000 AGXX40 KNHC 210727 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 230 AM EST THU JAN 21 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W SW N ATLC S OF 31N W OF 55W... A STATIONARY FRONT REMAINS STRETCHED OVER SE WATERS FROM 22N65W TO 20N70W. THE 0234 UTC ASCAT PASS SHOWS WINDS TO 25 KT E OF THE FRONT TO THE WINDWARD PASSAGE WHILE SHIP C6PT7 REPORTED 25 KT WINDS AT 0600 UTC JUST E OF THE FRONT. WINDS HERE ARE CURRENTLY THE STRONGEST OVER THE REGION. OTHERWISE...THE HIGH PRES BEHIND THE FRONT HAS BECOME THE DOMINATING WEATHER FEATURE OVER MUCH OF THE AREA WITH LIGHT ANTICYCLONIC FLOW AND SUBSIDING NE SWELL FOUND IN MUCH OF THE AREA WITH THE EXCEPTION OF THE STRAITS OF FLORIDA WHERE SE WINDS HAVE PICKED UP TO 20 KT IN THE RETURN FLOW BETWEEN THE HIGH PRES RIDGE ALONG 26N AND TROUGHING OVER THE WESTERN GULF. MODEL DIFFERENCES COME IN TO PLAY BY THU NIGHT OVER THE CAROLINA COAST...WITH THE GFS CRANKING UP A COASTAL LOW ALONG THE WARM FRONT AHEAD OF THE SYSTEM PASSING THROUGH MISSISSIPPI/OHIO VALLEYS FASTER THAN THE OTHER MODELS. WHILE ALL OF THE MODELS AGREE ON DEVELOPING THIS LOW AND MOVING IT OFFSHORE WELL NORTH OF THE AREA...PREFER TO SLOW DOWN THE GFS DEVELOPMENT OF THE SYSTEM BY 6 TO 12 HOURS TO BE MORE IN LINE WITH THE MODEL CONSENSUS. GALE FORCE WINDS ARE EXPECTED IN THE SOUTHERLY FLOW SE OF THE SYSTEM FRI NIGHT AND SAT MORNING BEFORE BEING PUSHED E OF THE AREA BY THE PROGRESSIVE COLD FRONT. HIGH PRES WILL QUICKLY PUSH THROUGH THE REGION BEHIND THIS FRONT SAT NIGHT AND SUN WITH THE GFS AND ECMWF AGREEING ON THE NEXT STRONG COLD FRONT REACHING NW WATERS MON MORNING WITH GALE FORCE WINDS EXPECTED AHEAD OF THE FRONT. CARIBBEAN AND TROPICAL N ATLC W OF 55W... THE ASCAT PASS FROM 0232 UTC SHOWS TRADES IN THE 25 TO 30 KT RANGE CONTINUING NEAR THE NE COAST OF COLOMBIA WHILE SHIP 9HUF9 REPORTED GALE FORCE WINDS NEAR 14N70W AT 0400 UTC. THE ASCAT SCATTEROMETER HAS A LOW BIAS FOR WINDS THIS STRONG. THE GALE WARNING WILL STAY UP FOR ANOTHER 24 HOURS ON THE NEXT HIGH SEAS PACKAGE. THE HIGH PRES TO THE NORTH SHIFTS SE INTO THE CENTRAL ATLC TONIGHT. LOOK FOR THE GALES TO COME DOWN AFTER THE NOCTURNAL MAXIMUM FRI MORNING. AS THE PEAK WINDS DIMINISH...LOOK FOR FRESH TO STRONG TRADE WINDS TO EXPAND ACROSS THE CENTRAL AND SW CARIBBEAN AS THE RIDGE SHIFTS E LATE TONIGHT THROUGH FRI NIGHT. MEANWHILE...SE FLOW IN THE NW CARIBBEAN HAS BUILT TO 25 TO 30 KT AHEAD OF THE NEXT SYSTEM IMPACTING THE GULF OF MEXICO. THE 0234 UTC ASCAT PASS CONFIRMS THESE WINDS AS DO SEVERAL SHIFT REPORTS IN FAR WESTERN WATERS AND THE YUCATAN CHANNEL. THESE WINDS WILL DIMINISH BELOW 20 KT BY FRI MORNING AS THE GULF SYSTEM SHIFTS INTO THE SW N ATLC...BUT THIS WILL JUST BE A BRIEF REPRIEVE WITH SE WINDS EXPECTED TO STRENGTHEN AGAIN LATE SAT AND SUN AHEAD OF A STRONG COLD FRONT MOVING INTO THE WESTERN GULF OF MEXICO. THE GFS AND ECMWF AGREE THAT THIS FRONT WILL PUSH THROUGH THE YUCATAN CHANNEL BY MON EVENING. GULF OF MEXICO... THE SOUTHERLY RETURN FLOW HAS PICKED UP TO 25 KT IN THE WESTERN GULF AND 25 TO 30 KT IN THE NORTHERN MIDDLE GULF AS A RESULT OF THE INCREASED PRES GRADIENT BETWEEN THE DEEP LAYER TROUGH OVER THE SOUTHERN PLAINS AND THE HIGH PRES TO THE E OVER THE SW N ATLC. WHILE THE MODELS ARE IN GOOD AGREEMENT WITH THE SURFACE LOW TRACK FROM THE PLAINS INTO THE MID MISSISSIPPI VALLEY TODAY...THE ECMWF IS DECIDEDLY WEAKER WITH THE WINDS IN THE GULF THAN THE GFS. THE GFS IS CLOSER TO THE CURRENT OBSERVATIONS...SO THE FORECAST RELIES MORE ON ITS SOLUTION. A PRE-FRONTAL TROUGH SE OF THE MAIN COLD FRONT...MAKES ITS WAY THROUGH THE WESTERN GULF TODAY AND THEN BECOMES STATIONARY AND DISSIPATES AS THE REMAINDER OF THE TROUGH CONTINUES E TROUGH NORTHERN FL BEFORE DISSIPATING IN THE EASTERN GULF ALONG 26N SAT. RETURN FLOW PICKS UP AGAIN IN THE WESTERN GULF SAT NIGHT IN RESPONSE TO THE NEXT SYSTEM EMERGING IN THE PLAINS. THIS STRONG COLD FRONT MOVES OFF THE TX COAST SAT AFTERNOON/EVENING AND THE GFS BRINGS WINDS TO 30 KT AHEAD OF THE FRONT SUN AS IT MOVES THROUGH THE NE GULF. THE GFS ENSEMBLES SHOW NO CHANCE OF GALES HERE AND THE OTHER OPERATIONAL MODELS ARE WEAKER...20 TO 25 KT. HIGH PRES BUILDS BEHIND THE FRONT MON. WARNINGS... ATLC... .GALE CONDITIONS EXPECTED N OF 27N E OF FRONT FRI NIGHT THROUGH SAT MORNING...AMZ080 CARIBBEAN... .GALE WARNING FROM 11N TO 15N BETWEEN 72W AND 77W...AMZ084 AND AMZ086. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER