000
AGXX40 KNHC 190718
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
315 AM EDT SAT SEP 19 2009

GULF OF MEXICO...
FAIRLY DEEP LAYERED CYCLONE WHICH HAS PERSISTED ACROSS THE GULF 
STATES AND NORTHERN GULF OF MEXICO FOR NEARLY A WEEK APPEARS TO 
BE FILLING AND SHOULD BEGIN TO LIFT OUT TO THE N TODAY WITH ANY 
INFLUENCE ON THE GULF MARINE WEATHER WANING BY LATE SUN. A WEAK 
RIDGE BUILDS WWD ACROSS THE GULF MON AND TUE. THIS RIDGE IS 
REPLACED BY ANOTHER RIDGE BUILDING SE OUT OF THE SRN PLAINS. 
THIS ALLOWS LIGHT E TO SE RETURN FLOW TO GRADUALLY BACK INTO THE 
E AND NE LATE TUE AND CONTINUING INTO WED. ELSEWHERE A BROAD 
TROUGH WILL DEVELOP OVER THE S CENTRAL GULF SUN AND CONTINUE 
INTO MON. 

SW N ATLC...
A DISSIPATING QUASI-STATIONARY TROUGH EXTENDS FROM 31N73W TO NW 
BAHAMAS WITH BROAD TROUGHING TO THE STRAITS OF FLORIDA. THIS 
TROUGH WILL DISSIPATE IN PLACE OR OVER PORTIONS OF FLORIDA LATER 
TODAY. LIGHT WINDS OF 10 TO LOCALLY 15 KT ARE NOTED ON BOTH 
SIDES OF THE TROUGH. THE REMNANTS OF TC FRED...A TIGHT SWIRL OF 
LOW CLOUDS IN SHORTWAVE IR SATELLITE IMAGERY...WAS NEAR 26N70W 
TONIGHT MOVING WNW 10-12 KT. THE EDGE OF A 0200 UTC ASCAT PASS 
STILL SHOWED 20-25 KT WINDS WITHIN 90-120 NM OF THE LOW IN THE 
NE SEMICIRCLE WITH SEAS ESTIMATED NEAR 8 FT. THE SURFACE 
TROUGH THAT THIS LOW IS EMBEDDED WITHIN IS MOVING IN TANDEM AND 
IS EXPECTED TO MOVE WNW TO ALONG 74W LATE TODAY AND OPEN UP INTO 
A TROUGH. THIS TROUGH CONTINUES MOVING NW AND SHOULD REACH THE E 
COAST OF FLORIDA LATE MON...THEN HANG UP ALONG THE FLORIDA COAST 
ON TUE AND WED. HIGH PRES WILL BUILD ACROSS THE AREA FROM THE E 
BEHIND THIS TROUGH WITH E-SE WINDS 15 KT AND ISOLATED AREAS OF 
20 KT WINDS MON INTO TUE...WHICH SUBSIDE ON WED. 

CARIBBEAN AND TROPICAL N ATLC...
THE GRADIENT BETWEEN HIGH PRESSURE OVER THE SUBTROPICAL ATLANTIC 
AND A TROPICAL LOW NEAR 13N42W HAS PRODUCED A BROAD AREA OF 
20-25 KT WINDS PER A 2116 UTC HIGH RESOLUTION QSCAT AND 
SUBSEQUENT 0018 UTC ASCAT PASS. SEAS WERE IN THE 7-10 FT RANGE 
IN A MIX OF SE AND NE SWELLS IN THIS FETCH. THIS AREA WILL SHIFT 
SLOWLY W AND WEAKEN BEHIND THE REMNANTS OF FRED...BUT WITH THE 
NELY SWELL MOVING INTO THE ATLC WATERS AND PASSAGES OF THE 
CARIBBEAN. AS FOR THE TROPICAL LOW...THERE IS A MODERATE CHANCE 
THAT THIS SYSTEM COULD DEVELOP INTO A TROPICAL CYCLONE DURING 
THE NEXT 48 HOURS. IN ANY EVENT...THE PRESSURE GRADIENT BETWEEN 
THE LOW AND HIGH PRESSURE TO THE N WILL MAINTAIN A BROAD ZONE OF 
20-25 KT WINDS WITHIN SEVERAL DEGREES TO THE N...AND LIKELY 
25-30 KT WITHIN 120 NM OF SO OF THE N SEMICIRCLE...AT LEAST 
THROUGH THE NEXT 48 HOURS. ACROSS THE CARIBBEAN...THE REMNANTS 
OF FRED AND RESULTANT WEAK RIDGING N OF THE AREA HAVE 
INTERRUPTED THE NORMAL TRADE WIND PATTERN ACROSS THE ENTIRE 
CARIBBEAN LEAVING 10-15 KT FLOW ACROSS THE BASIN...WITH THE 
EXCEPTION OF 20 KT WINDS NEAR THE COAST OF COLOMBIA PER A 0158 
UTC ASCAT PASS. AS HIGH PRESSURE BUILDS BEHIND THE REMNANTS OF 
FRED...FRESH TRADES WILL RETURN TO THE SRN CARIBBEAN SUN 
THROUGH WED WITH WINDS NEAR 20 KT AND SEAS GRADUALLY BUILDING TO 
NEAR 8 FT...WHILE THE REST OF THE BASIN IS AROUND 15 KT AND SEAS 
5 FT OR LESS. 

ATLC...
.NONE.

CARIBBEAN...
.NONE.

GULF OF MEXICO...
.NONE

$$
FORECASTER COBB