Flash Flood Warning 19, NWS JSJ

000 
WGCA72 TJSJ 232033
FFSSJU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
427 PM AST FRI MAY 23 2008

PRC021-061-232037-
/O.EXP.TJSJ.FF.W.0019.000000T0000Z-080523T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BAYAMON PR-GUAYNABO PR-
427 PM AST FRI MAY 23 2008

...THE FLASH FLOOD WARNING WILL EXPIRE AT 430 PM AST FOR GUAYNABO AND
BAYAMON MUNICIPALITIES...

VERY HEAVY RAIN IS CONTINUING IN THE AREA FROM TORTUGO TO PAJAROS 
ACROSS SAN JUAN...BAYAMON AND GUAYNABO. AN URBAN AND SMALL STREAM 
ADVISORY REMAINS IN EFFECT FOR THESE AREAS. PERSONS IN THESE AREAS 
SHOULD UNDERSTAND THAT THERE ARE SOME AREAS WHERE WATER COVERS 
ROADS...MAKING THEM IMPASSIBLE. RAIN IS EXPECTED TO DISSIPATE BY 8 
PM AST.

LAT...LON 1841 6610 1838 6611 1839 6618 1841 6617
TIME...MOT...LOC 2027Z 081DEG 18KT 1834 6618

$$

SNELL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1123 AM AST FRI MAY 23 2008

.UPDATE...SCATTERED SHOWERS BEGAN TO DEVELOP ACROSS SAN JUAN AND
VICINITY LATE THIS MORNING...AND THIS SHOWER ACTIVITY WILL
CONTINUE TO PROPAGATE ACROSS THE ISLANDS LATER THIS AFTERNOON
MAINLY ACROSS THE WESTERN HALF OF PUERTO RICO. MADE MINOR CHANGES
TO THE TEMPERATURES THROUGH DAY 5. NO OTHER CHANGES WERE MADE.

.AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL
ISLANDS AND AT ALL LOCAL TAF SITES FOR THE REST OF TODAY.
HOWEVER...MVFR OR POSSIBLY EVEN BRIEF IFR CONDITIONS...AND LOCAL
MOUNTAIN OBSCURATIONS...WILL BE POSSIBLE THIS AFTERNOON FROM 17Z-
22Z...ESPECIALLY ACROSS TJBQ...TJMZ AND TJSJ.

&&

.PREV DISCUSSION... /ISSUED 527 AM AST FRI MAY 23 2008/

SYNOPSIS...
MID TO UPPER LEVEL HIGH PRESSURE RIDGE EXTENDED FROM THE WESTERN
CARIBBEAN NORTHWARDS ACROSS THE GREATER ANTILLES THEN INTO THE
CENTRAL ATLANTIC. THIS SEPARATES AN UPPER TROUGH ACROSS THE
NORTHWEST ATLANTIC...AND ANOTHER ACROSS THE EAST ATLANTIC WHICH
EXTENDS SOUTHWARDS ACROSS THE TROPICAL ATLANTIC. SURFACE HIGH
PRESSURE RIDGE EXTENDED FROM THE CENTRAL ATLANTIC WEST SOUTHWEST
THROUGH THE BAHAMAS...AND WILL GRADUALLY WEAKEN ACROSS THE AREA
INTO THE WEEKEND. THE AREA OF HIGH PRESSURE CENTERED ACROSS THE
CENTRAL ATLANTIC WILL SHIFT FURTHER EASTWARD...AS A COLD FRONTAL
SYSTEM EXITS THE EASTERN UNITED STATES AND MOVES ACROSS THE
WESTERN ATLANTIC SATURDAY THROUGH SUNDAY. IN THE MEANTIME...A WEAK
LOW LEVEL DISTURBANCE IN THE PREVAILING EASTERLIES WILL CONTINUE
WESTWARDS ACROSS THE EASTERN CARIBBEAN TODAY THROUGH SATURDAY
MORNING.

DISCUSSION...
DOMINANT ATLANTIC HIGH PRESSURE WILL MAINTAIN A MODERATE TRADE
WIND FLOW ACROSS THE REGION AT LEAST THROUGH SATURDAY...THEN
GRADUALLY WEAKEN AS THE UPPER LEVEL TROUGH DEEPENS ACROSS THE WEST
ATLANTIC...AND MOVES ACROSS HISPANIOLA ON SUNDAY...THEN APPROACHES
THE LOCAL AREA BY MONDAY. THE RECEDING ATLANTIC HIGH AND THE APPROACHING
UPPER LEVEL LONG WAVE TROUGH WILL INDUCE LOW LEVEL TROUGHINESS ACROSS
THE LOCAL REGION...AND THEREFORE INCREASE THE CHANCES FOR EVEN MORE
ACTIVE WEATHER ACROSS THE AREA BY EARLY NEXT WEEK. IN ADDITION...
LATEST GFS MODEL GUIDANCE CONTINUE TO SUGGEST A TROPICAL WAVE TO
AFFECT THE LOCAL AREA MONDAY THROUGH TUESDAY...FOLLOWED BY YET ANOTHER
DURING THE LATTER PART OF THE NEXT WEEK. SO FOR THE WEEKEND...EXPECT
PASSING CLOUDS AND TRADE WIND SHOWERS TO AFFECT THE EAST COASTAL AREAS
DURING THE MORNING HOURS...FOLLOWED BY DIURNAL AND LOCAL TERRAIN INDUCED
SHOWER ACTIVITY DURING THE AFTERNOON HOURS. BY EARLY NEXT WEEK
MORE ACTIVE WEATHER IS EXPECTED DUE TO THE PROXIMITY OF THE UPPER
LEVEL TROUGH AND THE APPROACHING TROPICAL WAVES. AS USUAL...WILL
HOWEVER CONTINUE TO MONITOR AND MAKE NECESSARY ADJUSTMENTS TO THE
FORECAST PACKAGE WITH TIME.

AVIATION...
EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL ISLANDS AND AT
ALL LOCAL TAF SITES THIS MORNING. HOWEVER...MVFR OR POSSIBLY EVEN
BRIEF IFR CONDITIONS...AND LOCAL MOUNTAIN OBSCURATIONS...WILL BE
POSSIBLE THIS AFTERNOON FROM 17Z-22Z...ESPECIALLY ACROSS TJBQ...TJMZ
AND TJSJ.

PATCHY LOW LEVEL MOISTURE AND SHOWERS MAY AFFECT THE TIST AND TISX
EARLY THIS AFTERNOON THROUGH THE EVENING HOURS FROM TIME TO TIME AS
THESE CLOUDS AND SHOWERS MOVE ACROSS THE ISLANDS WITH THE HELP OF
THE TRADE WINDS WHICH WILL BE AVERAGING FROM 10 TO 15 KNOTS.

MARINE...
FAIRLY TRANQUIL MARINE CONDITIONS ARE EXPECTED TO CONTINUE ACROSS
THE REGIONAL WATERS THROUGH SATURDAY EXCEPT FOR SOME PERIODS OF
LOCALLY HEAVY RAINFALL ASSOCIATED WITH ISOLATED TO SCATTERED
SHOWER ACTIVITY. GENERALLY EXPECT WINDS OF 16 KNOTS OR LESS AND
SEAS OF 4 FEET OR LESS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  86  75  87  75 /  20  10  30  20
STT  85  75  85  75 /  40  40  40  40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&

71/06

HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN
ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
629 AM AST FRI MAY 23 2008

AMZ710>750-PRZ001>013-241030-
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-
629 AM AST FRI MAY 23 2008

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

.DAY ONE...TODAY AND TONIGHT

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SUNDAY INTO MONDAY AND EVEN FURTHER...AN UPPER LEVEL TROUGH IS FORECAST
TO EXIT THE EASTERN SEABOARD OF THE UNITED STATES AND DIG
SOUTHEASTWARD ACROSS THE SOUTH WESTERN ATLANTIC. FROM MONDAY
AFTERNOON THROUGH AT LEAST MID WEEK...WE WILL BE UNDER THE
INFLUENCE OF THIS UPPER LEVEL TROUGH WHICH WILL HELP TO
DESTABILIZE THE ATMOSPHERE...CREATING FAVORABLE CONDITIONS ALOFT FOR
ACTIVE WEATHER DAYS DURING THE UPCOMING WEEK. ALSO...A WEAK TROPICAL
WAVE IS FORECAST TO MOVE ACROSS THE LOCAL AREA BY THE SECOND HALF OF
THE UPCOMING WEEKEND...YET ANOTHER TROPICAL WAVE...EXPECTED TO ARRIVE
THE LOCAL AREA BY THURSDAY. THIS CAN BE TRANSLATED TO POSSIBLE
MODERATE TO HEAVY SHOWER ACTIVITY WITH THUNDERSTORMS OVER LAND
AREAS AND ACROSS THE LOCAL COASTAL WATERS. WE WILL KEEP MONITORING
THIS SCENARIO AS THE WEEKEND PROGRESSES AS WELL AS ADJUSTING THE
WEATHER FORECAST ACCORDINGLY TO MAINTAIN THE PUBLIC INFORM AT ALL
TIMES.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED AT THIS TIME.

AMZ720-730-VIZ001-002-241030-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
629 AM AST FRI MAY 23 2008

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

.DAY ONE...TODAY AND TONIGHT

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SUNDAY INTO MONDAY AND EVEN FURTHER...AN UPPER LEVEL TROUGH IS FORECAST
TO EXIT THE EASTERN SEABOARD OF THE UNITED STATES AND DIG
SOUTHEASTWARD ACROSS THE SOUTH WESTERN ATLANTIC. FROM MONDAY
AFTERNOON THROUGH AT LEAST MID WEEK...WE WILL BE UNDER THE
INFLUENCE OF THIS UPPER LEVEL TROUGH WHICH WILL HELP TO
DESTABILIZE THE ATMOSPHERE...CREATING FAVORABLE CONDITIONS ALOFT FOR
ACTIVE WEATHER DAYS DURING THE UPCOMING WEEK. ALSO...A WEAK TROPICAL
WAVE IS FORECAST TO MOVE ACROSS THE LOCAL AREA BY THE SECOND HALF OF
THE UPCOMING WEEKEND...YET ANOTHER TROPICAL WAVE...EXPECTED TO ARRIVE
THE LOCAL AREA BY THURSDAY. THIS CAN BE TRANSLATED TO POSSIBLE
MODERATE TO HEAVY SHOWER ACTIVITY WITH THUNDERSTORMS OVER LAND
AREAS AND ACROSS THE LOCAL COASTAL WATERS. WE WILL KEEP MONITORING
THIS SCENARIO AS THE WEEKEND PROGRESSES AS WELL AS ADJUSTING THE
WEATHER FORECAST ACCORDINGLY TO MAINTAIN THE PUBLIC INFORM AT ALL
TIMES.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED AT THIS TIME.