000 AGXX40 KNHC 090554 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 155 AM EDT WED SEP 09 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE PRESSURE PATTERN REMAINS WEAK ACROSS THE GULF OF MEXICO... ALLOWING ELY WINDS TO BE 10 KT OR LESS ACROSS THE REGION. ACCORDINGLY...SEAS ARE 2 FT OR LESS...THOUGH SEAS COULD BE A FT HIGHER OVER THE FAR W WATERS WHERE THE FETCH IS MAXIMIZED. MANY OF THE MODELS SHOW A SURFACE TROUGH OR LOW DEVELOPING OVER THE NW WATERS THU OR FRI THEN MOVING NORTHEASTWARD AND INLAND OVER LOUISIANA THIS WEEKEND. GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT OVERALL...WHICH PROVIDES MORE CONFIDENCE THAN WE HAD YESTERDAY. I PLAN ON KEEPING AN OPEN TROUGH ACROSS THE NW ZONE IN NEXT PACKAGE WITH WINDS OF 15 KT. HOWEVER...WINDS COULD BE STRONGER IF A CLOSED LOW DEVELOPS. CARIBBEAN AND TROPICAL N ATLC... SURFACE OBSERVATIONS AND QUIKSCAT DATA INDICATE A SWATH OF 20-25 KT EASTERLY TRADES FROM 11N-16N BETWEEN 69W-77W WITH COMBINED SEAS ESTIMATED TO BE 7-10 FT. SATELLITE IMAGES SHOW A SMALL LOW MOVING NW NEAR 20N60W. QUIKSCAT DATA REVEAL 20 KT E WINDS WITHIN 90 NM N OF LOW. OTHERWISE...THE FLOW IS GENERALLY 10-15 KT ACROSS THE REGION. GLOBAL MODELS SHOW SURFACE HIGH PRESSURE MEANDERING OVER THE CENTRAL ATLC THROUGH FRI. THIS WILL MAINTAIN MODERATE TO FRESH TRADES. BY THE WEEKEND...THE HIGH IS EXPECTED TO WEAKEN AND DRIFT SOUTH ALLOWING WINDS TO DECREASE ACROSS THE EASTERN CARIBBEAN AND TROPICAL N ATLC. HOWEVER...SE WINDS MAY INCREASE OVER THE NW CARIBBEAN DUE TO THE LOW PRESSURE TROUGH OVER THE GULF OF MEXICO. ONLY IMPACT FROM HURRICANE FRED WILL BE LONG PERIOD E SWELL ELEVATING SEAS TO 6-8 FT OVER THE NE PART OF THE TROPICAL N ATLC ZONE LATE THIS WEEKEND. SW N ATLC... A TROUGH REMAINS QUASI-STATIONARY OVER THE NW WATERS ...CURRENTLY FROM A 1006 MB LOW OFF THE MID-ATLC COAST TO THE NW BAHAMAS. A WELL-DEFINED WIND SHIFT REMAINS EVIDENT BUT MAGNITUDES ON BOTH SIDES ARE AROUND 10 KT S OF 31N. THIS FEATURE IS EXPECTED TO SLOWLY SHIFT E AND WEAKEN THROUGH THU. THE FORECAST OVER THE NEXT FEW DAYS APPEARS STRAIGHTFORWARD. SURFACE RIDGING IS EXPECTED TO REMAIN EAST OF THE AREA AND TROUGHING EXPECTED TO REMAIN OVER THE NW CORNER OF THE ZONE. THIS WILL ALLOW FOR NEARLY UNIFORM SE-S 10-15 KT FLOW N OF 25N...EXCEPT NE W OF THE TROUGH...AND SIMILAR MAGNITUDE E-SE WINDS S OF 25N. BY SUN...GLOBAL MODELS ARE SUGGESTING TROUGH AMPLIFICATION OFF THE EAST COAST OF THE U.S. WHICH COULD DRAG A COLD FRONT ACROSS THE N WATERS. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE $$ FORECASTER CANGIALOSI