000 AGXX40 KNHC 250750 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 349 AM EDT THU SEP 25 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. LATEST MWW3 USED FOR WAVE PARAMETERS. HIGH CONFIDENCE. LATEST SURFACE ANALYSIS DEPICTS A PERSISTENT WEAKENING STATIONARY FRONT EXTENDING FROM E CENTRAL FLORIDA TO JUST N OF TAMPA BAY AND SW TO NEAR 26N87W. WEAK HIGH PRES IS PRESENT ELSEWHERE...EXCEPT FOR OVER THE N CENTRAL GULF WHERE HIGH PRES THERE IS STRONGER. LATEST BUOY REPORTS AND ASCAT DATA SHOW MODERATE NE TO E WINDS N OF THE FRONTAL BOUNDARY...AND MOSTLY GENTLE NE TO E WINDS S OF THE FRONT...WITH THE EXCEPTION OF THE EASTERN PART OF THE SW GULF WHERE GENTLE WINDS ARE E TO SE IN DIRECTION. THE OBSERVATIONS SHOW SEAS IN THE RANGES OF 4-5 FT OVER MOST ZONES...WITH THE EXCEPTION OF THE SE PORTION WHERE SEAS ARE LOWER...IN THE 2-4 FT RANGE AND IN THE N CENTRAL SECTION WHERE SEAS ARE HIGHEST IN THE 4-6 FT RANGE. SATELLITE WATER VAPOR SHOWS AMPLE DEEP LAYER MOISTURE CONFINED TO OVER THE EASTERN PORTION OF THE GULF TO THE SE OF AN UPPER TROUGH THAT STRETCHES FROM THE EASTERN U.S. SW TO 25N88W TO THE WESTERN YUCATAN PENINSULA. THE COMBINATION OF THIS TROUGH AND THE PRESENT STATIONARY FRONTAL BOUNDARY CONTINUE TO ENHANCE ATMOSPHERIC INSTABILITY PRIMARILY TO THE SE OF THE STATIONARY FRONT WHERE SCATTERED TO NUMEROUS SHOWERS AND TSTMS ARE OBSERVED. A SHORTWAVE TROUGH OVER THE WESTERN GULF IN COMBINATION WITH LOW-LEVEL CONVERGENCE PRESENT ALONG THE FRONT IS RESULTING IN SHOWERS AND TSTMS ALONG AND N OF THE STATIONARY FRONT FROM 26N TO 29N BETWEEN 89W AND 93W. ISOLATED SHOWERS AND TSTMS ARE OVER THE REMAINDER OF THE GULF. MOISTURE FROM THE CARIBBEAN SEA WILL CONTINUE TO ADVECT NWD ACROSS THE SE AND ERN PART OF THE GULF UNDER THE SW FLOW ALOFT E OF THE UPPER TROUGH CONTRIBUTING TO THE SHOWER AND TSTM ACTIVITY NOTED THERE. THE CURRENT PATTERN IN PLACE SHOULD ALLOW FOR THIS MOISTURE TO CONTINUE THROUGH FRI. GLOBAL MODELS SUGGEST...FOR THE MOST PART...THAT WEAK LOW PRES DEVELOPS ALONG A TROUGH THAT WAS THE WESTERN SEGMENT OF THE STATIONARY FRONTAL BOUNDARY OVER THE W CENTRAL GULF ON SAT AS ANOTHER SHARP UPPER TROUGH MOVES OFF THE TEXAS COAST ACROSS THE WESTERN GULF PROVIDING ADDITIONAL LIFT ALONG THE STATIONARY FRONT. THE DETERMINISTIC MODELS PORTRAY THIS LOW AS A RATHER WEAK FEATURE LIFTING IT NE TOWARDS THE GENERAL AREA OF THE N CENTRAL GULF SAT AND SAT NIGHT ...WITH AN INLAND PSN NEAR SE LOUISIANA BY EARLY ON SUN. WIND AND WAVEHEIGHT VALUES IN THE NDFD GRIDS WILL BE ADJUSTED ACCORDINGLY IF REQUIRED. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. FOR WAVE HEIGHTS USED NWPS WAVE PARAMETERS. HIGH CONFIDENCE. RELATIVELY QUIET CONDITIONS CONTINUE OVER THE CARIBBEAN AND TROPICAL N ATLC WATERS PER LATEST SHIP AND BUOY DATA ALONG WITH PARTIAL ASCAT DATA FROM LAST NIGHT AS THE SUBTROPICAL RIDGE N OF THE BASIN REMAINS RATHER WEAK. BASED ON LATEST MODEL DATA THESE CONDITIONS ARE EXPECTED TO CHANGE VERY LITTLE THROUGH MOST OF THE PERIOD...WITH THE EXCEPTION OF THE LATTER PERIODS IN THE S CENTRAL PORTION OF THE SEA. ELY WINDS WILL REMAIN IN THE GENTLE TO MODERATE CATEGORY...AND SEAS AT RATHER LOW LEVELS THROUGH THE PERIOD...EXCEPT IN THE S CENTRAL PORTION BEGINNING LATE SUN AT WHICH TIME E-SE TRADES ARE EXPECTED TO INCREASE TO 20 KT UNDER A TIGHTENING PRES GRADIENT BEHIND A TROPICAL WAVE DESCRIBED BELOW. THIS SHOULD ALLOW SEAS THERE TO BUILD TO THE 5-7 FT RANGE BEGINNING SUN AND INTO MON. THE 06 UTC SURFACE ANALYSIS HAS A TROPICAL WAVE OVER THE W CENTRAL CARIBBEAN EXTENDING FROM CUBA NEAR 21N79W TO NEAR 10N79W...MOVING W AT 10 KT. ANOTHER WAVE IS OVER THE WESTERN TROPICAL N ATLC WATERS APPROACHING THE LESSER ANTILLES NEAR 59W...AND MOVING W AT ABOUT 10-15 KT. AMPLE DEEP LAYER MOISTURE PRODUCING CLUSTERS OF SCATTERED SHOWERS AND TSTMS REMAINS ENTRENCHED ACROSS THE AREA WITH INSTABILITY RELATED TO THE TROPICAL WAVES HELPING TO FURTHER ENHANCE THE ACTIVITY. THE TROPICAL WAVE OVER THE W CENTRAL CARIBBEAN WILL MOVE ACROSS THE THE WESTERN CARIBBEAN THROUGH FRI NIGHT. THE TROPICAL WAVE OVER THE WESTERN TROPICAL N ATLC WILL CROSS THE LESSER ANTILLES TONIGHT THROUGH AND FRI...THE CENTRAL CARIBBEAN FRI NIGHT AND SAT...AND THE WESTERN CARIBBEAN SEA SAT NIGHT THROUGH SUN NIGHT. GUSTY WINDS ARE POSSIBLE WITH SHOWER AND TSTM ACTIVITY... ESPECIALLY THAT ASSOCIATED WITH THE WAVES. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL. MWW3/NWPS BLEND WITH OFFICIAL USED FOR WAVE PARAMETERS. HIGH CONFIDENCE. THE 06 UTC SURFACE ANALYSIS HAS A PERSISTENT STATIONARY FRONT OVER THE FAR NW CORNER OF THE BASIN EXTENDING FROM 31N79W TO INLAND FLORIDA AT CAPE CANAVERAL. AN INVERTED TROUGH ALONG 78W N OF CUBA WAS NICELY DEPICTED IN THE 0156 UTC ASCAT PASS FROM LAST NIGHT...AS WELL AS IN THE WINDS AND PRES DERIVED FROM BUOY OBSERVATIONS AND OBSERVATIONS FROM THE BAHAMAS. A RELATIVELY WEAK RIDGE EXTENDS FROM NEAR BERMUDA SW TO NEAR THE CENTRAL BAHAMAS. THE ASCAT DATA ALONG WITH BUOY OBSERVATIONS...AND A FEW SHIP REPORTS ARE PRESENTLY SHOWING GENTLE E-SE WINDS ACROSS THE AREA. THE OBSERVATIONS ALONG WITH RECENT ALTIMETER PASSES SHOW SEAS IN THE 4-6 FT RANGE E OF THE BAHAMAS...AND 1-3 FT SEAS W OF THE BAHAMAS. THE STATIONARY FRONT JUST NW OF THE BASIN WILL GRADUALLY BECOME DIFFUSE THROUGH SAT. NE TO E WINDS BEHIND THE FRONT HAVE DIMINISHED OVER THE PAST 24 HRS...AND SEAS THERE HAVE LOWERED. THE TROUGH ALONG 78W WILL MOVE WESTWARD TO ACROSS FLORIDA TONIGHT INTO FRI. ABUNDANT DEEP LAYER TROPICAL MOISTURE ASSOCIATED WITH THE TROUGH WILL RESULT IN ADDITIONAL SCATTERED TO NUMEROUS SHOWERS AND TSTMS TO AFFECT MUCH OF THE WESTERN PORTION THROUGH FRI. GUSTY WINDS AND LIGHTNING STRIKES CAN BE EXPECTED WITH THIS ACTIVITY. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 AGUIRRE. NATIONAL HURRICANE CENTER.