000 AGXX40 KNHC 311944 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 PM EST MON JAN 31 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. ATLC...HIGH PRES CENTERED JUST NE OF THE AREA WILL SHIFT E AND DISSIPATE THROUGH TUE AFTERNOON AS A COLD FRONT MOVES INTO THE NW WATERS BY EARLY WED NIGHT. THE FRONT WILL REACH FROM 31N73W TO NEAR VERO BEACH BY THU MORNING...THEN BEGIN TO WEAKEN AS ITS EXTENDS FROM NEAR 30N65W TO S FLORIDA LATE THU INTO FRI MORNING. THE WESTERN PORTION OF THE FRONT IS FORECAST TO LIFT N AS A WARM FRONT ON FRI AS LOW PRES DEVELOPS IN THE GULF OF MEXICO AND TRACKS NE. THE ASSOCIATE COLD FRONT WILL APPROACH THE FAR NW PORTION SAT. THE MODELS ARE IN DECENT AGREEMENT ON MOVING A COLD FRONT OFF THE NE FL COAST LATE WED...BUT LARGER DIFFERENCES ARISE WITH THE EVOLUTION OF THE SYSTEM OVER THE GULF OF MEXICO THAT IMPACT THE SURFACE FRONT OVER THE SW N ATLC. THE 00Z GFS HAS NOW BECOME A SIGNIFICANTLY FAST OUTLIER ALOFT WITH THE UPPER LOW EXPECTED BY THE MODEL CONSENSUS TO BE OVER THE SOUTHERN PLAINS ON FRI AND LIFTS THE FRONTAL BOUNDARY N OUT OF NW WATERS FASTER THAN THE OTHER MODELS. HPC HAS DISCOUNTED THE 00Z GFS SOLN AND FAVORS SOMETHING CLOSER TO THE MODEL CONSENSUS LIKE THE 00Z UKMET AND ECMWF. CARIBBEAN AND TROPICAL N ATLC... WEAK HIGH PRES NE OF THE REGION WILL MAINTAIN A RATHER LIGHT PRES GRADIENT OVER MUCH OF THE AREA THROUGH WED. THE GRADIENT TIGHTENS LATE WED THROUGH SAT ALLOWING FOR TRADES TO INCREASE OVER THE CENTRAL AND EASTERN PORTIONS OF THE SEA...AND OVER MUCH OF THE TROPICAL N ATLC WITH SEAS BUILDING TO 9 FT IN LONG FETCH NE TO E SWELLS. NE WINDS OF 25 TO 30 KT ALONG COAST OF CLOMBAI WHERE MAX SEAS ARE UP TO 12 FT BEGIN TO SUBSIDE LATE FRI THROUGH SAT. GULF OF MEXICO... LATEST BUOY OBSERVATIONS ALONG WITH PARTIAL ASCAT DATA SHOW RELATIVELY LIGHT E TO SE WINDS THROUGHOUT THE GULF WITH SEAS ON THE RATHER LOW SIDE...2-4 FT WITH THE HIGHEST NEAR 26N93W. THESE VALUES ARE IN VERY CLOSE AGREEMENT WITH THE LATEST WAVEWATCH MODEL GUIDANCE. THE 18 UTC PRELIMINARY SURFACE ANALYSIS REVEALS A WEAK RIDGE JUST N OF THE AREA TO THE E OF 93W. WEATHER CONDITIONS WILL BE FAST IN CHANGING OVER THE GULF AS THE BROAD MID TO UPPER LEVEL RIDGE SHIFTS EASTWARD AHEAD OF A DEEPENING SHORTWAVE TROUGH CURRENTLY OVER THE SW U.S. A JET STREAM ALONG THE SOUTHERN PERIPHERY OF THE TROUGH IS ADVECTING UPPER LEVEL MOISTURE IN THE FORM OF BROKEN HIGH CLOUDINESS NEWD FROM THE EASTERN PACIFIC TO ACROSS NORTHERN MEXICO AND TO THE FAR WESTERN SECTION OF THE GULF WHILE AT THE SAME A VERY COLD ARCTIC AIR MASS IS DROPPING SSE ACROSS THE GREAT PLAINS. AHEAD OF THIS COLD AIR MASS...THE SURFACE COLD AND STATIONARY FRONTS OVER WESTERN AND CENTRAL TEXAS IS POISED TO MOVE OFFSHORE THE TEXAS AND SW LOUISIANA COASTS DURING THU MORNING. THE 12 UTC NWP MODEL RUN IS VERY SIMILAR TO THE PREVIOUS 06 UTC RUN WITH RESPECT TO FRONTAL TIMING INTO THE NW GULF TUE MORNING...AND WITH TRACKING THE ATTENDANT SURFACE LOW NE ACROSS THE UPPER OHIO VALLEY THROUGH LATE THU WITH THE GFS MODEL A TID FASTER IN THE DETERMINISTIC RUN LATE THU THROUGH SAT IN MOVING THE FRONT THROUGH THE MIDDLE AND EASTERN GULF ZONES. FOR THIS FORECAST PACKAGE WILL LEAN TOWARDS CONSENSUS FOR FRONTAL POSITION FOR DAYS 4 AND 5 FT WITH THE SLOWER FRONTAL PROGRESS ACROSS THE EASTERN GULF. IN ANY EVENT...A VERY COLD AIR MASS WILL SPREAD ACROSS THE GULF IN THE WAKE OF THE FRONT USHERING IN NW TO N WINDS OF 20-30 KT WITH THE STRONGEST OF THE RANGE IN THE FAR WESTERN PORTION. POSSIBLE HIGHER GUSTS TO NEAR GALE FORCE MAY HAPPEN OVER THE FAR WESTERN WATERS ALONG THE COAST...AND NEAR THE MEXICO COAST TUE MORNING INTO EARLY AFTERNOON. WILL ANALYZE LATEST MODEL RUNS AND UPPER AIR DATA TO DETERMINE IF GALE WARNINGS NEED TO BE POSTED FOR A PORTION OF THE WESTERN GULF LATER THIS EVENING FOR THE TUE PERIOD. WAVEWATCH BUILDS SEAS UP TO 11 FT IN THE SW ZONE WED. THIS LOOKS REASONABLE FOR NOW. THE FRONT SHOULD REACH FROM SE LOUISIANA TO WESTERN BAY OF CAMPECHE TUE NIGHT...FROM THE FLORIDA BIG BEND TO EASTERN BAY OF CAMPECHE WED MORNING...THEN WEAKEN AND BECOME STATIONARY FROM NEAR NEAR FORT MYERS FLORIDA TO THE EASTERN BAY OF CAMPECHE THU MORNING. MODELS ALSO IN PRETTY GOOD AGREEMENT IN DEVELOPING ON THE FRONT OVER THE S CENTRAL GULF LATE THU...AND TRACKING NE ALLOWING FOR THE FRONT TO LIFT BACK N AS A WARM FRONT ON FRI WITH THE TRAILING COLD FRONT SWEEPING ACROSS THE MIDDLE AND EASTERN PORTIONS FRI INTO EARLY SAT...AND REACH FROM TAMPA TO NE YUCATAN PENINSULA BY LATE SAT. WINDS INCREASE TO 30 KT NW OF THE FRONT IN THE SW GULF FRI WITH SEAS TO POSSIBLY AS HIGH AS 14 FT. BY SAT...WINDS BECOMING NW TO N THROUGHOUT BEHIND THIS SECOND FRONT WITH SPEEDS OF 20-25 KT IN THE MIDDLE GULF AND 15-20 KT ELSEWHERE EXCEPT DIMINISHING TO 10-15 KT IN THE NW GULF AS HIGH PRES SETTLES IN OVER THAT PORTION. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE