Flash Flood Warning 12, NWS JSJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
400 AM AST MON MAY 6 2001

THE SURFACE LOW TO THE NORTH OF HISPANIOLA AND EAST OF THE BAHAMAS
AND FAVORABLE UPPER LEVEL DYNAMICS CONTINUES TO SUPPORT CONVECTION
OVER PUERTO RICO AND THE U.S. VIRGIN ISLANDS. CURRENTLY THE HEAVIEST
RAIN BANDS EXTEND FROM SOUTH OF PUERTO RICO TO THE EASTERN COASTAL
WATERS OF PUERTO RICO AND SLOWLY DRIFTING TO THE EAST.

THE CONDITIONS FOR TODAY WILL CONTINUE TO BE FAVORABLE FOR
CONVECTION AS THERE IS ABUNDANT LOW LEVEL MOISTURE AND FAVORABLE MID
TO UPPER LEVEL DYNAMICS AND LARGE SCALE LIFT. CLOUD COVER MAY ACT TO
INHIBIT SOME OF THE DAYTIME HEATING EFFECTS...BUT BOTH IR AND WATER
VAPOR IMAGERY ARE INDICATING THAT THE MID TO UPPER LEVELS ARE
BEGINNING TO DRY OUT. THIS IS ALSO INDICATED IN THE MODEL GUIDANCE.
SO GIVEN THE DAY TIME HEATING...LOW LEVEL MOISTURE AND
AFOREMENTIONED FAVORABLE DYNAMICS...MODERATE TO HEAVY SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED.

THE FLASH FLOOD WATCH IS IN EFFECT UNTIL 400 PM THIS AFTERNOON FOR
ALL OF PUERTO RICO AND WILL INCLUDE VIEQUES AND CULEBRA. VIEQUES AND
CULEBRA ARE INCLUDED FOR THE SHORT TERM...THE CURRENT RAIN BANDS ARE
STARTING TO EFFECT THEM NOW. WITH MOST OF THE REMAINING PARTS OF
PUERTO RICO RECEIVING COPIOUS RAIN SUNDAY...ANY ADDITIONAL RAINFALL
WILL QUICKLY RUN OFF AND URBAN FLOODING...RIVER FLOODING AND
MUDSLIDES ARE POSSIBLE.

FOR TUESDAY...CONTINUED ABUNDANCE OF LOW LEVEL MOISTURE WILL BE A
FACTOR...BUT A LOW AND MID LEVEL RIDGE STARTS TO BUILD IN FROM THE
EAST AND THE DYNAMICS BECOME LESS FAVORABLE FOR CONVECTION.
HOWEVER...THE AVAILABLE LOW LEVEL MOISTURE IS EXPECTED TO BE HIGH
ENOUGH THAT DAY TIME HEATING WILL RESULT IN SHOWERS.

EQUIPMENT: NO PROBLEMS AT THIS TIME.

.SJU...
.PR...FFA PRZALL TIL 20Z.
.VI...NONE.

DIEHL

WRITTEN TEXT FORECASTS (IN ENGLISH OR SPANISH)...SATELLITE IMAGERY
...DOPPLER RADAR DATA...AND A VIRTUAL LIBRARY OF WEATHER INFORMATION
CAN BE FOUND AT THE NWS SAN JUAN WEB SITES AT:

HTTP://WWW.SRH.NOAA.GOV/SJU (ALL LOWER CASE).

    OR

HTTP://WWW.UPR.CLU.EDU/NWS (ALL LOWER CASE).

PRZ001>013-VIZ001-002-072200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JUAN PR
630 AM AST MON MAY 7 2001

A SURFACE TROUGH LOCATED TO THE EAST OF PUERTO RICO IS MOVING TO THE
EAST AND IS NOW AFFECTING THE U.S. VIRGIN ISLANDS. CONSIDERABLE
CLOUDINESS AND LOW LEVEL MOISTURE ASSOCIATED WITH WITH IT WILL
RESULT IN SHOWERS AND THUNDERSTORMS PRODUCING HEAVY AND VERY HEAVY
RAINFALL FOR THE U.S. VIRGIN ISLANDS TODAY . THIS WILL MAINTAIN A
HIGH PROBABILITY OF HEAVY RAIN LEADING TO FLASH FLOODING ACROSS MUCH
OF THE U.S VIRGIN ISLANDS TODAY.

FOR PUERTO RICO...DUE TO COPIOUS RAINFALL ON SUNDAY...AFTERNOON
SHOWERS AND THUNDERSTORMS WILL LIKELY RESULT IN FLASH FLOODING AND
RIVER FLOODING DUE TO ALREADY SATURATED GROUNDS AND RIVERS.

RESIDENTS AND VISITORS OF PUERTO RICO...THE U.S VIRGIN
ISLANDS...SPOTTERS AND EMERGENCY MANAGERS SHOULD MONITOR THE WEATHER
CLOSELY THROUGH TODAY AND THIS EVENING...AND BE PREPARED TO ACT
QUICKLY SHOULD WEATHER CONDITIONS WARRANT.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE
PUERTO RICO AND U.S. VIRGIN ISLANDS WEBSITE ON THE INTERNET AT (ALL
LOWERCASE LETTERS).

HTTP://WWW.SRH.NOAA.GOV/SJU
             OR
HTTP://WWW.UPR.CLU.EDU/NWS