000
AGXX40 KNHC 251933
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
300 PM EDT MON MAY 25 2009

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA 
AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W.

GULF OF MEXICO...
WINDS REMAIN LIGHT OUT OF THE S-SW OVER MUCH OF THE AREA AS A 
WEAK PRESSURE GRADIENT REMAINS IN PLACE TO THE SOUTH OF LOW 
PRESSURE CENTERED NEAR SW MISSOURI. A TRAILING SFC TROUGH THAT 
EXTENDS INTO THE NW WATERS FROM SE LOUISIANA TO NEAR CORPUS 
CHRISTI IS TRIGGERING NUMEROUS SHOWERS AND TSTMS WITHIN 90 NM 
OF THE TROUGH LINE. SLY WINDS ARE EXPECTED TO INCREASE TO 15-20 
KT OVER THE FAR W WATERS TUE AS TROUGHING BECOMES MORE 
PRONOUNCED OVER TEXAS/MEXICO AND RIDGING BUILDS W OVER THE SE 
GULF. BY LATE WED...AN ASSOCIATED COLD FRONT IS EXPECTED TO 
APPROACH THE NW WATERS. SEVERAL OF THE NUMERICAL MODELS DEVELOP 
LOWS ALONG THE FRONT BUT ARE IN DISAGREEMENT ON THE LOCATION AND 
TIMING. MODELS ARE IN GENERAL AGREEMENT IN SHOWING THE FRONT 
PUSH S TO THE FAR N WATERS OR REMAIN JUST INLAND ALONG THE N 
GULF COAST WED NIGHT THROUGH FRI. DECIDED TO INCREASE SW WINDS A 
NOTCH TO 15-20 KT ACROSS THE N WATERS DUE TO THE PROXIMITY OF 
THE BOUNDARY. THIS FORECAST IS LOWER THAN THE GFS AND IN CLOSEST 
AGREEMENT WITH THE ECMWF.

CARIBBEAN AND TROPICAL ATLC W OF 55W...
PRESSURE GRADIENT BETWEEN HIGH PRES E OF BERMUDA NEAR 33N59W 
AND LOWER PRESSURE OVER SOUTH AMERICA IS CONTINUING TO PRODUCE A 
SWATH OF 20-25 KT E TO SE TRADE WINDS OVER THE SE CARIBBEAN. E 
TO SE 15-20 KT WINDS ARE PRESENT ACROSS MUCH OF THE REMAINDER OF 
THE EASTERN AND CENTRAL CARIBBEAN AND E OF THE WINDWARDS. 
ELSEWHERE IN THE WESTERN CARIBBEAN AND OVER ATLC WATERS N OF 15N 
BETWEEN 55W AND THE ISLANDS...TROUGHS TO THE NORTH OF THESE 
RESPECTIVE AREAS ARE MAINTAINING ONLY 10-15 KT FLOW. A LOW 
AMPLITUDE FAST MOVING TROPICAL WAVE ALONG 61W WILL SHIFT INTO 
THE EASTERN CARIBBEAN TONIGHT PERHAPS ENHANCING WINDS A TAD. 
WINDS WILL INCREASE FURTHER E OF THE WINDWARDS BY THE END OF THE 
WEEK AS THE TROUGHING TO THE NORTH BREAKS DOWN AND THE ATLC 
RIDGE BUILDS SW. SIMILARLY...WINDS WILL PICK UP OVER THE NW 
CARIBBEAN TUE NIGHT AND WED AS A RIDGE BUILDS OVER THE GULF OF 
MEXICO. WINDS ARE EXPECTED TO REMAIN STRONGEST OVER THE 
SOUTHEAST AND SOUTH CENTRAL CARIBBEAN THROUGH THE WEEK WITH SEAS 
BUILDING TO 8-10 FT IN E SWELL BY THE END OF THE WEEK.

SUBTROPICAL ATLANTIC W OF 55W...
VISIBLE SATELLITE IMAGERY REVEALS AN IMPROVED AREA OF CYCLONIC 
TURNING JUST E OF THE BAHAMAS CENTERED NEAR 24N74W. HOWEVER... 
THIS ROTATION APPEARS LIKELY OFF THE SFC BASED ON BAHAMA 
OBSERVATIONS. A QUIKSCAT PASS FROM AROUND 11Z CONFIRMED THE 
FORMATION OF A TROUGH AT THE SFC WITH AN AREA OF 15-20 KT SE 
WINDS WITHIN 240 NM E OF THE BAHAMA CHAIN. WINDS COULD BE 
HIGHER...BUT IT IS DIFFICULT TO DETERMINE DUE TO RAIN 
CONTAMINATION. GFS REMAINS VERY AGGRESSIVE IN SHOWING A CLOSED 
SFC LOW FORM AND QUICKLY INTENSIFY AS IT TRACKS N-NE WITH WINDS 
INCREASING TO 30-40 KT AROUND THE LOW CENTER BY TUE AND WED. THE 
OTHER GLOBAL MODELS ARE MUCH LESS AGGRESSIVE AND THE UKMET 
CONTINUES TO SHOW ONLY A WEAK E-W TROUGH DRIFT NWD. AFTER 
COORDINATION WITH THE OCEAN PREDICTION CENTER...WE HAVE DECIDED 
TO MORE OR LESS GO IN BETWEEN SCENARIOS YIELDING THE DEVELOPMENT 
OF A WEAK SFC LOW ALONG AN ELONGATED E-W TROUGH THAT TRACKS NWD. 
WILL LIKELY INCREASE WINDS TO 25 KT ON THE NE SIDE OF THE 
TROUGH/LOW TONIGHT THROUGH TUE NIGHT. THE LOW MOVES N OF THE 
AREA BY TUE NIGHT. HIGH PRES RIDGING WILL BUILD W IN THE WAKE OF 
THE TROUGH WED THROUGH FRI.        

WARNINGS

ATLC...
.NONE.

CARIBBEAN...
.NONE.

GULF OF MEXICO...
.NONE.

FORECASTER CANGIALOSI. TROPICAL PREDICTION CENTER.