Special Marine Warning 13, NWS JSJ

418 
FZCA72 TJSJ 112005
MWSSJU

MARINE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
405 PM AST FRI MAY 11 2012

AMZ710-712-112020-
/O.EXP.TJSJ.MA.W.0013.000000T0000Z-120511T2000Z/
405 PM AST FRI MAY 11 2012

...THE SPECIAL MARINE WARNING HAS EXPIRED...

THE AFFECTED AREAS WERE...
COASTAL WATERS OF NORTHERN PUERTO RICO OUT 10 NM OVER ATLANTIC
OFFSHORE WATERS...
ATLANTIC WATERS OF PUERTO RICO AND USVI FROM 10 NM TO 19.5N OVER
ATLANTIC OFFSHORE WATERS...

AT 400 PM AST...DOPPLER WEATHER RADAR INDICATED THAT THE STRONG 
THUNDERSTORM THAT WAS AFFECTING THESE WATERS EARLIER HAD WEAKENED 
AND NO LONGER POSES THE THREAT OF WIND GUSTS TO 34 KNOTS OR GREATER. 
HOWEVER...THIS STORM AND OTHERS ACROSS THE MONA PASSAGE REMAIN 
ACTIVE AND WILL BE MONITORED. FREQUENT CLOUD TO WATER LIGHTNING... 
PERIODS OF HEAVY RAIN...BRIEF GUSTY WINDS AND ROUGH SEAS ARE STILL 
POSSIBLE.  

LAT...LON 1855 6760 1896 6725 1866 6708 1852 6720
TIME...MOT...LOC 1959Z 117DEG 9KT 1867 6733

$$

BCS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1142 AM AST FRI MAY 11 2012

.UPDATE...NO CHANGES WERE MADE TO THE SHORT TERM GRIDS. FORECAST
PACKAGE HAS A PRETTY GOOD HANDLE ON EXPECTED CONDITIONS. SHOWERS
AND THUNDERSTORMS STILL EXPECTED THIS AFTERNOON.

&&

.AVIATION...BRIEF MVFR CONDITIONS ARE EXPECTED IN AND AROUND TJMZ
AND TJBQ IN SHRA/TSRA BTW 11/16Z AND 11/22Z. ELSEWHERE...PREVAILING
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. EAST
SOUTHEAST WINDS AT 10 TO 15 KTS FROM THE SURFACE TO AROUND 10K
FEET...BECOMING WESTERLY AND STRONGER ALOFT.

&&

.PREV DISCUSSION... /ISSUED 522 AM AST FRI MAY 11 2012/

SYNOPSIS...BASED ON THE LATEST WATER VAPOR SATELLITE IMAGERY AND
RECENT UPPER AIR DATA ANALYSIS...AXIS OF WEAKENING UPPER TROUGH NOW
EXTENDS SOUTHWARDS ACROSS PUERTO RICO INTO THE EASTERN CARIBBEAN...
WHILE MID LEVEL SHORT WAVE TROUGH EXTENDS ACROSS HISPANIOLA INTO
THE EAST CENTRAL CARIBBEAN. THESE FEATURES ALTHOUGH EXPECTED TO
CONTINUE TO WEAKEN ACROSS THE REGION TODAY WILL HELP MAINTAIN UNSTABLE
CONDITIONS ACROSS THE REGION AT LEAST FOR ANOTHER DAY OR SO. MEANWHILE
STRONG SURFACE HIGH PRESSURE EXTENDING FURTHER SOUTHWEST INTO THE
NORTHEAST CARIBBEAN WILL MAINTAIN A LIGHT BUT MOIST SOUTHEASTERLY
TRADE WIND FLOW ACROSS THE REGION TODAY. WINDS ARE EXPECTED TO GRADUALLY
BECOME MORE EASTERLY BY THE UPCOMING WEEKEND...AS ANOTHER AREA OF HIGH
PRESSURE REESTABLISHES ACROSS THE WESTERN ATLANTIC AND BUILDS NORTH
OF THE FORECAST AREA.

DISCUSSION...FAVORABLE MID TO UPPER LEVEL CONDITIONS AND FAIRLY
MOIST LOW LEVEL AIR MASS...WILL COMBINE WITH DIURNAL EFFECTS AND
LOCAL FORCING TO PRODUCE MOSTLY ISOLATED TO SCATTERED CONVECTION
ACROSS PARTS OF THE ISLANDS TODAY. SOIL REMAIN FAIRLY SATURATED
ACROSS MUCH OF THE ISLAND...SO EXPECT CONVECTIVE DEVELOPMENT LATER
IN THE AFTERNOON...WITH THE MOST ENHANCED SHOWERS AND THUNDERSTORM
ACTIVITY TO BE FOCUSED ACROSS PARTS OF THE NORTH CENTRAL AND NORTHWEST
SECTIONS OF PUERTO RICO. DUE TO THE UNSTABLE CONDITIONS... EXPECT
PERIODS OF LOCALLY HEAVY RAINFALL IN SOME AREAS...AND THIS MAY
ONCE AGAIN RESULT IN URBAN AND FLASH FLOODING TODAY...ESPECIALLY
ACROSS PARTS OF PUERTO RICO. THE POTENTIAL FOR MUDSLIDES WILL ALSO
REMAIN HIGH ESPECIALLY IN AREAS OF STEEP TERRAIN OVER PUERTO RICO.

ON SATURDAY CONTINUED GRADUAL IMPROVEMENT IS FORECAST...HOWEVER EXPECT
SUFFICIENT MOISTURE ACROSS THE ISLANDS FOR LOCALLY AND DIURNALLY INDUCED
AFTERNOON CONVECTION. THE FORMATION AND LOCATION OF THE SHOWER ACTIVITY
WILL BE DEPENDENT ON THE LOCAL STEERING WINDS...WHICH WILL BE MAINLY
FROM THE SOUTHEAST...THEN BECOMING MORE EASTERLY BY LATE SATURDAY
AFTERNOON. EVEN DRIER CONDITIONS EXPECTED ON SUNDAY... AS THE EASTERLY
TRADE WINDS WILL INCREASE IN RESPONSE TO HIGH PRESSURE RIDGE BUILDING
SOUTHWARDS ACROSS THE NORTHEAST CARIBBEAN FROM THE WEST AND SOUTHWEST
ATLANTIC. IN ADDITION...EARLIER SATELLITE IMAGERY AS WELL AS THE
NAVY GLOBAL AEROSOL FORECAST MODEL SHOWED A SURGE OF SAHARAN DUST
JUST EAST OF THE LESSER ANTILLES WITH LEADING EDGE NOW NEAR 57
WEST. ALL MODELS CONSISTENT IN BRINGING THIS DRIER AIR/SAL ACROSS
THE EASTERN CARIBBEAN BY LATE SATURDAY INTO SUNDAY... WITH A LOW
LEVEL WIND SURGE BETWEEN 20 TO 25 KNOTS EXPECTED TO MOVE WELL
SOUTH OF THE REGION BY EARLY SUNDAY. THEREFORE...WILL CONTINUE TO
MONITOR TO SEE HOW THIS SCENARIO UNFOLDS.

AVIATION...MOSTLY VFR CONDITIONS...WITH BRIEF PERIODS OF MVFR
CONDITIONS ARE EXPECTED ACROSS THE LOCAL TERMINALS FOR THE REST OF
THE MORNING HOURS OR UNTIL 11/16Z. HOWEVER...ABUNDANT CLOUDINESS
ACROSS THE AREA...WILL PROMOTE PERIODS OF MVFR CEILINGS MAINLY
ACROSS TNCM AND TKPK. BRIEF PASSING SHOWERS ARE POSSIBLE THIS
MORNING IN AND AROUND TIST...TISX... TNCM...TKPK...AND TJSJ. THEN
AFT 11/16Z SHWRS AND TSTMS WILL DEVELOP IN NW PR WITH AREAS OF MVFR
CONDS AND MTN OBSCURATIONS. TJSJ 11/00Z SOUNDING INDICATED A LIGHT
EAST SOUTHEAST WIND FLOW FROM THE SURFACE TO AROUND 10K
FEET...BECOMING WESTERLY AND STRONGER ALOFT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  86  77  88  77 /  30  20  30  20
STT  86  77  86  78 /  30  30  20  20

&&

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

23/25

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JUAN PR
604 AM AST FRI MAY 11 2012

AMZ710>745-PRZ001>013-121015-
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-
604 AM AST FRI MAY 11 2012

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

.DAY ONE...TODAY AND TONIGHT

THE INSTABILITY ACROSS THE REGION IN COMBINATION WITH DAYTIME
HEATING AND LOCAL ISLANDS EFFECTS WILL INDUCE THE DEVELOPMENT OF
SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR...WESTERN AND
NORTHWEST PUERTO RICO THIS AFTERNOON AND EVENING. PERIODS OF HEAVY
RAINFALL AND SOME FLOODING ARE EXPECTED...WITH THE POTENTIAL FOR
FLASH AND RIVER FLOODING AS WELL AS MUDSLIDES IN AREAS OF STEEP
TERRAIN.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THE INSTABILITY ACROSS THE REGION IN COMBINATION WITH DAYTIME
HEATING AND LOCAL ISLANDS EFFECTS WILL INDUCE THE DEVELOPMENT OF
SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR...WESTERN AND
INTERIOR PUERTO RICO EACH AFTERNOON AND EVENING. PERIODS OF HEAVY
RAINFALL AND SOME FLOODING ARE EXPECTED.

.SPOTTER INFORMATION STATEMENT...

ANY REPORTS OF RAINFALL GREATER THAN THREE INCHES OR FLASH
FLOODING WOULD BE GREATLY APPRECIATED.

AMZ715-725-VIZ001-002-121015-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
604 AM AST FRI MAY 11 2012

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...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.