Debris Flow in Puerto Rico, May 23, 2004

PUERTO RICO AND U.S. VIRGIN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
410 PM AST SUN MAY 23 2004

.UPDATE...
NO MUCH TIME TO WRITE A AFD DUE TO LOTS OF NON ROUTINE PRODUCTS
ISSUED THIS AFTERNOON. PREVIOUS DISCUSSION PERSIST AT THIS TIME.

.SYNOPSIS...MID TO UPPER LEVEL SUBTROPICAL RIDGING CONTINUES TO
EXTEND AND BUILD INTO THE EASTERN CARIBBEAN AS A BROAD TROUGH
EXTENDS FROM THE CENTRAL ATLANTIC SOUTHWEST ACROSS THE WEST ATLANTIC
OVER CUBA INTO THE WESTERN CARIBBEAN. THE SUBTROPICAL JET WHICH
CONTINUES TO RIDE THE PERIPHERY OF THIS BUILDING RIDGE AND CROSSES
INTO THE ATLANTIC...HAS SHIFTED FURTHER THE NORTH OF THE LOCAL
REGION. WEAK MID LEVEL SHORT WAVE VORTICIES IS STILL APPARENT MOVING
ALONG THE TROUGH ACROSS THE WEST AND CENTRAL CARIBBEAN TOWARDS
PORTIONS OF HISPANOLA. THE UPPER LEVEL WINDS OVER THE LOCAL AREA
HAVE SOMEWHAT DECREASED...HOWEVER THE OVERALL PATTERN WILL CONTINUE
TO MAINTAIN UPPER LEVEL SUPPORT ACROSS THE REGION. HIGH PRESSURE IN
THE LOW LEVELS CONTINUE TO DOMINATE THE ATLANTIC...MEANWHILE AN
ELONGATED TROUGH AND ASSOCIATED LOW PRESSURE CENTERED ACROSS THE
CENTRAL CARIBBEAN...STRETCHES NORTH NORTHEAST INTO THE NORTHEAST
CARIBBEAN AND OVER THE LOCAL AREA. A WEAK WAVE IN THE EASTERLY WIND
FLOW NOW ACROSS THE WINDWARD AND LEEWARD ISLANDS CONTINUE TO SLOWLY
MOVE WEST. THE COMBINATION OF THESE FEATURE IS ASSISTING IN
MAINTAINING THE EAST SOUTHEAST LOW LEVEL WIND FLOW WITH ABUNDANT LOW
LEVEL MOISTURE ADVECTION.

&&

.DISCUSSION...CLOUDY SKIES CONTINUED ACROSS THE LOCAL AREA OVERNIGHT
INTO THE EARLY MORNING HOURS. A MIXTURE OF LIGHT RAIN AND SCATTERED
TO NUMEROUS SHOWER ACTIVITY WITH AN ISOLATED EMBEDDED AN
THUNDERSTORM OR TWO CONTINUED TO MOVE NORTHWEST ACROSS THE REGIONAL
WATERS AND AFFECT THE MAJORITY OF THE LOCAL ISLANDS. MODEL GUIDANCE
REMAIN PERSISTENT AND CONTINUE TO SUGGEST THAT COPIOUS AMOUNTS OF
MOISTURE FROM SURFACE TO UPPER LEVELS WILL CONTINUE OVER THE LOCAL
AREA THROUGH EARLY NEXT WEEK. SOUNDINGS ACROSS THE REGION REMAIN
VERY MOIST AND UNSTABLE WITH GOOD TROPICAL MOISTURE AND PRECIPITABLE
WATER BETWEEN 1.80 TO 2.38 INCHES. THE LOW PRESSURE SYSTEM ACROSS
THE CARIBBEAN WILL CONTINUE TO MOVE NORTH NORTHWEST AND IN DOING SO
WILL MAINTAIN THE PRESENT WET PATTERN ACROSS THE LOCAL REGION
THROUGH AT LEAST MONDAY AND THEN CONDITIONS SHOULD THEN TAPER OFF ON
TUESDAY AND IMPROVING BY MID WEEK. EXPECT AN ACTIVE...CLOUDY AND
WET WEATHER PATTERN ACROSS THE AREA TODAY THROUGH MONDAY WITH
INTERMITTENT...VERY HEAVY RAIN AND OCCASIONAL THUNDERSTORM ACTIVITY.
THE RISK FOR FLASH FLOODING IS HIGH AND WILL CONTINUE ISLAND WIDE
WITH GOOD CHANCE OF MUDSLIDES OVER MOUNTAINOUS TERRAIN AS SOIL
REMAINS VERY SATURATED AND MOST RIVERS AND STREAMS REMAIN AT OR NEAR
HIGH LEVELS. A WATCH REMAIN IN PLACE FOR ALL OF THE LOCAL ISLANDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  83  71  86  73 / 100  80  80  40
STT  82  71  84  75 / 100  80  80  60

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...FFA  PRZ001>006-012-013 TIL 6 PM.
VI...FFA  VIZ001-002 TIL 6 PM.

&&

MITCHELL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JUAN PR
610 AM AST SUN MAY 23 2004

PRZ001>013-AMZ710>750-241000-
610 AM AST SUN MAY 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO.

.TODAY...MOISTURE MOVING UP FROM SOUTH AMERICA ON THE EAST SIDE OF
AN UPPER TROUGH EXTENDING FROM GUATEMALA TO CUBA WILL BRING MORE
RAIN TO AN ALREADY SOGGY LAND. THIS COUPLED WITH STILL FAVORABLE
UPPER LEVEL WINDS...AND A ZONE OF LOW AND MID LEVEL CONVERGENCE WILL
PROLONG THE CLOUDY SKIES AND PRODUCE COPIOUS RAINS FOR PUERTO RICO.
THE HEAVIEST RAINS WILL DEVELOP IN THE MORNING ALONG THE SOUTH COAST
AND THEN DURING THE DAY OVER THE INTERIOR OF PUERTO RICO  HEAVY
RAINS ARE ALSO DEVELOPING IN THE ATLANTIC WATERS TO OUR NORTH.
WIDESPREAD RAIN WILL CAUSE MANY RIVERS TO RISE...SOME TO FLOOD
STAGE...AND CONSIDERABLE FLOODING OF LOW-LYING AREAS AS WELL AS THE
VERY REAL DANGER OF MUDSLIDES AND TOPPLING TREES. THE HEAVIEST
CONCENTRATION OF RAIN WILL BE AROUND MIDDAY BUT MAY CONTINUE INTO
THE EVENING HOURS.

A MODERATE TO OCCASIONALLY STRONG TRADE WIND FLOW OVER THE REGION
WILL MAINTAIN ROUGH AND CHOPPY SEAS. NORTHEAST SWELL IS ALSO
CONTRIBUTING TO ELEVATED SEAS. THE STRONGEST WINDS AND HIGHEST SEAS
WILL BE IN THE ATLANTIC OFFSHORE WATERS.

.SPOTTER CALL TO ACTION STATEMENT...
SPOTTER ACTIVATION IS REQUESTED.

.DAYS TWO THROUGH SEVEN...

THE VERY MOIST AIR WILL CONTINUE IN THE AREA THROUGH WEDNESDAY EVEN
THOUGH THE DYNAMICS GENERATING THE RAIN WILL BEGIN DECREASING
TONIGHT. THAT SAID...HOWEVER...STRONG CONVECTION WILL CERTAINLY BE
POSSIBLE NEARLY EVERY DAY THIS WEEK IN THE INTERIOR PORTIONS OF
PUERTO RICO AND THE FLOODING OF ROADWAYS...URBAN AREAS...SMALL
STREAMS AND THE RISK OF MUDSLIDES WILL CONTINUE THERE THROUGH AT
LEAST WEDNESDAY. MORE RAIN IS ALSO POSSIBLE OVER EASTERN PUERTO RICO
BY THE END OF THE WEEK.

A MODERATE TO FRESH TRADE WIND FLOW AND CHOPPY SEAS WILL PREVAIL
ACROSS THE LOCAL ISLANDS THROUGH AT LEAST EARLY NEXT WEEK BUT WINDS
AND SEAS WILL BEGIN TO SUBSIDE BY MID TO LATE WEEK.

VIZ001-002-AMZ710>730-241000-
610 AM AST SUN MAY 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS.

.TODAY...MOISTURE MOVING UP FROM SOUTH AMERICA ON THE EAST SIDE OF
AN UPPER TROUGH EXTENDING FROM GUATEMALA TO CUBA WILL BRING MORE
RAIN TO THE VIRGIN ISLANDS. THIS COUPLED WITH STILL FAVORABLE UPPER
LEVEL WINDS...AND A ZONE OF LOW AND MID LEVEL CONVERGENCE PASSING
OVERHEAD FROM THE SOUTH TODAY WILL PROLONG THE CLOUDY SKIES AND
PRODUCE MUCH ABOVE NORMAL RAINFALL. SKIES WILL REMAIN CLOUDY WITH
OCCASIONAL SHOWERS AND RAIN IN THE U.S. VIRGIN ISLANDS. THE HEAVIEST
AND MOST FREQUENT RAIN SHOULD OCCUR IN THE NORTHERN VIRGIN ISLANDS
TODAY. SOME OF THESE STORMS MAY PRODUCE INTERMITTENT HEAVY RAINS
THAT MAY CAUSE LOCALIZED FLOODING OF STREETS AND POOR DRAINAGE
AREAS. TONIGHT RAIN WILL DIMINISH AND THE DANGER OF FLASH FLOODING
WILL DECREASE.

A MODERATE TO OCCASIONALLY STRONG TRADE WIND FLOW OVER THE REGION
WILL MAINTAIN ROUGH AND CHOPPY SEAS. NORTHEAST SWELL IS ALSO
CONTRIBUTING TO ELEVATED SEAS. THE STRONGEST WINDS AND HIGHEST SEAS
WILL BE IN THE ATLANTIC OFFSHORE WATERS.

.SPOTTER CALL TO ACTION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED.

.DAYS TWO THROUGH SEVEN...THE FOCUS OF THE CONVECTIVE ACTIVITY WILL
MOVE NORTH TONIGHT...BUT THE ATMOSPHERE WILL CONTINUE TO BE VERY
MOIST AND SOMEWHAT UNSTABLE. THE VERY MOIST AIR WILL CONTINUE IN THE
AREA THROUGH WEDNESDAY EVEN THOUGH THE DYNAMICS GENERATING THE RAIN
WILL BEGIN DECREASING TONIGHT. PERIODS OF OCCASIONAL MODERATE TO
HEAVY RAINS AT LEAST THROUGH TUESDAY AND AGAIN DURING THE MORNINGS
THURSDAY THROUGH SATURDAY...WILL CAUSE LOCALIZED FLOODING OF STREETS
AND POOR DRAINAGE AREAS.

A MODERATE TO FRESH TRADE WIND FLOW AND CHOPPY SEAS WILL PREVAIL
ACROSS THE LOCAL ISLANDS THROUGH AT LEAST EARLY NEXT WEEK BUT WINDS
AND SEAS WILL BEGIN TO SUBSIDE MIDDLE AND LATE WEEK.

STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER
DETAILS OR UPDATES.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE WEB
SITE FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS AT (ALL LOWERCASE
LETTERS): HTTP://WWW.SRH.NOAA.GOV/SJU.