Area Forecast Discussion
Issued by NWS San Juan, PR

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000
FXCA62 TJSJ 020243 CCA
AFDSJU

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
1042 PM AST FRI AUG 1 2014

...TROPICAL STORM BERTHA CONTINUES TO MOVE WEST NORTHWEST AT MORE
THAN 20 MPH...

.UPDATE...A STREAMER OFF OF SAINT THOMAS AMPLIFIED AS IT
APPROACHED THE NORTHERN COAST OF PUERTO RICO LEAVING SOME RAIN
JUST NORTH OF THE AIRPORT. OTHERWISE SUBSIDENCE AHEAD OF TS BERTHA
HAS LIMITED CONVECTIVE ACTIVITY CONSIDERABLY. LATEST SOUNDING AT
02/00Z SHOWED WARMING AT 800 MB AND A 2000 FOOT ISOTHERMAL LAYER.
THIS WILL CONTINUE TO LIMIT INTENSIFICATION OF BERTHA AS IT MOVES QUICKLY
INTO THE LOCAL ENVIRONMENT OVERNIGHT.

&&

.AVIATION...THE PROXIMITY OF TROPICAL STORM BERTHA WILL CONTINUE TO
IMPACT TNCM AND TKPK DURING THE REST OF THE OVERNIGHT HOURS AND
THE REST OF THE TERMINALS BY EARLY SATURDAY MORNING.
THEREFORE...MVFR CONDS WITH PERIODS OF BRIEF IFR ARE EXPECTED
THROUGH THE END OF THE FCST PERIOD. SOME MVFR AND MTN OBSCURATIONS
ARE EXPECTED TO BEGIN AFT 02/05Z OVER TISX AND AFT 02/08Z TIST AND
TJSJ...BUT CONDITIONS ARE MOSTLY VFR EVEN IN THE LEEWARD ISLANDS.

&&

.MARINE...SEAS WILL BE ALMOST ENTIRELY DEPENDENT ON THE STRENGTH
AND POSITION OF BERTHA. MARINE GRIDS HAVE BEEN UPDATED FOR THE
LAST COASTAL WATERS FORECAST.

&&

.FIRE WEATHER...THE RED FLAG WARNING FOR SAINT CROIX HAS EXPIRED
AND IT IS NOT EXPECTED TO BE RENEWED TOMORROW DUE TO RAIN AND
HIGHER HUMIDITY.

&&

.PREV DISCUSSION... /ISSUED 741 PM AST FRI AUG 1 2014/

UPDATE...HAVE REVIEWED AND UPDATED MOST WINDS...POPS AND TEMPS
THROUGH AT LEAST SUNDAY. SOME WARMER MAX TEMPS IN LINE WITH
GUIDANCE MAY BE NOTED. ALSO EXPECT RAINS OTHER THAN A FEW SHOWERS
TO HOLD OFF UNTIL AFTER 6 AM AST FOR EASTERN PUERTO RICO.

DISCUSSION...NHC CONTINUES TO MENTION DRY AIR AND SHEAR WITH
REGARD TO BERTHA`S HEALTH BUT STORM FORCE WINDS HAVE BEEN NOTED AS
WELL THEREFORE WE MUST CONTINUE TO EXPECT BERTHA TO MAINTAIN
INTENSITY FOR NOW.

AVIATION...BERTHA CONTINUES TO MOVE RAPIDLY WEST NORTHWEST AT 18
KNOTS. AVIATION INTEREST SHOULD NOTE THAT CONDITIONS WILL
DETERIORATE IN ALL AREAS WITH TNCM AND TKPK ALREADY EXPERIENCING
GUSTY WINDS AND LOWERING CIGS NOW. EXPECT MTN OBSCURATIONS AND
POSSIBLE STORM FORCE WINDS IN THE USVI BY BY 02/09Z AND IN PUERTO
RICO BY 02/12Z.

MARINE...NO CHANGES EXCEPT WIND GUSTS SHOULD NOT EXCEED 55 KT.

PREV DISCUSSION... /ISSUED 250 PM AST FRI AUG 1 2014/

SYNOPSIS... AT 2 PM AST...TROPICAL STORM BERTHA WAS LOCATED NEAR 14.5N
AND 60.3W OR NEAR 480 MILES EAST SOUTHEAST OF PONCE PR. TROPICAL
STORM WARNING IN EFFECT OF PUERTO RICO AND THE U.S. VIRGIN
ISLANDS.

DISCUSSION...SHOWERS WITH THUNDERSTORMS DEVELOPED THIS AFTERNOON
OVER THE NORTHWEST SECTION OF PUERTO RICO. STRONG THUNDERSTORMS
WITH FREQUENT LIGHTING WAS OBSERVED OVER SAN SEBASTIAN...WHERE
THUNDERSTORMS WIND DAMAGE WERE REPORTED. THIS ACTIVITY IS EXPECTED
TO DISSIPATED NEAR SUNSET. ONLY LIGHT PASSING SHOWERS ARE EXECUTED
TO PREVAIL TONIGHT OVER THE U.S. VIRGIN ISLANDS AND EASTERN PUERTO
RICO.

MAIN WEATHER FEATURE WHICH WILL AFFECT THE LOCAL AREA NEXT 24 TO
36 HOURS IS TROPICAL STORM BERTHA. TROPICAL STORM BERTHA WAS
LOCATED NEAR 480 MILES EAST SOUTHEAST OF PONCE THIS AFTERNOON.
BERTHA WILL CONTINUE TO MOVE WEST NORTHWEST AND WILL APPROACH THE
U.S VIRGIN ISLANDS AND PUERTO RICO ON SATURDAY. WEATHER IS
EXPECTED TO DETERIORATE RAPIDLY STARTING SATURDAY MORNING AND
CONTINUING THROUGH SATURDAY NIGHT. REMEMBER...A TROPICAL STORM
WARNING IS IN EFFECT FOR ALL OF PUERTO RICO AND THE U.S VIRGIN
ISLANDS.  TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN
THE NEXT 24 HOURS. THEREFORE...FINAL PREPARATIONS TO PROTECT LIFE AND
PROPERTY SHOULD BE COMPLETED BEFORE CONDITIONS DETERIORATE. THE
ONSET OF GUSTY WINDS AND HEAVY RAINS CAN CAUSE OUTSIDE ACTIVITIES
TO BECOME DANGEROUS. REFER TO LATEST HURRICANE LOCAL STATEMENT FOR
FURTHER INFORMATION.

AVIATION...BRIEF MVFR CIGS DUE SCT SHRA/TSRA WILL CONTINUE AT
LEAST UNTIL 21Z MAINLY OVER TJBQ. VFR CONDS WILL PREVAIL AT ALL
OTHER TAF SITES FOR THE REST OF TODAY. HOWEVER...THE PROXIMITY OF TC
BERTHA WILL START TO IMPACT TNCM AND TKPK TONIGHT AND THE REST OF
THE TERMINAL EARLY SATURDAY MORNING. THEREFORE...MVFR CONDS WITH
PERIODS OF BRIEF IFR ARE EXPECTED THROUGH THE END OF THE FCST
PERIOD. E-NE WINDS AT 15 TO 25 KTS BELOW FL100 BCMG ESE AND HIGHER
AFTER 02/12Z.

MARINE...SEAS BELOW 6 FT TONIGHT INCREASING 6-10 FT THROUGH SATURDAY
WITH HIGHER SEAS TO THE RIGHT OF THE CENTER OF THE TRACK OF TC
BERTHA. SUSTAINED WINDS 40-45 KT WITH GUSTS UP TO 60 KT. WINDS AND
SEAS BEGIN TO IMPROVE RAPIDLY LATE SAT NIGHT.

FIRE WEATHER...A RED FLAG WARNING CONTINUES IN EFFECT FOR SAINT
CROIX. THIS WARNING WILL EXPIRE AT 5 PM AST THIS AFTERNOON.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  79  86  75  92 / 100 100  90  40
STT  81  82  79  87 / 100 100  90  10

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...TROPICAL STORM WARNING FOR CENTRAL INTERIOR-CULEBRA-EASTERN
     INTERIOR-MAYAGUEZ AND VICINITY-NORTH CENTRAL-NORTHEAST-
     NORTHWEST-PONCE AND VICINITY-SAN JUAN AND VICINITY-
     SOUTHEAST-SOUTHWEST-VIEQUES-WESTERN INTERIOR.

VI...TROPICAL STORM WARNING FOR ST CROIX-ST. THOMAS/ST. JOHN/ADJACENT
     ISLANDS.

COASTAL WATERS...
&&

$$

13/12





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