000 AGXX40 KNHC 100622 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 222 AM EDT THU SEP 10 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... EASTERLY WINDS HAVE INCREASED SLIGHTLY TO 10-15 KT ACROSS THE SOUTHERN WATERS ENHANCED BY TROUGHING OVER THE NW CARIBBEAN AND MEXICO. CONSEQUENTLY...SEAS HAVE BUILT TO 2-4 FT...HIGHEST OVER THE W PORTION WHERE THE FETCH IS MAXIMIZED. A WEAK PRESSURE PATTERN OVER THE SOUTHERN CONUS AND N GULF IS RESULTING IN LIGHT WINDS AND LOW SEAS...10 KT OR LESS WITH 1-2 FT SEAS...OVER THE NORTHERN WATERS. GFS AND ECMWF ARE NOW IN AGREEMENT IN SHOWING TROUGH DEVELOPMENT OVER THE W GULF FRI. BOTH MODELS SHOW THE TROUGH LIFTING NORTHWARD TOWARD THE N GULF COAST WITH LOW PRES DEVELOPING ALONG THE TROUGH FRI NIGHT. GFS DEVELOPS THIS LOW NEAR THE TEXAS COAST WHILE THE ECMWF'S LOW PLACEMENT IS ABOUT 180 NM TO THE EAST. WILL TAKE A MIDDLE GROUND IN TEXT AND GRAPHICS. BOTH SOLUTIONS SHOW A DEVELOPING WARM FRONT E OF THE LOW BY FRI NIGHT WITH THE LOW AND FRONT MOVING N OF THE AREA BY SAT NIGHT. I PLAN ON KEEPING FORECAST OF SE TO S 10-15 KT WINDS S OF THE FRONT AND E 10-15 KT N OF THE FRONT. HOWEVER...WINDS COULD BE STRONGER IF LOW PRES BECOMES BETTER DEFINED...AS SUGGESTED BY THE NAM. CARIBBEAN AND TROPICAL N ATLC... SURFACE OBSERVATIONS AND QUIKSCAT DATA INDICATE A SWATH OF 15-20 KT EASTERLY TRADES FROM 12N-17N BETWEEN 69W-76W WITH COMBINED SEAS ESTIMATED TO BE 6-9 FT. A WEAK TROUGH FROM 24N62W TO THE VIRGIN ISLANDS...FORMERLY A CLOSED LOW...IS PRODUCING NE TO E 15-20 KT WINDS WITHIN 60 NM OF THE AXIS. OTHERWISE...THE FLOW IS GENERALLY 10-15 KT ACROSS THE REGION. GLOBAL MODELS SHOW SURFACE HIGH PRESSURE MEANDERING AND POSSIBLY STRENGTHENING SLIGHTLY OVER THE CENTRAL ATLC THROUGH FRI NIGHT. THIS PATTERN WILL MAINTAIN MODERATE TO FRESH TRADES. BY THE WEEKEND...THE HIGH IS EXPECTED TO WEAKEN AND DRIFT SOUTHEAST IN RESPONSE TO A COLD FRONT MOVING ACROSS THE W ATLC. THIS WILL ALLOW WINDS TO DECREASE ACROSS THE EASTERN CARIBBEAN AND TROPICAL N ATLC. HOWEVER...SE WINDS MAY INCREASE OVER THE NW CARIBBEAN DUE TO THE TROUGH OF LOW PRESSURE 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 BEGINNING LATE THIS WEEKEND. SW N ATLC... A TROUGH REMAINS QUASI-STATIONARY OVER THE NW WATERS ...CURRENTLY FROM A 1008 MB LOW CENTERED A FEW HUNDRED NM OFF THE MID-ATLC COAST TO THE NW BAHAMAS. THE PRESSURE GRADIENT BETWEEN THE TROUGH AND A RIDGE OVER THE EAST COAST OF THE U.S. IS SUPPORTING NE 15 KT WINDS W OF THE TROUGH...AS REVEALED BY A 0148 UTC QUIKSCAT PASS. THE TROUGH IS EXPECTED TO SLOWLY SHIFT NE OVER THE NEXT COUPLE OF DAYS. BY FRI...MODELS ARE SHOWING A WARM FRONT DEVELOP OVER THE NW WATERS. THIS FRONT BECOMES RE-ENERGIZED BY SUN AND THEN MOVES SE AS A COLD FRONT REACHING FROM NEAR BERMUDA TO THE NW BAHAMAS MON. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE $$ FORECASTER CANGIALOSI