Marine Weather Discussion

000
AGXX40 KNHC 161723
MIMATS

MARINE WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
125 PM EDT TUE SEP 16 2008

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

GULF OF MEXICO...
A WEAK...EARLY SEASON COLD FRONT HAS SLIPPED INTO THE GULF OF 
MEXICO AND EXTENDS ROUGHLY FROM THE APALACHEE BAY THROUGH WEAK 
LOW PRESSURE AT 27N92W TO 19N95W. BUOY REPORTS AND A 1246 UTC 
QUIKSCAT PASS INDICATE THAT N TO NE 15 TO 20 KT ARE OCCURRING W 
OF THE FRONT W OF 91W...WITH THE STRONGEST WINDS OF UP TO 25 KT 
S OF 25N W OF 95W. SEAS RANGE FROM 4 TO 6 FT N OF 25N W OF 91W 
EXCEPT FOR 3 TO 4 FT ALONG THE IMMEDIATE TX COAST BUT HAVE BUILT 
TO 5 TO 8 FT S OF 25N W OF FRONT. E OF 91W W OF FRONT NE WINDS 
ARE BLOWING 10 TO 15 KT WITH SEAS OF 2 TO 4 FT. SATELLITE 
PICTURES SHOW CONTINUED CONVECTIVE DEVELOPMENT ALONG THE 
BOUNDARY BOTH OFFSHORE THE LOUISIANA COAST AND OFFSHORE THE NE 
MEXICAN COAST FROM LA PESCA TO NEAR VERA CRUZ...BUT THIS SHOULD 
BEGIN TO DECREASE LATER TONIGHT AND WED. OTHERWISE...A GENTLE NE 
TO E WIND FLOW PREVAILS AHEAD OF THE FRONT ALONG WITH SEAS OF 2 
FT OR LESS.

AS THE UPPER-LEVEL SUPPORT FOR THE FRONT LIFTS NE AND AWAY FROM 
THE AREA...THE FRONT SHOULD STALL WED AND GRADUALLY BECOME ILL- 
DEFINED. AS THIS OCCURS...THE 20 KT N TO NE FLOW W OF THE FRONT 
SHOULD ONLY SLOWLY ABATE...WITH STILL INTERMITTENT 20 KT WINDS 
POSSIBLE THROUGHOUT THE DAY WED. WITH WINDS COMING DOWN...EXPECT 
SEAS TO BEGIN SUBSIDING TOO. NOAA WAVEWATCH III INDICATES 3 TO 5 
FT SEAS OVER THE NW GULF W OF THE FRONT BY WED NIGHT...STILL 4 
TO 7 FT W OF THE FRONT OVER THE SW ZONE...AND 2 FT OR LESS SEAS 
N OF THE FRONT OVER THE MIDDLE GULF ZONE. ALTHOUGH THE FRONT 
WILL HAVE DISSIPATED...WEAK LOW PRESSURE IS FORECAST OVER THE NW 
GULF SHOULD PERSIST THU AND FRI EVEN THOUGH THE FRONT WILL HAVE 
DISSIPATED...BUT IT TOO SHOULD UNWIND BY SAT.

BY LATE FRI AND INTO THE WEEKEND...MODELS SHOW A SECOND SURGE 
COMING DOWN THE EAST COAST WHICH SHOULD BRING ANOTHER WEAK 
BOUNDARY INTO THE FAR NORTHERN WATERS. BEHIND THE BOUNDARY...NE 
TO E WINDS SHOULD AVERAGE 10 TO 15 KT AND SEAS SHOULD RANGE 
BETWEEN 2 AND 4 FT. OTHERWISE...A CONTINUED GENTLE NE TO E FLOW 
SHOULD PREVAIL OVER THE REMAINDER OF THE GULF EXCEPT FOR N TO NE 
OVER THE WESTERN GULF.

CARIBBEAN AND TROPICAL ATLC...
AN ACTIVE TROPICAL WAVE OVER THE FAR WESTERN CARIBBEAN IS ON ITS 
WAY OUT BUT IS STILL CREATING RELATIVELY UNSETTLED CONDITIONS 
OVER PARTS OF THE SW CARIBBEAN AS WELL AS THE GULF OF HONDURAS. 
SATELLITE PICTURES CONFIRM THIS...INDICATING SCATTERED TO 
LOCALLY NUMEROUS TSTMS OVER THESE AREAS WITH LOCALLY HIGHER 
WINDS AND SEAS. MODELS STILL INSIST ON A BROAD AREA OF LOW 
PRESSURE FORMING EITHER OVER OR W OF CENTRAL AMERICA THE NEXT 
FEW DAYS AND SLOWLY DRIFTING W TO NW. HOWEVER...MANY MORE OF THE 
MODEL RUNS ARE SUGGESTING THAT ANY LOW PRESSURE TO FORM WOULD DO 
SO IN THE EASTERN PACIFIC S OF CENTRAL AMERICA. WHETHER OR NOT 
LOW PRESSURE EVOLVES OR NOT...THE LARGE-SCALE GRADIENT EXPECTED 
TO REMAIN WEAK. THUS LITTLE TO NO INCREASE IN WINDS AND SEAS ARE 
NOTED IN THE NW AND SW CARIBBEAN ZONES LATER THIS WEEK...THOUGH 
A MENTION OF SCATTERED TSTMS HAS BEEN INSERTED.

ELSEWHERE...AN 1104 UTC QUIKSCAT PASS CONFIRMS E WINDS TO 20 KT 
OVER THE S CENTRAL WATERS...FROM 11N TO 15N BETWEEN 68W AND 78W. 
SEAS ARE ESTIMATED TO BE BETWEEN 4 AND 7 FT OVER THIS AREA... 
THOUGH UP TO 8 FT SEAS ARE POSSIBLE OFF THE COAST OF COLOMBIA. 
MODEL GUIDANCE SHOWS THESE WINDS CONTINUING INTO WED BUT THEN 
DECREASING HERE AND BASIN WIDE INTO THE WEEKEND. IN FACT...A 
GENTLE TO MODERATE NE TO E FLOW IS EXPECTED ALL AREAS. WITH SEAS 
RANGING FROM 2 TO 4 FT OVER THE NW AND 3 TO 5 FT ELSEWHERE.

FINALLY...A MORNING QUIKSCAT PASS CONTINUED TO SHOW LOCALLY 
STRONG WINDS W OF A WEAKENING TROPICAL WAVE NOW ALONG 60W FROM 
ABOUT 16N TO 22N. IN FACT...E TO SE WINDS OF 20 KT WERE NOTED 
WITHIN 360 NM E OF THE WAVE AXIS. A SWATH OF MODERATE TO STRONG 
WINDS SHOULD ACCOMPANY THE WAVE THROUGH TONIGHT AND PERHAPS INTO 
TOMORROW AS IT SHIFTS ANOTHER FIVE DEGREES WEST. HOWEVER...THE 
TREND IN THE MODELS IS TO WEAKEN THIS SYSTEM NEARLY COMPLETELY 
BY LATE WED. NEVERTHELESS...SCATTERED TO NUMEROUS TSTMS ARE NOW 
REACHING THE TROPICAL N ATLC WATERS E OF THE WAVE AXIS... 
STRETCHING FROM 10N TO 22N. 

SW N ATLC...
A WEAK SURFACE TROUGH ACCOMPANIES A COMPLEX AREA OF LOW PRESSURE 
IMMEDIATELY N OF THE AREA...WITH THE SURFACE TROUGH EXTENDING 
FROM 31N6W TO 25N70W. THIS FEATURE IS FORECAST TO DRIFT WESTWARD 
AND LOSE ITS IDENTITY BY EARLY THU. NW OF THE TROUGH...GENTLE NE 
WINDS PREVAIL WITH SEAS OF 1 TO 3 FT. SE OF THE TROUGH SE TO S 
WINDS OF 10 KT OR LESS ARE THE RULE EXCEPT SW WITHIN 120 NM OF 
THE TROUGH. SEAS RANGE FROM 2 TO 4 FT...HIGHEST E...AND 2 FT OR 
LESS W OF THE BAHAMAS.

OVER THE NEXT FEW DAYS...A WEAK COLD FRONT SHOULD PUSH INTO THE 
FAR NW WATERS EARLY THU AND BECOME DIFFUSE WHILE THE LOW-LEVEL 
SUBTROPICAL RIDGE AXIS EXTENDS FROM 27N65W TO THE CENTRAL 
BAHAMAS. EVEN THOUGH THE FIRST FRONT SHOULD RAPIDLY FADE AWAY... 
A NEW SURGE MOVING DOWN THE EAST COAST SHOULD INTRODUCE ANOTHER 
COLD FRONT OVER THE NW WATERS FRI...WITH THE FRONT STALLING FROM 
ABOUT 31N72W TO ABOUT CAPE CANAVERAL EARLY SAT AND THEN 
RETREATING AS A WARM FRONT LATE SAT INTO SUN. STRONG NE WINDS 
OVER A RELATIVELY NARROW FETCH AREA SHOULD GENERATE BUILDING 
SEAS OFFSHORE THE SE CONUS COAST LATE FRI AND SAT. ALTHOUGH MOST 
OF THE STRONG WINDS SHOULD REMAIN N OF THE AREA...ASSOCIATED 
SWELL SHOULD ARRIVE OVER THE NW WATERS...MOSTLY N OF 29N W OF 
75W...AND PRODUCE WAVE HEIGHTS OF 5 TO POSSIBLY 8 FT. ADDITIONAL 
NE SWELL BEING GENERATED OFF THE EAST COAST SHOULD ARRIVE OVER 
THE SW N ATLC WATERS LATER IN THE WEEKEND AND CAUSE SEAS TO 
BUILD TO 5 TO 7 FT NE OF THE BAHAMAS AND 3 TO 5 FT W OF THE 
BAHAMAS. 


WARNINGS...

ATLANTIC...
NONE.

CARIBBEAN...
NONE.

GULF OF MEXICO...
NONE.

FORECASTER KIMBERLAIN. TROPICAL PREDICTION CENTER.