Flash Flood Warning 133, NWS JSJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
620 AM AST SAT NOV 6 2010

.SYNOPSIS...AT MID AND UPPER LEVELS...A STRONG MID LATITUDE TROUGH
OVER EASTERN OHIO THAT IS FED BY A JET OUT OF THE GULF OF MEXICO
AND A STRONG TUTT LOW NEAR 34 NORTH 44 WEST ARE CLOSING IN ON A
VERY SHARP RIDGE THAT STRETCHES FROM THE MONA CHANNEL TO WELL
BEYOND BERMUDA. AS THE TROUGH LIFTS NORTHEAST THE TUTT LOW WILL BE
FORCED SOUTHWEST AND THEN EAST AGAIN LEAVING A MUCH FLATTENED HIGH
PRESSURE OVER THE ENTIRE CARIBBEAN. A SHORT WAVE WILL DEEPEN
ACROSS THE DOMINICAN REPUBLIC AND PUERTO RICO ON FRIDAY. THIS
TROUGH WILL BE REINFORCED BY A SECOND SHORTWAVE ON SUNDAY NIGHT
BEFORE RIDGING RETURNS TO THE AREA THE WEEK AFTER NEXT.

AT LOWER LEVELS...RECENTLY WEAKENED TROPICAL STORM TOMAS IS MOVING
NORTHEAST AT 15 MPH INTO THE SOUTHWEST NORTH ATLANTIC AND ALREADY
SHOWING SOME SIGNS OF CURVING TO THE RIGHT AS UPPER LEVEL FLOW
GUIDES IT ACROSS THE UPPER LEVEL RIDGE. IT IS EXPECTED TO MOVE TO
THE NORTH OF PUERTO RICO SUNDAY NIGHT...DRAGGING A WEAK AND BROAD
TROUGH ACROSS PUERTO RICO...THE U.S. VIRGIN ISLANDS AND THE
CARIBBEAN SEA THAT THREATENS TO LINGER THROUGH THE REST OF THE
WEEK DESPITE THE DECAY AND DEPARTURE OF TOMAS.

&&

.DISCUSSION...MODERATE TO HEAVY RAIN WITH THUNDER HAS SET UP
ACROSS SOUTH CENTRAL AND SOUTHWEST PUERTO RICO OVERNIGHT AND HAS
SENT...AND LIKELY WILL CONTINUE TO SEND...SOME AREA RIVERS ABOVE
THEIR FLOOD STAGES. SATELLITE IMAGERY SHOWED CONSIDERABLE COOLING
OF TOPS OF THE RAINBAND FEEDER TO TOMAS TO THE SOUTH OF PUERTO
RICO BETWEEN 06/0515Z AND 06/0830Z AND RADAR HAS SHOWN RENEWED
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS TO THE SOUTH OF PUERTO
RICO. A FEW SHOWERS HAVE BRUSHED THE U.S. VIRGIN ISLANDS
OVERNIGHT...BUT THE BAND HAS NOT EXTENDED TO THEIR AREA YET AND IS
NOT EXPECTED TO DO SO DURING THE NEXT 12 HOURS AT LEAST. ALTHOUGH
MUCH WILL DEPEND ON THE TRAJECTORY OF TOMAS...RAINFALL IS EXPECTED
TO CONTINUE IN THE NEAR-TERM REGARDLESS OF ACTUAL TRACK DUE TO
CONVERGENCE INTO THE STORM AT LOWER LEVELS AND DIVERGENCE ALOFT AT
UPPER LEVELS IN THE RIDGE OVER THE AREA. AFTER MONDAY WHETHER
TOMAS LAYS OVER TO THE EAST OR MOVES MORE TO THE NORTHEAST WILL
HAVE A MUCH MORE SIGNIFICANT IMPACT ON THE FORECAST TUESDAY
THROUGH THE REST OF THE WEEK. SHOULD IT LAY OVER...OR...EVEN
RETURN IN A MUCH MORE WEAKENED STATE...RAIN WILL CONTINUE OVER THE
AREA AND FLOODING WOULD BE HIGHLY LIKELY. IF IT MOVES TO THE
NORTHEAST SUFFICIENTLY...FLOW NEAR THE SURFACE WOULD BECOME
NORTHWEST OR NORTH AND RAIN CHANCES WOULD LESSEN...THOUGH NOT
COMPLETELY DISAPPEAR.

AT PRESENT A FLASH FLOOD WATCH REMAINS IN EFFECT FOR ALL OF PUERTO
RICO AND THE U.S. VIRGIN ISLANDS FOR THE LIKELIHOOD OF RAPID RIVER
RISES TO FLOOD WHERE SHOWERS FROM THE RAIN BAND OR BANDS CROSS PUERTO
RICO TODAY THROUGH SUNDAY AND THE U.S. VIRGIN ISLANDS SUNDAY AND
MONDAY. WOULD EXPECT SHOWERS TO BECOME HEAVIER WITH DAYTIME
HEATING AND SOME AREAS WILL BE MORE AFFECTED THAN OTHERS WHEN THIS
HAPPENS...ESPECIALLY INTERIOR MOUNTAIN AREAS. PLEASE SEE THE FLASH
FLOOD WATCH FOR DETAILS REGARDING AMOUNTS AND IMPACTS.

&&

.AVIATION...
A MODERATE SOUTHEAST LOW LEVEL WIND FLOW WILL CONTINUE TO
TRANSPORT NUMEROUS SHOWERS WITH ISOLATED THUNDERSTORMS ACROSS MOST
OF THE TAF SITES. TEMPO MVFR CONDITIONS CAN BE EXPECTED ACROSS
TJPS...TJMZ...AND TJBQ THROUGH AT LEAST 06/22Z. BRIEF PERIODS OF
MVFR CONDITIONS CAN BE EXPECTED ELSEWHERE IN SHRA OR TSRA LATER
THIS AFTERNOON. WINDS WILL CONTINUE MAINLY SOUTHEAST AT 10 TO 15
KTS WITH HIGHER GUSTS IN SHOWERS. MOUNTAINS WILL BE OBSCURED.

&&

.MARINE...WINDS WILL PEAK TODAY OVER THE AREA AND HOLD SEAS AT OR
JUST BELOW SMALL CRAFT ADVISORY CRITERIA. SOME AREAS WILL
EXPERIENCE VERY STRONG GUSTS NEAR THUNDERSTORMS. SEAS WILL RISE IN
THE ATLANTIC ON SUNDAY WHEN WAVES FROM TOMAS APPROACH THE AREA.
SEAS WILL REMAIN HIGH IN THE ATLANTIC FOR MUCH OF THE REST OF THE
WEEK. CONDITIONS WILL BE MUCH MORE FAVORABLE IN THE CARIBBEAN ONCE
THE RAIN BANDS FROM TOMAS HAVE DISSIPATED OR MOVED EAST.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  87  74  84  75 /  70  70  80  70
STT  87  77  83  77 /  60  90  80  70

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR ALL OF PUERTO RICO.

     SCA...AMZ710.

VI...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR ALL OF THE
U.S. VIRGIN ISLANDS.

     SCA...AMZ710.

&&

71/12

HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN
ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
607 AM AST SAT NOV 6 2010

AMZ710>745-PRZ001>013-071015-
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-
607 AM AST SAT NOV 6 2010

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

.DAY ONE...TODAY AND TONIGHT
NUMEROUS SHOWERS WITH ISOLATED THUNDERSTORMS WILL CONTINUE
AFFECTING PUERTO RICO THROUGH TONIGHT. THIS WILL LEAD TO HIGH RISK
OF FLASH FLOODING ACROSS MOST OF THE AREA. PEOPLE LIVING ALONG OR
NEAR RIO LA PLATA...RIO GRANDE DE ARECIBO...RIO GUANAJIBO AND RIO
CULEBRINAS SHOULD BE ALERT FOR POSSIBLE FLASH FLOODING. ELSEWHERE
URBAN AND SMALL STREAM FLOODING WILL BE POSSIBLE. THEREFORE...A FLASH
FLOOD WATCH IS IN EFFECT FOR ALL PUERTO RICO THROUGH AT LEAST
MONDAY AFTERNOON.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY
THE OVERALL MOIST ENVIRONMENT COMBINED WITH LOCAL AND DIURNAL
EFFECTS...ALONG WITH THE PREVAILING SOUTHEAST WIND FLOW...WILL
CONTINUE TO AID IN PRODUCING ACTIVE WEATHER CONDITIONS ACROSS THE
ISLANDS. THEREFORE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR
PUERTO RICO UNTIL AT LEAST MONDAY AFTERNOON.

.SPOTTER INFORMATION STATEMENT...INFORMATION ON RAINFALL TOTAL
ACCUMULATIONS WILL BE APPRECIATED.

AMZ715-725-VIZ001-002-071015-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
607 AM AST SAT NOV 6 2010

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

.DAY ONE...TODAY AND TONIGHT
NUMEROUS SHOWERS WITH ISOLATED THUNDERSTORMS WILL SPREAD OVER THE
U.S. VIRGIN ISLANDS LATER THIS AFTERNOON AND TONIGHT . THIS WILL
LEAD TO HIGH RISK OF FLASH FLOODING ACROSS MOST OF THE ISLANDS.
THEREFORE...A FLASH FLOOD WATCH IS IN EFFECT UNTIL AT LEAST
MONDAY AFTERNOON.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY
THE OVERALL MOIST ENVIRONMENT COMBINED WITH LOCAL AND DIURNAL
EFFECTS...ALONG WITH THE PREVAILING SOUTHEAST WIND FLOW...WILL
CONTINUE TO AID IN PRODUCING ACTIVE WEATHER CONDITIONS ACROSS THE
ISLANDS. THEREFORE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR
THE U.S. VIRGIN ISLANDS UNTIL AT LEAST MONDAY AFTERNOON.

.SPOTTER INFORMATION STATEMENT... INFORMATION ON RAINFALL TOTAL
ACCUMULATIONS WILL BE APPRECIATED.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN JUAN PR
206 AM AST SAT NOV 06 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1230 AM     FLASH FLOOD      AIBONITO                18.14N 66.27W
11/06/2010                   AIBONITO           PR   OTHER FEDERAL

            U.S.G.S RIVER SENSOR INDICATED RIO LA PLATA IN AIBONITO
            WENT OUT OF ITS BANKS.

0146 AM     FLASH FLOOD      COMERIO                 18.22N 66.22W
11/06/2010                   COMERIO            PR   OTHER FEDERAL

            RIO DE LA PLATA AT COMERIO WENT OUT OF ITS BANKS.

&&

FCASTRO