000 AGXX40 KNHC 050701 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EST WED JAN 05 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. GULF OF MEXICO... THE 00Z GFS AND ECMWF ARE DIFFERENT FROM DAY 1 WITH THE FORECAST IN THE GULF OF MEXICO WITH THE GFS DEVELOPING 20 KT SW WINDS S OF THE SURFACE LOW TRACKING JUST INLAND OF THE NE GULF COAST THIS AFTERNOON WHILE THE ECMWF WAITS UNTIL AFTER SUNSET. THE ECMWF IS ALSO SLOWER THAN THE GFS TO CARRY THE SURFACE LOW EASTWARD INTO THE ATLC. WILL NOT CHANGE CONTINUITY WHICH SIDES WITH THE FASTER GFS SOLUTION. THE MODELS THEN COME INTO REASONABLE AGREEMENT WITH THE FORECAST THROUGH FRI BUT THEN DIVERGE WITH THE NEXT SYSTEM EXPECTED TO MOVE TO THE TX COAST SAT NIGHT. THE ECMWF IS FASTER TO INCREASE THE SOUTHERLY RETURN FLOW AHEAD OF THE SYSTEM OVER THE WESTERN GULF AND IS STRONGER WITH THAT RETURN FLOW ON SAT THAN THE GFS. THE GFS GOES ON TO CARRY A WEAKER SURFACE LOW THROUGH THE CENTRAL GULF SUN ON A CONSIDERABLY MORE SOUTHERLY TRACK THAN THE 00Z ECMWF... UKMET...AND CMC. THE ECMWF TRACK IS CLOSEST TO THE MODEL CONSENSUS...BUT CONFIDENCE IS LOW IN ITS FORECAST FOR GALE FORCE WINDS NEAR THE LOW ON SUN BECAUSE OF THE LARGE RUN-TO-RUN VARIABILITY WITH THE STRENGTH AND TIMING OF THIS SOUTHERN STREAM SYSTEM. WILL LEAN ON THE ECMWF FORECAST...BUT WILL HOLD OFF ON THE MENTION OF GALES UNTIL THE MODELS SHOW BETTER CONTINUITY WITH THIS SYSTEM. SW N ATLC... A WEAK FRONTAL BOUNDARY LIES FROM 31N75W TO CAPE CANAVERAL THIS MORNING. THIS FRONT WILL STALL LATE TODAY AND BEGIN TO LIFT N BY TONIGHT AS A WAVE DEVELOPS ALONG THE FRONT IN THE GULF OF MEXICO THAT MOVES QUICKLY THROUGH NW WATERS. THE GFS IS SOMEWHAT FASTER THAN THE ECMWF CARRYING THE LOW NE INTO THE ATLC. A BLEND OF THEIR SOLUTIONS WILL BE USED FOR THE FORECAST THROUGH THU. THE GFS APPEARS TO HAVE CONVECTIVE FEEDBACK ISSUES OVER NE WATERS THU NIGHT WHEN IT PRODUCES A BULLS-EYE OF APPROX 1.5 INCHES OF PRECIPITATION ALONG THE FRONTAL BOUNDARY THAT IS ASSOCIATED WITH A BRIEFLY INTENSE SHORTWAVE. THE GFS DEVELOPS GALE FORCE WINDS ALONG THE FRONT IN ASSOCIATION WITH THIS SYSTEM WHILE THE ECMWF KEEPS WINDS JUST BELOW GALE UNTIL FRI. A SECONDARY SURGE OF COLD AIR WILL MOVE IN BEHIND THE MAIN COLD FRONT SAT...AND BOTH THE GFS AND ECMWF AGREE ON BUILDING WINDS TO GALE FORCE OVER NE WATERS SOMETIME ON SAT AHEAD OF THE SURGE...WITH THE GFS A BIT EARLIER THAN THE ECMWF. THESE TIMING DIFFERENCES ARE HARD TO RESOLVE THIS FAR OUT IN THE FORECAST...SO A BLEND OF THE GFS AND ECMWF WILL BE USED. CARIBBEAN AND TROPICAL N ATLC... HIGH PRES N OF AREA CONTINUES TO PRODUCE FRESH TO STRONG WINDS ACROSS MUCH OF THE CENTRAL AND EASTERN CARIBBEAN SEA. WINDS WILL GRADUALLY DIMINISH OVER THE ENTIRE AREA THROUGH THU MORNING. THE COLD FRONT MOVING THROUGH THE GULF OF MEXICO THU WILL REACH THE NW CARIBBEAN ON FRI AND GRADUALLY MOVE THROUGH THE GREATER ANTILLES WHILE WEAKENING THROUGH SUN. MEANWHILE...CENTRAL ATLC HIGH PRES WILL BUILD THU THROUGH THE WEEKEND ALLOWING FRESH TRADE WINDS TO RETURN TO THE SOUTHERN HALF OF THE TROPICAL N ATLC ZONE BY FRI. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER