000 AGXX40 KNHC 151940 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 340 PM EDT FRI JUN 15 2012 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... A 1015 MB LOW IS ANALYZED IN THE FAR NE PORTION AT 29.5N86W DRIFTING W. THE LOW IS ALONG A SURFACE TROUGH THAT EXTENDS FROM THE FL BIG BEND AREA TO THE LOW AND TO JUST SE OF LOUISIANA. ELSEWHERE HIGH PRES IS RIDGING SWD FROM THE ERN U.S. SWD INTO THE ERN GULF. LATEST BUOY OBSERVATIONS FROM THE NE GULF SHOW NE-E WINDS OF 20 KT TO THE E OF THE LOW WHERE THE TIGHT PRES GRADIENT IS LOCATED. ELSEWHERE BUOYS AND OIL PLATFORMS ARE REPORTING GENERALLY E-SE WINDS OF 10 KT...EXCEPT IN THE SRN PORTION OF THE ERN GULF WHERE N-NE WINDS OF 10 KT ARE NOTED. OBSERVED SEAS ARE IN THE RANGE OF 2-3 FT...EXCEPT 4-5 FT IN THE FAR WRN GULF JUST OFFSHORE THE TEXAS COAST. MODELS INDICATE THAT THE RIDGE WILL CONTINUE TO SURGE SWD INTO THE ERN GULF INTO EARLY NEXT WEEK ALLOWING FOR THE NE-E 20 KT WINDS TO CONTINUE IN THE NE GULF THROUGH LATE SUN. WITH THE RIDGE BUILDING SWD...THIS WILL TEND TO STEER THE LOW IN A W TO SW MOTION THROUGH THE NEXT 18-24 HRS THEN IN A MORE WWD DIRECTION. THE 12 UTC RUN OF THE GFS ALONG WITH ITS PREVIOUS SOLNS REVEAL THE CYCLONIC CIRCULATION RELATED TO THE LOW AS IT TRACKS TOWARDS THE NW GULF OVER THE NEXT 48 HRS. SINCE THIS CIRCULATION PRESENTLY IS REVEALED ON VISIBLE IMAGERY AND ON SOME OF THE NWS WEATHER RADARS OF THE NE GULF COAST...I WILL USE THE GFS GUIDANCE FOR THE LOW FORECAST ACROSS THE NRN GULF. THE LOW APPEARS THAT IT WILL REMAIN ABOUT 1014 TO 1015 MB THROUGH THE NEXT 48 HRS...AND MAY VERY WELL OPEN INTO A TROUGH BEFORE IT REACHES NE TEXAS ON MON. THE LOW'S IMPACTS TO WINDS AND SEAS WILL BE SEEN AS WHAT IS CURRENTLY OBSERVED WITH ITS INTERACTION WITH THE RIDGE ALLOWING FOR A TIGHT PRES GRADIENT IN THE NE GULF PRODUCING NE-E WINDS OF 20 KT THERE. THESE WINDS SHOULD DIMINISH LATE SUN. SCATTERED TSTMS WITHIN 150-180 NM E OF THE LOW MAY PRODUCE GUSTY WINDS AT TIMES. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A TRPCL WAVE IS OVER THE SE CARIBBEAN SEA EARLY THIS AFTERNOON MOVING W AT 15-20 KT. BOTH BUOY AND ASCAT DATA FROM THIS MORNING AND EARLY AFTERNOON REVEALED MODERATE TO FRESH BREEZES ACROSS MUCH OF THE CARIBBEAN E OF THE TROPICAL WAVE...AND MOSTLY LIGHT E-SE TRADES W OF THE WAVE. A WEAK 1009 MB LOW HAS FORMED AGAIN ON THE MONSOON TROUGH SEGMENT IN THE FAR SW CARIBBEAN NEAR 11N81W. EXTENSIVE DEEP ATMOSPHERIC MOISTURE HAS RETURNED TO THE WRN CARIBBEAN ASSOCIATED WITH THE LARGE MONSOON IN THE ERN PACIFIC THAT JUTS EWD ACROSS CENTRAL AMERICA AND MOST OF THE YUCATAN PENINSULA. THE DETERMINISTIC MODELS TEND TO LIFT THE MONSOON TROUGH SEGMENT TO THE N OVER THE NEXT FEW DAYS ALONG WITH THE 1009 MB LOW AS THE GFS AND ECMWF ENSEMBLES ARE ON PAR WITH DEPICTING THIS SCENARIO. SIMILARLY TO YESTERDAY'S FORECAST THINKING...BASED ON MODEL CONSENSUS AND GFS ENSEMBLE WILL KEEP THE LOW JUST OFFSHORE OF THE NE COAST OF HONDURAS BY MON AND TOWARDS THE GENERAL AREA JUST TO THE NE OF THE GULF OF HONDURAS TUE AND WED. THE HPC/NHC AFTERNOON CONFERENCE CALL AGREED ON SUCH A SCENARIO. RIGHT NOW IT DOES NOT APPEAR THE LOW WILL HAVE LARGE IMPACTS ON WINDS AND SEAS...BUT WILL HAVE TO CLOSELY MONITOR FUTURE MODEL TRENDS FOR ANY FORESEEABLE MAJOR CHANGES RELATED TO THE LOW IN THE EVENT IT WERE TO BECOME MORE ORGANIZED. THE WAVE IN THE FAR SE CARIBBEAN WILL SHRINK IN AMPLITUDE AS IT REACHES 70W/71W BY SUN...AND EVENTUALLY BECOME DIFFUSE. THE WAVE WILL BE FOLLOWED BY FRESH TRADES OVER THE EASTERN CARIBBEAN AND TROPICAL N ATLC THROUGH WED. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... THE PRELIMINARY 18 UTC SURFACE MAP HAS A WEAK 1011 MB LOW AT 30N68W WITH A WEAKENING COLD FRONT EXTENDING FROM IT SW TO 27N73W ...THEN BECOMING A FRONTAL TROUGH TO THE NRN BAHAMAS. LATEST BUOY AND ASCAT DATA SHOW RELATIVELY LIGHT S TO SW WINDS ACROSS THE AREA SE OF THE FRONT...EXCEPT FOR AN AREA OF SW 20 KT WINDS N OF 26N BETWEEN 60W AND 64W WHERE A TIGHTER PRES GRADIENT IS PRESENT. NE WINDS OF 10-15 KT ARE NW OF THE FRONT...EXCEPT FOR 15-20 KT N OF 29N. SEAS ARE IN THE RANGE OF 2-4 FT EXCEPT 4-5 FT IN A NE SWELL OVER THE FAR N CENTRAL PORTION AND 7-9 FT N OF 29N BETWEEN 75W AND 79W. THE LOW IS FORECAST TO MOVE TO JUST NE OF THE AREA NEAR 32N64W BY SAT MORNING WITH A TROUGH SW TO 26N71W TO THE CENTRAL BAHAMAS PER THE DETERMINISTIC GFS AND ECMWF AND THE GFS ENSEMBLE GUIDANCE...THEN TRACK NE TO NEAR BERMUDA BY SAT NIGHT AND SUN. A TROUGH TRAILING FROM THE LOW WILL EXTEND SW FROM NEAR 31N68W TO THE SOUTHERN BAHAMAS LATE SUN INTO MON...FROM 31N67W TO THE CENTRAL BAHAMAS BY LATE TUE AND FROM 27N70W TO NEAR 23N79W BY WED. IN THE SHORT TO MEDIUM RANGES OF THE FORECAST STRONG HIGH PRES FROM THE U.S. E COAST BUILDING SWD NW OF THE COLD FRONT WILL CAUSE THE PRES GRADIENT TO TIGHTEN OVER THE NW WATERS EXPECTED TO LEAD TO NE WINDS OF 20 KT OVER THE FAR NW AND NRN PORTIONS TONIGHT AND INTO EARLY SUN BEFORE THE GRADIENT WEAKENS. EXPECT SEAS TO BUILD TO 9 FT IN A NE SWELL IN THE FAR NW WATERS THROUGH SAT BEFORE SUBSIDING INTO EARLY NEXT WEEK. THE TIGHT GRADIENT SE OF THE TROUGH TO 26N OF SW 20 KT WINDS WILL REMAIN THROUGH EARLY TUE SUN AND INTO TUE...THEN DIMINISH TO 10-15 KT LATER TUE AND WED. NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE (LOWER CASE) GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE