Flash Flood Warning 93, NWS JSJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
538 AM AST WED OCT 6 2010

.SYNOPSIS...A MID TO UPPER LEVEL TROUGH AXIS AND ASSOCIATED TUTT LOW
WILL REMAIN ANCHORED ACROSS THE ATLANTIC AND JUST NORTH AND
NORTHWEST OF THE LOCAL AREA THROUGH THE END OF THE WEEK. THIS WILL
MAINTAIN FAVORABLE UPPER LEVEL CONDITIONS ACROSS THE ISLANDS AND
SURROUNDING WATERS. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A
BROAD AREA OF LOW PRESSURE AND NOW SUBTROPICAL DEPRESSION
SEVENTEEN LOCATED NEAR LATITUDE 22.2 NORTH...LONGITUDE 67.0 WEST...
WILL CONTINUE TO LIFT DEEP TROPICAL MOISTURE ACROSS THE REGION
THROUGH THE END OF THE WEEK. THIS FEATURE IS HELPING TO CREATING
AN AREA OF STRONG LOW LEVEL CONVERGENCE AND TIGHT PRESSURE GRADIENT
ACROSS THE VIRGIN ISLANDS AND ANEGADA PASSAGE...AS IT PULLS
NORTHWARDS OF THE LOCAL AREA.

&&

.DISCUSSION...THE UPPER AND LOW LEVEL FEATURES AFOREMENTIONED WILL
COMBINE WITH THE VERY MOIST AND UNSTABLE LOCAL ENVIRONMENT AND
LOCAL EFFECTS... TO CONTINUE TO PRODUCE PERIODS OF SHOWERS AND
THUNDERSTORMS ACROSS THE LOCAL ISLANDS THROUGH AT LEAST THURSDAY
AS THIS SYSTEM SLOWLY LIFTS NORTHWARDS.

EXPECT FREQUENT CLUSTERS OF SHOWERS AND THUNDERSTORMS TO DEVELOP
OVER THE CARIBBEAN WATERS AND LIFT NORTH NORTHEASTWARD MAINLY ACROSS
THE CULEBRA...VIEQUES AND THE EASTERN HALF OF PUERTO RICO DURING THE
MORNING HOURS...BUT EVENTUALLY SPREADING WESTWARDS ACROSS THE REST
OF PUERTO RICO DURING THE REST OF THE DAY. THIS WILL AGAIN RESULT IN
FLASH AND RIVER FLOODING ACROSS PARTS OF PUERTO RICO AND DEFINITELY
CONTINUE WITH FLOODING PROBLEMS ACROSS THE VIRGIN ISLANDS. EXPECT
THIS UNSETTLED WEATHER PATTERN...TO CONTINUE ACROSS THE REGION
THROUGH THEN END OF THE WORK WEEK.

THEREFORE...AS STRESSED IN PREVIOUS DAYS...CONSIDERING THE PRESENT
STATE OF THE GROUND AND RIVER CONDITIONS WHICH ARE RUNNING HIGH IN
MOST AREAS...EXPECT HAZARDOUS WEATHER CONDITIONS TO CONTINUE ACROSS
THE ISLANDS AS WELL AS THE LOCAL WATERS. SIGNIFICANT PERIODS OF
ACTIVE WEATHER...WITH HEAVY RAINFALL...AREAS OF FLASH AND RIVER
FLOODING...AND MUDSLIDES...WILL REMAIN LIKELY. IT SHOULD ALSO BE
NOTED...THAT ALTHOUGH IT IS NOT EXPECTED TO BE CONTINUOUSLY RAINING
ACROSS THE ISLANDS OVER THE NEXT FEW DAYS...STILL LOOK FOR PERIODS
OF HEAVY RAINFALL WITH FLASH FLOODING POTENTIAL TO CONTINUE. AS A
RESULT...THE FLASH FLOOD WATCH FOR ALL OF PUERTO RICO AND THE U.S.
VIRGIN ISLANDS WILL CONTINUE THROUGH THURSDAY AFTERNOON. THEREAFTER...
AND WILL CONTINUE TO CLOSELY MONITOR THROUGH THE WEEKEND AS THE
CONTINUED WET WEATHER PATTERN MAY PERSIST INTO THE UPCOMING WEEKEND
BASED ON SOME OF THE LATEST MODEL GUIDANCE. STAY TUNED FOR FURTHER
UPDATES AND INFO THROUGHOUT THE DAY.

&&

.AVIATION...MVFR CONDITIONS WILL PREVAIL ACROSS TIST...TISX...TNCM...
TKPK...AND TJPS THROUGH AT LEAST 07/00Z. BRIEF IFR CONDITIONS ARE
LIKELY ACROSS THESE AREAS IN SHRA/ISOLD TSRA. VFR CONDS WILL
PREVAIL ACROSS TJSJ...TJMZ...TJBQ THIS MORNING...WITH BRIEF
PERIODS OF MVFR. MVFR TO IFR CONDITIONS ARE LIKELY ACROSS TJSJ
THIS AFTERNOON IN SHRA/ISOLD TSRA. PREVAILING WEST TO SOUTHWEST
LOW LVL WIND FLOW OF 15 TO 25 KTS EXPECTED...WITH HIGHER GUSTS
LIKELY IN SHOWERS AND THUNDERSTORMS.

&&

.MARINE...PLEASE REFER TO THE LATEST MARINE WEATHER STATEMENT (SJUMWWSJU)
AND THE COASTAL WATERS FORECAST (SJUCWFSJU) FOR LATEST INFORMATION
ON THE LOCAL MARINE CONDITIONS.

&&

.CLIMATE....AS OF MIDNIGHT AST ON 5 OCT 2010...6.61 INCHES OF
RAINFALL HAD ACCUMULATED AT THE SAINT THOMAS CYRIL E. KING
AIRPORT IN CHARLOTTE AMALIE...MAKING IT THE 5TH WETTEST DAY ON
SAINT THOMAS SINCE RECORD KEEPING BEGAN...AND THE WETTEST DAY
SINCE SEPTEMBER 15TH 2004 WHEN JEANNE TRACKED ACROSS THE LOCAL
ISLANDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  88  77  87  78 /  60  50  60  50
STT  87  79  89  80 /  80  60  60  50

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON 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...FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR ST CROIX-ST.
     THOMAS/ST. JOHN/ADJACENT ISLANDS.

&&

07/09

HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN
ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
640 AM AST WED OCT 6 2010

AMZ710>745-PRZ001>013-071045-
SAN JUAN AND VICINITY-NORTHEAST-SOUTHEAST-EASTERN INTERIOR-
NORTH CENTRAL-CENTRAL INTERIOR-PONCE AND VICINITY-NORTHWEST-
WESTERN INTERIOR-MAYAGUEZ AND VICINITY-SOUTHWEST-CULEBRA-VIEQUES-
THE NEARSHORE AND OFF SHORE ATLANTIC AND CARIBBEAN COASTAL WATERS-
640 AM AST WED OCT 6 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE
ADJACENT COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT
NEWLY FORMED SUBTROPICAL DEPRESSION 17 LOCATED OVER 200 MILES
NORTH NORTHWEST OF LOCAL AREA IWLL CONTINUE TO BRING MORE TROPICAL
MOISTURE ACROSS THE REGION AS IT SLOWLY LIFTS NORTH NORTHWEST.
SOILS ACROSS THE ISLANDS REMAIN AT OR NEAR SATURATION...AND RIVER
AND STREAMS ACROSS MUCH OF PUERTO RICO CONTINUE AT HIGH LEVELS.
ANY ADDITIONAL MODERATE TO HEAVY RAINFALL WILL ONLY AGGRAVATE THE
SITUATION AND LEAD TO FLASH AND RIVER FLOODING.IN ADDITION...
MUDSLIDES WILL REMAIN POSSIBLE IN AREAS OF STEEP TERRAIN DUE TO
LOOSE SOIL

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
SUBTROPICAL DEPRESSION 17 WILL CONTINUE TO PULL TROPICAL MOISTURE
ACROSS THE REGION ON THURSDAY AS IT SLOWLY MOVES AWAY FROM THE
AREA. POTENTIAL FOR SHOWERS AND ISOLATED THUNDERSTORM DEVELOPMENT
EACH DAY WILL REMAIN HIGH AND THIS WILL LEAD TO AT LEAST URBAN
AND SMALL STREAM FLOODING AND POSSIBLY SOME RIVER FLOODING...ESPECIALLY
DURING THE AFTERNOON AND EARLY EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...SIGNIFICANT RAINFALL
ACCUMULATIONS AND/OR FLOODING REPORTS WOULD BE GREATLY
APPRECIATED.

AMZ715-725-VIZ001-002-071045-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
640 AM AST WED OCT 6 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND
THE ADJACENT COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT
NEWLY FORMED SUBTROPICAL DEPRESSION 17 LOCATED OVER 200 MILES
NORTH NORTHWEST OF LOCAL AREA IWLL CONTINUE TO BRING MORE TROPICAL
MOISTURE ACROSS THE REGION AS IT SLOWLY LIFTS NORTH NORTHWEST.
SOIL ACROSS THE ISLANDS REMAIN AT OR NEAR SATURATION...AND
ANY ADDITIONAL MODERATE TO HEAVY RAINFALL WILL ONLY AGGRAVATE THE
SITUATION AND LEAD TO AT LEASE SOME URBAN AND SMALL STREAM
FLOODING. IN ADDITION... MUDSLIDES WILL REMAIN POSSIBLE IN AREAS
OF STEEP TERRAIN DUE TO LOOSE SOIL.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
SUBTROPICAL DEPRESSION 17 WILL CONTINUE TO PULL TROPICAL MOISTURE
ACROSS THE REGION ON THURSDAY AS IT SLOWLY MOVES AWAY FROM THE
AREA. POTENTIAL FOR SHOWERS AND ISOLATED THUNDERSTORM DEVELOPMENT
EACH DAY WILL REMAIN HIGH AND THIS WILL LEAD TO AT LEAST URBAN
AND SMALL STREAM FLOODING AND POSSIBLY SOME RIVER FLOODING...ESPECIALLY
DURING THE AFTERNOON AND EARLY EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...SIGNIFICANT RAINFALL
ACCUMULATIONS AND/OR FLOODING REPORTS WOULD BE GREATLY
APPRECIATED.