Flash Flood Warning 58, NWS JSJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1000 AM AST TUE OCT 24 2000

PREVIOUS FCST LOOKS GOOD...SO WILL NOT UPDATE AT THIS TIME. A BROAD
UPPER LEVEL TROUGH CONTINUES TO DIG SOUTH TOWARDS THE WESTERN
CARIBBEAN. ITS SOUTHEAST QUADRANT...AREA OF BEST UPPER DIVERGENCE
AND DEEP CONVECTION...ALREADY OVER SOUTHERN BAHAMAS...APPROACHING TO
HISPANIOLA...WILL GRADUALLY DESTABILIZED MORE OUR LOCAL ATMOSPHERE
THROUGH FRIDAY. THIS FEATURE IS INDUCING WINDS FROM THE SOUTH
MAINTAINING A THETA-E RIDGE OVER THE LOCAL REGION. MRF SHOWS BROAD
THETA-E RIDGE WITH AXIS OVER PUERTO RICO THIS AFTERNOON...BUT
DISPLACING IT OVER EASTERN HISPANIOLA BY FRIDAY. AVN PLACES UPPER
LEVEL DIVERGENCE ACROSS THE REGION THROUGH THURSDAY...AND MIDDLE
LAYER UPWARD MOTION FROM THIS AFTERNOON THROUGH WEDNESDAY NIGHT.
RADAR...MODELS AND VIS SATELLITE IMAGERY INDICATED LIGHT LOW LEVEL
WIND FLOW ADVECTING SOME CLOUDS AND SHOWERS FROM THE CARIBBEAN WATER
INTO PUERTO RICO AND THE USVI. SKIES CLEARED UP THIS MORNING...SO
EXPECT DIURNAL HEATING TO PRODUCE SEA BREEZES ALONG ALL COASTS THIS
AFTERNOON. BEST LOW LEVEL CONVERGENCE SHOULD BE ALONG THE NORTH
COASTS AND ACROSS THE INTERIOR MOUNTAINS.

ON THE MARINE SIDE...EXPECTING N SWELLS TO INCREASE SEAS 6 TO 7 FT
OVER THE ATLANTIC WATERS...MONA AND ANEGADA PASSAGES WEDNESDAY NIGHT AND
THURSDAY.

EQUIPMENT: WSR-88D RETURNED TO SERVICE. NO OTHER PROBLEMS ATTM.

.SJU...
.PR...NONE.
.VI...NONE.

ROCHE

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-VIZ001-002-242200-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1221 PM AST TUE OCT 24 2000

...STRONG TO SEVERE THUNDERSTORMS POSSIBLE TODAY...
THERE IS SLIGHT RISK OF THUNDERSTORMS BECOMING SEVERE THIS
AFTERNOON ESPECIALLY IN THE INTERIOR AND NORTHERN SECTIONS OF PUERTO
RICO. THESE THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE INTERIOR
MOUNTAINS AND MOVE NORTHWARD AROUND 10 MPH TOWARDS THE NORTH COAST
OF PUERTO RICO. THE MAIN THREAT FROM THESE THUNDERSTORMS WILL BE
DAMAGING WIND GUST...NICKEL SIZE HAIL AND DANGEROUS LIGHTNING. IN
ADDITION SHOWERS AND THUNDERSTORMS OVER THE MARINE COASTAL WATERS
WILL LIKELY SPAWN WATERSPOUTS. HEAVY RAINFALL AND SUBSEQUENT FLASH
FLOODING WILL ALSO BE A CONCERN ACROSS PUERTO RICO AND THE U.S
VIRGIN ISLANDS. HEAVY RAINFALL DURING THE PAST COUPLE OF DAYS...HAVE
LEFT SOILS SATURATED AND ANY ADDITIONAL HEAVY RAIN THIS AFTERNOON
AND TONIGHT WILL LIKELY LEAD TO RAPID RUNOFF AND FLASH FLOODING.

DISCUSSION...A BROAD UPPER LEVEL TROUGH EXTENDING FROM THE BAHAMAS
SOUTH TO THE CENTRAL CARIBBEAN WILL PROVIDE FAVORABLE CONDITIONS FOR
THE DEVELOPMENT OF THUNDERSTORMS THROUGH TONIGHT. IN ADDITION...THE
ATMOSPHERE HAS BECOME VERY UNSTABLE DUE TO AN INCREASE IN MOISTURE
AND COLD AIR ALOFT.

WEATHER SPOTTERS SHOULD REMAIN ALERT THIS AFTERNOON AND REPORT ANY
SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE OR CIVIL DEFENSE
OFFICIALS.

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
MV