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AGXX40 KNHC 210758 CCA
MIMATS

MARINE WEATHER DISCUSSION...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL
358 AM EDT SUN SEP 21 2014

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS.


...GULF OF MEXICO...

MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. MWW3/NWPS USED FOR WAVE PARAMETERS. HIGH CONFIDENCE THROUGH MON NIGHT THEN MEDIUM CONFIDENCE.

AN ASCAT SATELLITE PASS ALONG WITH BUOY OBSERVATIONS INDICATED THAT 10M WINDS OVER THE N CENTRAL GULF WERE STILL REACHING 20 KT...WITH SLIGHTLY STRONGER WINDS NOTED AT THE HIGHER PLATFORM OBSERVATIONS. BUOYS AND AN ALTIMETER SATELLITE PASS INDICATED SEAS OF 4 TO 5 FT...BUT THIS MAY NOT BE INDICATIVE OF THE AREA HIGHER WINDS OF HIGHER WINDS...AND THE FORECAST INTIALIZES WITH SEAS TO 6 FT IN THE WATERS OFFSHORE OF SE LOUISIANA. THE FRESH WINDS HAVE BEEN ACTIVE TO THE NORTH OF A FRONTAL BOUNDARY REACHING FROM CENTRAL FLORIDA TO THE CENTRAL GULF OVER THE PAST COUPLE OF DAYS. THE FRONT APPEARS TO BE LOSING SOME OF ITS CHARACTERISTICS AND MAY BE DRIFTING NORTHWARD SLIGHTLY AS A WEAK WARM FRONT. MODEL DIAGNOSTICS INDICATE IT IS LIKELY WASHING OUT TODAY AS THE AIRMASS MODIFIES OVER STILL WARM WATERS AND THE SUPPORTING UPPER DYNAMICS LIFT OUT TO THE NE. THIS WILL LEAVE DIMINISHING WINDS OVER THE N CENTRAL GULF IN THE SHORT TERM FORECAST...SIMILAR TO THE REMAINDER OF THE GULF WITH SEAS GENERALLY 1 TO 3 FT. A FEW SHOWERS AND THUNDERSTORMS ARE NOTED OVER THE FAR SE GULF. THIS ACTIVITY WILL SPORADICALLY CONTINUE WITH RICH DEEP LAYER MOISTURE IN PLACE ON THE SE EDGE OF A MOSTLY STATIONARY UPPER TROUGH EXTENDING FROM AN UPPER LOW OVER THE CAROLINAS TO THE CENTRAL GULF.

AN UPPER DISTURBANCE CURRENTLY OVER THE MID MISSISSIPPI WILL BE THE IMPETUS FOR THE NEXT ROUND OF WEATHER IN THE GULF...BRINGING A COLD FRONT INTO THE NORTHERN GULF MON. THE GFS AND UKMET HAVE DISPLAYED SOME CONSISTENCY WITH THIS FEATURE WITH THE UKMET REMAINING A BIT STRONGER. THE 00Z ECMWF HAS REVERSED COURSE AND IS SHOWING A SHARPER AND STRONGER UPPER TROUGH MORE IN LINE WITH THE UKMET. THE UKMET ALONG WITH THE CANADIAN SHOW WEAK CYCLOGENESIS OVER THE SOUTHEAST GULF BY LATE TUE WITH FRESH TO STRONG EASTERLIES OVER THE NE GULF. THE OFFICIAL FORECAST WILL FAVOR THE MORE CONSERVATIVE GFS WHICH ALSO CONTINUES TO SHOW FRESH TO STRONG EASTERLIES OVER THE NE GULF...MIMICKING THE ONGOING PATTERN THAT IS JUST ENDING IN THAT AREA. THE FRONT WILL SAG INTO THE SE GULF AND STALL INTO THU. OFFICIAL FORECAST IS SLIGHTLY ABOVE MWW3 OUTPUT IN THE NE GULF EARLY WED AT THE TIME OF PEAK WINDS TO 25 KT...WITH WAVE HEIGHTS REACHING 8 FT. SHOWERS AND THUNDERSTORMS ELSEWHERE LIGHT TO MODERATE EASTERLY WINDS WITH SLIGHT SEAS WILL PERSIST.


...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...

MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. MWW3/NWPS USED FOR WAVE PARAMETERS. HIGH CONFIDENCE.

A WEAK TROPICAL WAVE BETWEEN EASTERN CUBA AND PANAMA WILL MOVE INTO THE WESTERN CARIBBEAN THROUGH EARLY NEXT WEEK. ANOTHER WAVE PASSING 55W WILL ENTER THE EASTERN CARIBBEAN TONIGHT. AN ASCAT SATELLITE PASS FROM AROUND 02 UTC INDICATED FRESH TRADE WIND FLOW BETWEEN THE TWO TROPICAL WAVES OFF THE COAST OF VENEZUELA. THE COMBINATION OF RELATIVELY WEAK RIDGING N OF THE AREA AND APPROACH OF THE TROPICAL WAVE TO THE EAST WILL KEEP GENERALLY MODERATE TRADE WINDS ACROSS MOST OF THE CARIBBEAN FOR THE NEXT COUPLE OF DAYS...ALTHOUGH LOCALLY FRESH FLOW IS POSSIBLE OFF THE HIGH TERRAIN OFF THE NE COAST OF COLOMBIA DURING THE OVERNIGHT HOURS. NO SIGNIFICANT MODEL DIFFERENCES NOTED.


...SW N ATLANTIC INCLUDING THE BAHAMAS...

MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL. MWW3/NWPS USED FOR WAVE PARAMETERS. MEDIUM CONFIDENCE.

AN ASCAT SATELLITE PASS FROM AROUND 0145 UTC INDICATED A BROAD AREA OF 20 TO 25 KT WINDS N OF 28N W OF 70W...AHEAD OF A COLD FRONT REACHING FROM 1007 MB LOW PRES N OF THE AREA NEAR 33N76W 29N76W TO 28N80W. ALTHOUGH DEEPENING...THE LOW IS SHIFTING RAPIDLY NE ALONG THE EASTERN SEABOARD. BUOY 41032 NEAR 32N75W IS SHOWING SEAS TO 9 FT. HIGHER SEAS ARE POSSIBLE. THE AREA OF STRONG WINDS AND HIGH SEAS WILL DIMINISH FROM SOUTH TO NORTH THROUGH TODAY AS THE SUPPORTING LOW SHIFT NORTHWARD. THE SUBTROPICAL RIDGE WILL BUILD ALONG ROUGHLY 28N IN THE WAKE OF THE EXITING LOW PRES. GLOBAL MODELS ARE IN DECENT AGREEMENT SHOWING THE WESTERN EDGE OF THE MODEL ERODING AND SHIFTING EAST THROUGH MONDAY...AHEAD OF A COLD FRONT EXPECTED TO MOVE OFF THE NE FLORIDA COAST BY LATE MON. THE UKMET REMAINS STRONGER THAN THE OTHER MODELS SHOWING 20 TO 25 KT MON NIGHT INTO TUE OFF THE NE COAST OF FLORIDA...INFLUENCED BY AN AREA OF LOW PRES THE UKMET IS FORECASTING TO FORM IN THE EASTERN GULF. THE FORECAST REFLECTS THE MORE CONSERVATIVE GFS WHICH IS KEEPING THE STRONGER WINDS N OF THE AREA. THE FRONT SEEMS TO STALL OVER THE WATERS N OF THE BAHAMAS OFF NE AND E CENTRAL FLORIDA THROUGH THU.

$$


.WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:


.GULF OF MEXICO... NONE.


.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE.


.SW N ATLANTIC INCLUDING THE BAHAMAS... NONE.

$$

*FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF

NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP

FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE

$$


.FORECASTER CHRISTENSEN. NATIONAL HURRICANE CENTER.

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