTS AND LEAD TO SHOWERS AND THUNDERSTORM DEVELOPMENT
ACROSS PORTIONS OF THE CENTRAL INTERIOR AND THE SOUTHERN SLOPES OF
PUERTO RICO. THE HEAVIEST SHOWERS AND THUNDERSTORM ACTIVITY OCCURRED
ACROSS THE INTERIOR SECTIONS AND SOME AREAS OF THE SOUTHERN SLOPES.
SOME AREAS PRODUCED PERIODS OF LOCALLY HEAVY RAINFALL WHICH LEAD
TO MINOR URBAN AND SMALL STREAM FLOODING.

FOR FRIDAY AND INTO SATURDAY...ALTHOUGH A DECREASE IN MOISTURE
ADVECTION AND UNFAVORABLE DYNAMICS IS FORECAST...STILL EXPECT THE
COMBINATION OF AVAILABLE MOISTURE WITH LOCAL AND DIURNAL EFFECTS
TO SUPPORT AFTERNOON CONVECTION MAINLY ACROSS PARTS OF THE INTERIOR
AND WEST SECTION OF PUERTO RICO. ONLY ISOLATED AFTERNOON SHOWERS
EXPECTED OVER THE REST OF THE ISLANDS.

FOR THE LATTER PART OF THE WEEKEND...ALL MODEL MODEL GUIDANCE
STILL SUGGEST THE AMPLIFICATION OF MID TO UPPER LEVEL TROUGH OVER
THE AREA ONCE AGAIN...WITH ANOTHER INDUCED LOW LEVEL TROUGH EXPECTED
TO SET UP OVER THE NORTHEASTERN CARIBBEAN. IN ADDITION THE ARRIVAL
OF A TROPICAL WAVE LATE SATURDAY THROUGH SUNDAY ACROSS THE EASTERN
CARIBBEAN...WILL BRING A WETTER WEATHER PATTERN BY SUNDAY AND INTO
THE EARLY PART OF NEXT WEEK DUE TO INCREASING MOISTURE ADVECTION
AND UPPER LEVEL INSTABILITY. BASED ON LATEST MODEL GUIDANCE...
ENVIRONMENTAL CONDITIONS ARE THEN EXPECTED TO REMAIN VERY MOIST
AND UNSTABLE FROM THEN ON AND AT LEAST UNTIL THE MIDDLE OF NEXT
WEEK. STAY TUNED.

&&

.AVIATION...SHRA/TSRA EXPECTED ACROSS PR THROUGH 29/23Z...WITH VCTS
EXPECTED AT TJPS/TJMZ/TJBQ THROUGH 29/23Z. E-ESE WINDS TO CONTINUE
WITH SEA BREEZE VARIATIONS AT AROUND 10 KNOTS...WINDS DECREASING
SLIGHTLY OVERNIGHT...BECOMING LIGHT AND VARIABLE FOR THE TERMINALS
IN PUERTO RICO...LIGHT AND EASTERLY ACROSS THE USVI...TKPK AND TNCM.
ISOLD/SCT -SHRA ACROSS THE AREA OVERNIGHT MAY CAUSE VCSH ACROSS MOST
OF THE LOCAL TERMINALS.


&&

.MARINE...SEAS BETWEEN 2 TO 5 FEET AND WINDS BELOW 15 KNOTS EXPECTED
TO CONTINUE OVERNIGHT THROUGH FRIDAY. IN ADDITION...THE SOUTH BERMUDA
BUOY STATION... 41049...CONTINUED TO SUGGEST A MODERATE NNE SWELL
OF 8 FT AT AROUND 11 SECONDS. THAT SWELL SHOULD ARRIVE ACROSS THE
LOCAL ATLANTIC WATERS PRODUCING WAVE HEIGHTS BETWEEN 4 AND 5 FEET
WITH OCCASIONAL SEAS UP TO 6 FT BY FRIDAY AND INTO THE WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 89 77 90 / 30 20 20 30
STT 78 88 79 89 / 50 20 20 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
546 AM AST FRI OCT 30 2015

.SYNOPSIS...AT UPPER LEVELS...A WEAK LOW JUST SOUTH OF PUERTO RICO
WILL FADE AND A WEAK HIGH WILL RIDGE EAST OVER THE AREA TONIGHT
AHEAD OF A STRONGER LOW DIGGING SOUTHWEST ACROSS THE MONA CHANNEL
SATURDAY NIGHT. BY SUNDAY EVENING THIS LOW WILL HAVE DUG INTO THE
DOMINICAN REPUBLIC SENDING SOUTHERLY FLOW AND SOME DIVERGENCE OVER
THE AREA. THE LOW WILL THEN MOVE WEST SOUTHWEST AND AWAY FROM THE
AREA. HIGH PRESSURE WILL RIDGE IN FROM THE SOUTH TUESDAY NIGHT. A
WEAK TROUGH JUST TO THE NORTH OF THE AREA WILL BRING A MODEST JET
OVER THE AREA BY THE END OF NEXT WEEK.

AT MID LEVELS...HIGH PRESSURE EXTENDING FROM THE YUCATAN PENINSULA
TO THE ATLANTIC WILL BECOME DIVIDED BY A TROUGH EXTENDING SOUTH
ACROSS THE EASTERN TIP OF THE DOMINICAN REPUBLIC SATURDAY NIGHT
AND A POCKET OF COLD AIR WILL PASS TO THE NORTHWEST SUNDAY
MORNING. THE TROUGH WILL MOVE WEST AND BECOME A LOW PRESSURE OVER
THE WESTERN CARIBBEAN BY MONDAY NIGHT WHILE HIGH PRESSURE
CONTINUES NORTH OF THE AREA. HIGH PRESSURE WILL RECEDE INTO THE
SOUTHWESTERN UNITED STATES LATER NEXT WEEK. MID LEVELS ARE DRIER
SATURDAY...AND WEDNESDAY THROUGH THE FOLLOWING SATURDAY. BEST
MOISTURE AT MID LEVELS WILL BE SUNDAY THROUGH TUESDAY AFTERNOONS
AND THE FOLLOWING SUNDAY.

AT LOWER LEVELS...HIGH PRESSURE WILL BUILD NORTH OF THE AREA AND
EASTERLY TRADE WINDS WILL INCREASE TODAY THROUGH NEXT FRIDAY. WEAK
WAVES MOVE THROUGH THE AREA SATURDAY MORNING...SUNDAY AND MONDAY
NIGHT. MOISTURE FROM THE SOUTHEAST MOVES OVER THE AREA LATE IN THE
FIRST WEEK OF NOVEMBER.

&&

.DISCUSSION...EASTERLY TRADE WINDS CONTINUED TO CARRY MANY SMALL
SHOWERS ACROSS THE LOCAL WATERS. A FEW MOVED INTO EASTERN PUERTO
RICO AS FAR AS SAN LORENZO WITH VERY MINOR ACCUMULATIONS. THE
WATERS AROUND THE U.S. VIRGIN ISLANDS HAD ALMOST NO SHOWERS.
PRECIPITABLE WATER IS DIMINISHING NOW...BUT WILL REBOUND BEGINNING
LATE TONIGHT. ALTHOUGH SHOWERS AND THUNDERSTORMS MAY BE SLIGHTLY
LESS VIGOROUS AND WIDESPREAD TODAY AND SATURDAY...THEY STILL
POSSESS THE POTENTIAL FOR VERY LOCALIZED URBAN AND SMALL STREAM
FLOODING IN WESTERN PUERTO RICO WITH SOME RAPID RISES ON MAINSTEM
RIVERS.

AFTER TODAY EACH AFTERNOON DIURNAL PEAK OF PRECIPITABLE WATER
WILL BECOME SLIGHTLY LARGER THROUGH TUESDAY. THE LOW PRESSURE
DIVING INTO THE DOMINICAN REPUBLIC WILL CARRY A COLD POCKET OF AIR
AT MID AND UPPER LEVEL THAT WILL PASS BY CLOSEST ON SUNDAY
MORNING. THIS WILL PULL THE LIFTED INDEX DOWN AS LOW AS MINUS 8
SUNDAY MORNING INTO EARLY AFTERNOON. THIS INSTABILITY AND THE
INCREASED MOISTURE SHOULD BOOST SHOWER AND THUNDERSTORM
PRODUCTIVITY CONSIDERABLY SUNDAY AND WOULD EXPECT MUCH MORE
LIGHTNING WITH GREATER POTENTIAL FOR URBAN AND SMALL STREAM
FLOODING WITH RAPID RIVER RISES. INCREASING SURFACE WINDS WILL
HELP SOME BY MOVING CELLS THROUGH A LITTLE MORE QUICKLY.
INSTABILITY DIMINISHES THROUGH FRIDAY BUT MOISTURE CONTINUES
THROUGH AT LEAST TUESDAY...SO SHOWERS AND THUNDERSTORMS WILL
CONTINUE DURING THE FIRST HALF OF NEXT WEEK...JUST NOT AS
STRONGLY. WOULD EXPECT THE BEST RAIN CHANCES AND AMOUNTS DURING
THIS PERIOD TO BE OVER WESTERN PUERTO RICO OVER BOTH THE NORTH AND
SOUTH HALVES SUNDAY...TAPERING OFF MONDAY THROUGH WEDNESDAY.
SHOWERS AND THUNDERSTORMS WILL LIKELY CONTINUE THROUGH THE REST OF
THE WEEK. MOISTURE COMING UP FROM THE SOUTHEAST THE SUNDAY AFTER
NEXT WILL ALSO INCREASE SHOWER ACTIVITY.


&&

.AVIATION...VFR CONDS WILL PREVAIL AT ALL TAF SITES...EXCEPT OVER
WEST PR BTWN 20/17Z-21Z. SHRA/TSRA DVLPG INTERIOR AND WRN PORTIONS
WILL LIKELY BRING TEMPO MVFR/IFR CONDS WITH MTN OBSCURATIONS IN
AND AROUND TJMZ AND POSSIBLY TJBQ. EASTERLY WINDS AROUND 10 KT
WILL PREVAIL BLW FL250.

&&

.MARINE...A NORTHERLY SWELL WILL CAUSE SEAS IN THE ATLANTIC AND
PASSAGES TO INCREASE TO 4 TO 6 FEET. OTHERWISE CONDITIONS WILL BE
BORDERLINE TRANQUIL. WINDS WILL INCREASE DURING THE UPCOMING WEEK
AND THE HIGHEST SEAS WILL OCCUR WEDNESDAY OR THURSDAY IN BOTH THE
ATLANTIC AND CARIBBEAN WATERS. SEAS SHOULD REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA THROUGH THE NEXT TEN DAYS. RIP CURRENT
RISK WAS HIGH ACROSS THE NORTHERN ATLANTIC COASTS AND SHOULD
CONTINUE AT LEAST THROUGH SATURDAY.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 90 78 / 20 30 30 60
STT 88 79 89 79 / 20 30 20 50