Small Craft Advisory 31, NWS JSJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
312 PM AST TUE JUL 21 2009

.DISCUSSION...STRONG TROPICAL WAVE AFFECTING AREA TODAY. REPORTS HAVE
COME IN WITH GUSTS UP TO 40 KT OR GREATER WITH THE THUNDERSTORM
ACTIVITY. SATELLITE IMAGES SHOW BROAD CIRCULATION WITH LEADING
EDGE OF WAVE AXIS LIKELY SOUTH OF THE MONA PASSAGE NEARING THE
DOMINICAN REPUBLIC. IMPRESSIVE 0-3 KM HELICITY VALUES OF 150 M/S
WITH VAD WIND PROFILE SHOWING DEEP LAYER 30-50 KT SOUTHEASTERLY
FLOW. BEST CONVERGENT BANDS TRAINED OVER SOUTHEASTERN AND CENTRAL
PR THIS AFTERNOON...NOW HEADING OVER THE NORTHERN COAST PROVOKING
FLASH FLOOD WARNINGS. FLASH FLOOD WATCH WILL REMAIN IN EFFECT
UNTIL AT LEAST 8 THIS EVENING...WITH WIND ADVISORIES AND MARINE
PRODUCTS UNTIL 10 PM.

AS WAVE CONTINUES TO TRACK WEST...RAIN BANDS WILL GO WITH
IT...SPREADING OVER WESTERN PUERTO RICO AND THE MONA CHANNEL...WITH
DECREASING POPS OVER EASTERN HALF OF FORECAST AREA INCLUDING THE
VIRGIN ISLANDS. HAVE NOT HAD ANY TIME TO LOOK AT THE FORECAST AFTER
TONIGHT DUE TO BUSY SHORT TERM OPERATIONS.

&&

.AVIATION...MVFR/IFR CONDITIONS AT ALL SITES EXCEPT USVI AIRPORTS
UNTIL 06Z THIS EVENING...WITH CLEARING FROM EAST TO WEST. SURFACE
WINDS IN THE LOW 20 KNOT RANGE WITH DECENT LOW LEVEL SPEED SHEAR.
EXPECT CONDITIONS TO IMPROVE OVERNIGHT...WITH LIGHT RAIN OVER MOST
SITES AND MOST LIKELY TSRA OVER MONA PASSAGE AREA.

&&

.MARINE...BUOY JUST SOUTH OF PONCE REPORTING MAX SEAS OVER 10 FT
TODAY...WITH SIGNIFICANT WAVE HEIGHTS AROUND 7. UP TO 9 FEET
REPORTED AT BUOY 41403 200 MILES NORTH OF ST THOMAS AS WELL.
SEVERAL GUSTS ABOVE 30 ALSO NOTED ON OBS AND RADAR ESTIMATES. WILL
KEEP MWS OVER ALL CARIBBEAN WATERS UNTIL 10 PM AND SCA FOR ALL
WATERS SAME TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  79  90  81  89 /  60  30  10  20
STT  80  90  81  91 /  50  30  10  20

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...FLASH FLOOD WATCH UNTIL 8 PM AST THIS EVENING FOR CENTRAL
     INTERIOR-EASTERN INTERIOR-MAYAGUEZ AND VICINITY-NORTH
     CENTRAL-NORTHEAST-NORTHWEST-PONCE AND VICINITY-SAN JUAN AND
     VICINITY-SOUTHEAST-SOUTHWEST-WESTERN INTERIOR.

     SMALL CRAFT ADVISORY UNTIL 11 PM AST THIS EVENING FOR CULEBRA.

VI...SMALL CRAFT ADVISORY UNTIL 10 PM AST THIS EVENING FOR ST.
     THOMAS/ST. JOHN/ADJACENT ISLANDS.

&&

09/93

HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN
ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
607 AM AST TUE JUL 21 2009

AMZ710>745-PRZ001>013-221015-
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-
607 AM AST TUE JUL 21 2009

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

.DAY ONE...TODAY AND TONIGHT
THE MOISTURE ASSOCIATED WITH A TROPICAL WAVE JUST ACROSS PUERTO
RICO THIS MORNING WILL CONTINUE TO INDUCE THE DEVELOPMENT OF
FAST MOVING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED TO
SCATTERED THUNDERSTORMS ACROSS PUERTO RICO AND THE COASTAL WATERS
TODAY AND TONIGHT. SOME SHOWERS AND THUNDERSTORMS COULD BE LOCALLY
HEAVY AT TIMES PRODUCING STRONG GUSTY WINDS...ESPECIALLY IN THE
AFTERNOON...AND MAY LEAD TO PONDING OF WATER ON ROADS AND
LOCALIZED FLOODING IN POOR DRAINAGE AREAS. MUDSLIDES ARE ALSO
POSSIBLE IN AREAS OF STEEP TERRAIN.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY
THE LINGERING MOISTURE BEHIND THE TROPICAL WAVE...WILL COMBINE
WITH DAYTIME HEATING AND LOCAL TERRAIN EFFECTS TO INDUCE THE
DEVELOPMENT OF SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS WESTERN AND INTERIOR PUERTO RICO WEDNESDAY
AFTERNOON. SOME SHOWERS COULD BE LOCALLY HEAVY AT TIMES AND MAY
LEAD TO PONDING OF WATER ON ROADS AND MINOR FLOODING IN POOR
DRAINAGE AREAS.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE URGED TO REPORT STRONG WIND OR FLOODING TO
THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN SAN JUAN.

AMZ715-725-VIZ001-002-221015-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
607 AM AST TUE JUL 21 2009

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

.DAY ONE...TODAY AND TONIGHT
THE MOISTURE ASSOCIATED WITH A TROPICAL WAVE JUST ACROSS THE
REGION THIS MORNING WILL CONTINUE TO INDUCE THE DEVELOPMENT OF
FAST MOVING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS
THE LOCAL ISLANDS AND THE SURROUNDING COASTAL WATERS TODAY AND
TONIGHT. SOME SHOWERS AND THUNDERSTORMS COULD BE LOCALLY HEAVY AT
TIMES PRODUCING STRONG GUSTY WINDS...AND MAY LEAD TO PONDING OF
WATER ON ROADS AND SOME MINOR FLOODING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY
THE LINGERING MOISTURE BEHIND THE TROPICAL WAVE...WILL COMBINE
WITH DAYTIME HEATING AND LOCAL ISLANDS EFFECTS TO INDUCE THE
DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS THE SURROUNDING WATERS AND LOCAL ISLANDS ESPECIALLY WEDNESDAY
AFTERNOON.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE URGED TO REPORT STRONG WIND OR FLOODING TO
THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN SAN JUAN.