Flash Flood Warning 16, NWS JSJ

431 
WGCA72 TJSJ 151941
FFSSJU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
341 PM AST WED MAY 15 2013

PRC029-077-085-103-119-151949-
/O.EXP.TJSJ.FF.W.0016.000000T0000Z-130515T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CANOVANAS PR-NAGUABO PR-JUNCOS PR-LAS PIEDRAS PR-RIO GRANDE PR-
341 PM AST WED MAY 15 2013

...THE FLASH FLOOD WARNING WILL EXPIRE AT 345 PM AST FOR RIO
GRANDE...LAS PIEDRAS...JUNCOS...NAGUABO AND CANOVANAS
MUNICIPALITIES...

DOPPLER RADAR INDICATED THAT THE HEAVY RAIN WHICH AFFECTED THIS AREA 
HAD WEAKENED. ONLY LIMITED AMOUNTS OF ADDITIONAL RAINFALL ARE 
EXPECTED ACROSS THESE AREAS AT THIS TIME. AN URBAN AND SMALL STREAM 
FLOOD ADVISORY WILL CONTINUE UNTIL AT LEAST 4:30 PM AST ACROSS THE 
WARNED AREA.

LAT...LON 1831 6587 1831 6580 1823 6577 1822 6588

$$

SNELL

ADDITIONAL INFORMATION CAN BE FOUND AT /USE LOWER CASE LETTERS/:
     HTTP://WWW.WEATHER.GOV/SANJUAN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1203 PM AST WED MAY 15 2013

.UPDATE...CONSISTENT WITH THE CURRENT FORECAST...SHOWERS HAVE
DEVELOPED ACROSS MOST OF PUERTO RICO AND A FEW THUNDERSTORMS ARE
EXPECTED LATER IN THE DAY. SATELLITE IMAGES INDICATE THAT THE
CLOUDINESS HAS INCREASED CONSIDERABLY THROUGH THE DAY ACROSS THE
AREA. EVEN THOUGH THE 15/12Z SOUNDING REPORTED A PRECIPITABLE
WATER VALUE OF 1.6 INCHES...THE AVAILABLE MOISTURE IS EXPECTED TO
INCREASE THROUGH THE DAY.

NO CHANGES WERE MADE TO THE FORECAST PACKAGE AS WE STILL
EXPECT SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR PUERTO RICO. THE
U.S. VIRGIN ISLANDS SHOULD EXPECT ISOLATED TO LOCALLY SCATTERED
SHOWERS.

&&

.AVIATION...MVFR/IFR CONDITIONS ARE POSSIBLE TODAY ACROSS THE
TERMINALS IN PR DUE TO DEVELOPING SHRA/TSRA THIS AFTERNOON. WINDS
WILL BE MAINLY FROM THE EAST SOUTHEAST WITH SEA BREEZE VARIATIONS.
WEATHER CONDITIONS EXPECTED TO IMPROVE AFTER 16/00Z...LEAVING
SCATTERED CLOUDS AND WINDS FROM THE EAST AT 10 KTS OR LESS.

&&

.MARINE...NO CHANGES FROM THE PREVIOUS DISCUSSION.

&&

.PREV DISCUSSION... /ISSUED 424 AM AST WED MAY 15 2013/

SYNOPSIS...UPPER LEVEL TROF OVR THE WRN ATLC EAST OF 70W WILL
SWING BY NORTH OF THE AREA TODAY. WEAK MID LEVEL HIGH PRES WILL
BUILD OVR THE AREA LATE THU AND FRI. ANOTHER TROF WILL IMPACT THE
AREA EARLY NEXT WEEK.

DISCUSSION...MODEL TRENDS SINCE YESTERDAY SHOW A WEAKER TROF
PASSING NORTH OF THE AREA TODAY WITH BEST FORCING STAYING NORTH OF
19.5N. AS A RESULT...GUIDANCE IS NOW SHOWING LESS PRECIP FOR TODAY
THAN YDAY. HOWEVER...ANY SHOWERS THAT DO FORM WILL BE VERY SLOW
MOVERS DUE TO VERY WEAK OR ILL-DEFINED STEERING CURRENTS WITH THE
POTENTIAL TO PRODUCE LOCALIZED HEAVY RAINFALL AND ISOLD FLASH
FLOODING. MID LEVEL HIGH PRES BUILDS OVER THE AREA BY FRI WITH
MODELS SHOWING SIG DRYING FRI THROUGH SAT.

LATE SAT NIGHT THRU MID NEXT WEEK...MODELS SHOW MID LEVEL HIGH
PRES DISSIPATING AS ANOTHER TROF MOVES INTO THE BAHAMAS. THIS WILL
PROMOTE MOISTURE TRANSPORT AND ENHANCE CONVECTIVE INSTABILITY WITH
AN INCREASE IN AREAL COVERAGE OF SHOWERS EXPECTED SUN AND INTO
EARLY NEXT WEEK. BY TUE AND WED...MOISTURE BECOMES VERY DEEP WITH
PW VALUES WELL OVER 2.0 INCHES AS TRADE WIND CONVERGENCE INCREASES
OVR THE ISLAND. TIMING DIFFERENCES BECOME MORE EVIDENT NEXT WEEK
WITH GFS BEING FASTER THAN ECMWF IN BRINGING A DEEP SURGE IN
MOISTURE BUT OVERALL TREND SHOULD BE FOR VERY WET WEATHER MID TO
LATE NEXT WEEK AS EQUATORIAL TROUGH LIFTS NORTHWARD.

AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES UNTIL
15/12Z. HOWEVER...ISOLATED PASSING SHRA WILL MOVE WEST ACROSS THE
COASTAL WATERS BETWEEN PR AND THE LESSER ANTILLES. THIS WILL RESULT
IN BRIEF MOUNTAIN OBSCURATIONS OVER EASTERN PR WITH PERIODS OF MVFR
CONDITIONS DUE TO THE PASSING LOW CLDS AND SHRA. AFTERNOON SHRA/TSRA
ARE EXPECTED OVER THE INTERIOR AND NORTH SECTIONS OF PR...AFFECTING
MAINLY TJMZ...TJBQ AND TJSJ FROM 15/18-23Z. WINDS WILL BE FROM THE
EAST TO SOUTHEAST AT 5-15 KTS UP TO 2 KFT THROUGH THE FCST PERIOD.

MARINE...SEAS 2-4 FT INCREASING 5-6 FT OVR THE WEEKEN ON
NORTHEAST SWELLS. TSTMS WILL BE THE MAIN WX HAZARD.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  87  77  86  77 /  20  20  40  10
STT  86  79  87  79 /  20  20  20  20

&&

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

25/71

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JUAN PR
641 AM AST WED MAY 15 2013

AMZ710>745-PRZ001>013-161045-
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-
641 AM AST WED MAY 15 2013

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

.DAY ONE...TODAY AND TONIGHT
UPPER LEVEL TROUGH OVER THE WESTERN ATLANTIC WILL MOVE ACROSS THE
AREA LATER TODAY AND TRIGGER AFTERNOON SHOWERS AND THUNDERSTORMS.
THUNDERSTORMS WILL BE VERY SLOW MOVERS AND BE CAPABLE OF PRODUCING
LOCALIZED HEAVY RAINFALL AND ISOLATED FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER REPORTS OF TWO INCHES OR MORE AND ANY FLOODING WOULD BE
GREATLY APPRECIATED.

AMZ715-725-VIZ001-002-161045-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
641 AM AST WED MAY 15 2013

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

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.