000 AGXX40 KNHC 191858 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 250 PM EDT TUE APR 19 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. SW N ATLC W OF 55W... STRONG HIGH PRES COVERS THE MUCH OF THE ARE...EXCEPT FOR THE SE PORTION...WHERE LOWER PRESSURES ASSOCIATED WITH A COUPLE OF TROUGHS IS RESULTING IN WIDESPREAD CLOUDINESS WITH SCATTERED SHOWERS AND TSTMS FROM 23N TO 28N E OF 66W. 12 UTC MODEL RUNS WITH THE EXCEPTION OF THE ECMWF WHICH IS FROM 00 UTC LAST NIGHT ARE STILL HINTING THAT LOW PRES WILL DEVELOP JUST E OF THE AREA ALONG A SURFACE TROUGH THAT IS CURRENTLY JUST E OF PUERTO RICO S OF ABOUT 26N. THE DIFFERENCES STILL TO BE CONSIDERED FOR THIS AND FUTURE FORECASTS ARE WITH TRACK OF LOW ONCE IT CROSSES THE EASTERN PORTION ON THU THROUGH FRI. MODEL CONSENSUS IS FOR LOW TO TRACK W TO WNW THEN EVENTUALLY SW DAYS 4 AND 5 FT AS IT GETS NUDGED SW BY ATLC HIGH PRES BUILDING SW. THE DETERMINISTIC GFS AND ITS ENSEMBLE GUIDANCE STILL THE OUTLIER WITH TAKING THE LOW MORE TOWARDS THE NW BEFORE BEING MOSTLY ABSORBED BY A FRONTAL BOUNDARY SAT...WITH ITS REMNANT TROUGH FEATURE THAN PUSHED SW TOWARDS THE SE BAHAMAS ON SUN. FOR THIS FORECAST WILL CONTINUE WITH SIMILAR THINKING OF PREVIOUS FORECAST WITH TROUGH PRES GRADIENT BETWEEN LOW AND THE HIGH PRES ALLOWING FOR NE-E 20-30 KT WINDS FROM 20N TO 27N BETWEEN 50W AND 63W AS SUGGEST BY ASCAT DATA FROM THIS MORNING. WILL FORECAST THE DEVELOPING LOW NEAR 25N62W 1012 MB IN 24 HOURS...NEAR 26N63W IN 48 HOURS AS 1011 MB THEN TO NEAR 26N68W IN 72 HOURS AND WEAKENING INTO A TROUGH AS IT MOVES WSW THEREAFTER. WILL KEEP MENTION OF POSSIBLE GALE CONDITIONS OVER THE FAR EASTERN WATERS OF THE SW N ATLC FOR THU AND FRI...ALTHOUGH IT IS POSSIBLE GALE FORCE CONDITIONS MAY OCCUR SOONER THERE WITH ONLY A SLIGHT INTENSIFICATION OF THE GRADIENT EVEN BEFORE THE LOW FORMS. EXPECT SEAS OF 13 OR 14 FT NEAR THE LOW CENTER THU AND FRI. SEAS SHOULD THEN SUBSIDE LATER FRI THROUGH SAT TO ABOUT 8-10 FT OVER THE EASTERN PORTION OF THE AREA N OF ABOUT 24N. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... RELATIVELY LIGHT WINDS WILL PERSIST OVER THE MUCH OF CARIBBEAN AND TROPICAL N ATLC THROUGH SUN WITH THE SUBTROPICAL HIGH AND TRADE WINDS DISTURBED BY THE PERSISTENT DEEP LAYER TROUGHING OVER THE WESTERN PORTION OF THE SW N ATLC AREA. RETURN FLOW HAS INCREASED OVER THE FAR NW CARIBBEAN AS THE PRES GRADIENT STRENGTHENED BETWEEN HIGH PRES ACROSS THE SW N ATLC AND EASTERN GULF OF MEXICO AND INCREASED TROUGHING OVER THE SOUTHERN PLAINS AND NE MEXICO. LATEST OBSERVATIONS FROM THE FAR WESTERN CARIBBEAN CONTOUR TO SHOW SE WINDS OF 20-25 KT S OF 19N AND W OF 83W WITH SEAS THERE MAXING OUT TO 7 FT. WILL KEEP THESE WINDS A LITTLE LONGER (THROUGH AT LEAST WED NIGHT) IN THIS UPCOMING FORECAST AS I FEEL GRADIENT WILL BE SLOW IN RELAXING GIVEN THE CURRENT SYNOPTIC SET-UP. THE FAR SOUTHERN PORTION OF AN ASCAT PASS FROM THIS MORNING SHOWED A SE WINDS OF 20-25 KT JUST BRUSHING THE FAR NE PORTION OF THE TROPICAL N ATLC DUE TO STRONG GRADIENT OVER THE CENTRAL ATLC. THESE WINDS ARE EXPECTED TO SLOWLY DIMINISH THROUGH WED MORNING AS A SURFACE TROUGH OVER THE N CENTRAL WATERS PULLS OFF TO THE W. MAIN ISSUE WILL BE LONG PERIOD N SWELLS OF 7 TO 8 FT EXPECTED TO PROPAGATE INTO THE FAR NORTHERN WATERS THROUGH PERHAPS EARLY THU AFTERNOON BEFORE SUBSIDING TO 5 FT. GULF OF MEXICO... HIGH PRES CONTINUES TO DOMINATE THE GULF AS LOW PRES DEEPENS OVER THE LOWER MIDWEST REGION OF THE U.S. ALLOWING FOR THE EXISTING PRES GRADIENT TO MAINTAIN FRESH TO STRONG SE WINDS ACROSS MOST OF THE MIDDLE AND WESTERN PORTIONS OF THE GULF AS BEING SEEN IN THE BUOY ARRAY THROUGHOUT THOSE SECTIONS. LATEST SEA STATE ANALYSIS FROM THIS MORNING REVEALED HIGHEST SEAS OF 7 FT OVER THE FAR WESTERN WATERS FROM 22N TO 27N W OF 94W AS BEING REPORTED BY BUOYS 42020 AT 27N96W AND SW GULF BUOY 42055 AT 22N94W. SEAS ELSEWHERE ARE IN THE 3-5 FT RANGE...EXCEPT LOWER RANGES OF 2-3 FT E OF 88W. WITH THE PRESENT SYNOPTIC PATTERN HOLDING FIRM THROUGH THE NEXT FEW DAYS...THIS WILL KEEP STATUS QUO WITH THE CURRENT CONDITIONS WITH VERY LITTLE...IF ANY...CHANGES EXPECTED THROUGH SUN AS FRONTS STAY WELL TO THE NW OF THE GULF. WARNINGS.. ATLC... .AMZ080...GALE CONDITIONS EXPECTED THU AND FRI FROM 24N TO 28N BETWEEN 65W AND 69W... CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE