000 AGXX40 KNHC 190752 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 250 AM EST MON NOV 19 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... LATEST AND RECENT BUOY AND OIL RIG PLATFORM OBSERVATIONS SHOW NE-E 15 KT THROUGHOUT...EXCEPT IN THE E GULF PORTION OF 25N WHERE NE 15-20 KT ARE NOTED. LIGHTER WINDS ARE OVER THE FAR NW WATERS WHERE E-SE WINDS WITH SPEEDS OF 5-10 KT ARE OCCURRING. THE PRELIMINARY 6 UTC SYNOPTIC SCALE ANALYSIS HAS A HIGH PRES RIDGE THAT STRETCHES FROM VERY STRONG HIGH PRES OVER NEW ENGLAND SW TO THE WESTERN AND N CENTRAL GULF. A WEAK SURFACE TROUGH MOVING W 15-20 KT EXTENDS FROM 27N89W SE TO JUST NE OF THE YUCATAN PENINSULA. THE INTERACTION BETWEEN THE RIDGE AND THE TROUGH IS RESULTING IN THE NE WINDS OF 15-20 KT OVER THE SRN PART OF THE E GULF. THE BUOY OBSERVATIONS ARE REPORTING SEA HEIGHTS OF 3-4 FT... EXCEPT FOR A SMALL POCKET OF HIGHER SEAS OF 4-6 FT WITH THE NE 15-20 KT WINDS...AND LOWER SEAS OF 2 FT N OF 28N. SATELLITE IMAGERY SHOWS SCATTERED TO BROKEN LOW LEVEL CLOUDS ASSOCIATED WITH THE AFOREMENTIONED TROUGH MOVING W WITH POSSIBLE ISOLATED SHOWERS OVER THE MIDDLE AND EASTERN GULF ZONES S OF 28N AND BETWEEN 83W-92W. THE WATER VAPOR SATELLITE IMAGERY DEPICTS BROAD UPPER TROUGHING THAT EXTENDS FROM ALONG THE MID-ATLC STATES SOUTHWESTWARD ACROSS THE FLORIDA PENINSULA AND TO THE FAR SE GULF. HIGH AMPLITUDE RIDGING FOLLOWS IN BEHIND THE TROUGH OVER THE WESTERN GULF PORTION. CONFLUENT FLOW ALOFT BETWEEN THE TROUGH AND RIDGING IS DRAWING DRY AIR ESE ACROSS THE EASTERN GULF...AND OVER MUCH OF THE MIDDLE GULF WATERS. UPPER LEVEL MOISTURE IN THE FORM OF SCATTERED THIN CLOUDS IS STREAMING NE FROM THE EASTERN PACIFIC ...AND THEN EASTWARD ACROSS THE RIDGE CREST IN NE TEXAS WHERE IT THEN SPILLS SEWD ACROSS THE NW GULF. SHALLOW LOW LEVEL MOISTURE IN THE FORM BROKEN LOW CLOUDS WITH ISOLATED SHOWERS IS CONFINED TO THE FAR SW GULF. THE BROAD UPPER LEVEL TROUGH WILL MOVE E OF THE AREA LATER THIS MORNING ALLOWING FOR THE UPPER RIDGE TO OVER THE WESTERN GULF TO SHIFT EASTWARD THROUGH WED. WITH REGARDS TO HOW THIS WILL REFLECT ON THE FORECAST WINDS AND SEAS EXPECT ONLY A FEW MINOR CHANGES TO CURRENT WIND/SEA CONDITIONS. THE NE 15-20 KT WINDS IN SRN PART OF THE E GULF WILL DIMINISH TO 10-15 KT THIS AFTERNOON WITH SEAS LOWERING TO 3-5 FT AND REMAIN AT THAT RANGE THROUGH MUCH OF WED. CONDITIONS ELSEWHERE ARE EXPECTED TO REMAIN VERY NEAR THE SAME AS PRESENTLY THROUGH DAY 5. THE ONLY FORESEEABLE CHANGE APPEARS THAT WILL HAPPEN IN THE SRN HALF OF THE E GULF DURING WED AND LASTING INTO FRI AS THE WESTERN GULF RIDGE BEGINS TO WEAKEN THIS AFTERNOON...AND THROUGH TUE. STRONGER CONTINENTAL SURFACE HIGH PRES THEN BUILDS SEWD OVER MUCH OF THE GULF WED THROUGH FRI WITH THE PRES GRADIENT BETWEEN IT AND LOWER PRES E OF FLORIDA ALLOWING FOR NE 20 KT WINDS TO MATERIALIZE OVER THE WATERS OF THE SRN PORTION OF THE E GULF. SEAS THERE SHOULD BUILD TO AROUND 6 FT. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE HIGH RESOLUTION ASCAT SWATH FROM 0258 UTC LAST NIGHT REVEALED N-NE WINDS OF 10-15 KT OVER WRN CARIBBEAN FROM CUBA SWD TO PANAMA AND NW COLOMBIA. ANOTHER ASCAT PASS FROM 0120 UTC SHOWED LIGHT E WINDS OVER THE EASTERN PART OF THE SEA...AND NE 15-20 KT WINDS OVER JUST ABOUT THE ENTIRE TROPICAL N ATLC ZONES...WITH E-SE WINDS OF 5-10 KT IN THE FAR SRN PART OF THAT ZONE. SEA STATE...SEAS RANGE FROM 3-4 FT ACROSS MOST OF THE CARIBBEAN EXCEPT FOR 2-3 FT N OF ABOUT 16N BETWEEN PUERTO RICO AND WESTERN CUBA...AND A SMALL POCKET OF 6-7 FT IN THE FAR SW CARIBBEAN WHERE A SMALL POCKET OF 20-25 KT N WINDS LINGER FROM ABOUT 11N TO 14N W OF 82W...HOWEVER THESE WINDS ARE EXPECTED TO DIMINISH TO 15-20 KT TONIGHT. THE CURRENT SYNOPTIC PATTERN IS FORECAST BY MODELS TO REMAIN IN PLACE THROUGH LATE TUE NIGHT. THEREAFTER...STRONGER HIGH PRES SURGES S FROM THE GULF OF MEXICO TO OVER THE WESTERN CARIBBEAN WED AND THU BRINGING INCREASING N WINDS OF 20 KT MUCH OF THE NW CARIBBEAN WATERS WITH SEAS BUILDING TO AROUND 7 FT. THE N WINDS OF 15-20 KT OVER A PORTION OF THE SW CARIBBEAN ARE FURTHER REINFORCED BY THE NLY HIGH PRES SURGE AND LAST THROUGH THE END OF THE FORECAST PERIOD. THE 15-20 KT E WINDS OVER TROPICAL N ATLC ARE FORECAST BY THE MODELS TO BEGIN TO DIMINISH TO 10-15 KT TONIGHT AND HOLD THROUGH DAY 5 WHILE VEERING TO THE SE-S IN RESPONSE TO THE ATLC COLD FRONTAL FRONTAL BOUNDARIES ADVANCING EASTWARD. LONG PERIOD NE SWELLS THERE RESULTING IN COMBINED SEAS OF UP TO 8 FT ARE FORECAST BY THE GRIDDED WWWIII GUIDANCE TO SUBSIDE TO 6 FT TONIGHT...TO 3 TO 5 FT TUE AND 3 TO 4 FT BY THU. SATELLITE IMAGERY HAS BEEN HIGHLIGHTING...AND IS CURRENTLY SHOWING AMPLE DEEP ATMOSPHERIC MOISTURE CONFINED TO THE SW AND CENTRAL PORTION OF THE CARIBBEAN AND ALSO ACROSS THE CENTRAL CARIBBEAN SEA. THIS MOISTURE IS IN THE FORM OF MULTILAYERED CLOUDS WITH SCATTERED SHOWERS AND TSTMS ASSOCIATED WITH UPPER LEVEL DIFFLUENCE SE THE UPPER TROUGH IN THE FAR SE GULF OF MEXICO THAT EXTENDS SWWD TO GULF OF HONDURAS. EXPECT THIS ACTIVITY TO CONTINUE THROUGH WED BEFORE TAPERING OFF. SW N ATLC W OF 55W... THE PRELIMINARY 0600 UTC SURFACE ANALYSIS HAS A WEAK 1016 MB LOW AT 31N78W WITH A TRAILING COLD FRONT SSW TO THE NW BAHAMAS...AND TO JUST SE OF THE S FLORIDA. TO ITS E...A PERSISTENT LARGE TROUGH EXTENDS FROM JUST E OF THE FORECAST WATERS AT 31N64W SW TO OVER THE FAR SE WATERS AND TO NEAR NE HISPANIOLA. SATELLITE IMAGERY SHOWS ABUNDANT DEEP ATMOSPHERIC MOISTURE WITH SCATTERED SHOWERS AND TSTMS CONTINUING OVER THE SE PORTION OF THE FORECAST ZONES ASSOCIATED WITH THE TROUGH...FURTHER AIDED BY AN UPPER LEVEL TROUGH THAT EXTENDS FROM A VORT MAX ASSOCIATED WITH THE LOW AT 3178W SSW TO WESTERN CUBA. SCATTERED TSTMS MOVING NE ARE ALSO OVER THE FAR NE ZONE. THE 0120 UTC HIGH RESOLUTION ASCAT PASS NOTED GENERALLY LIGHT ELY NE-E WINDS OVER THE EASTERN PORTION OF THE BASIN ACROSS THE TROUGH...WHILE A 0302 UTC ASCAT PASS SHOWED NW-N WINDS OF 20-30 KT SW OF THE LOW...WITH THE HIGHEST OF THE WINDS N OF 30N. BUOYS IN THAT VICINITY ARE REPORTING COMBINED SEAS OF 10 TO 11 FT. OBSERVED SEAS ELSEWHERE ARE IN THE 5-7 FT RANGE IN A NE SWELL TO THE NE OF THE BAHAMAS WITH SEAS OF 6-9 FT N OF 27N E OF 78W. THE PRES DIFFERENCE BETWEEN THE LOW AND STRONG HIGH PRES RIDGING TO ITS N AND NW WILL MAINTAIN WILL SLOWLY EASE THROUGH WED AS THE LOW LIFTS NE AND THE RIDGE WEAKENS. THE STRONG WINDS BETWEEN IT AND THE COAST SHOULD THEN LOWER TO NW AROUND 15-20 KT BY WED AS THE COLD FRONT ASSOCIATED WITH THE LOW SWEEPS EASTWARD...AND MERGES WITH THE PERSISTENT SURFACE TROUGH DESCRIBED ABOVE. GLOBAL MODELS CONSISTENTLY KEY IN ON A SECONDARY NLY SURGE (REINFORCING DRY COLD FRONT) THAT QUICKLY PUSHES SE ACROSS THE WESTERN AND CENTRAL PORTIONS OF THE BASIN WED AND THU FOLLOWED BY ANOTHER AREA OF HIGH PRES. THE ASSOCIATED PRES GRADIENT WILL INCREASE NW-N WINDS TO 20-25 KT OVER THOSE WATERS WITH SEAS BUILDING TO 9-14 FT. THIS NEXT COLD FRONT WILL THEN MOVE ACROSS THE REMAINDER OF THE BASIN FRI. COMPLEX LOW PRES JUST N OF THE AREA FROM WHICH THE FRONT WILL EXTEND SHOULD COMBINE INTO ONE LOW BY DAY 5 AND WHILE DEEPENING. MODELS DIFFER ON EXACT PRES AND FORECAST PSNS OF THE LOW. THE MAIN THING TO NOTED WILL BE THAT A VERY TIGHT PRES GRADIENT SETS UP OVER THE NE WATERS WITH POSSIBLE W-NW WINDS OF 20-30 KT BORDERING TO NEAR GALE FORCE AS SUGGEST BY THE MODELS. SEAS ARE FORECAST BY THE GRIDDED NOAA III WAVEWATCH GUIDANCE TO BUILD TO HIGH LEVELS (POSSIBLY TO 17 OR 18 FT) OVER THE N CENTRAL WATERS THU AND SPREAD SSE INTO FRI TOWARDS THE NE PORTION. WILL MAKE UPDATES TO LONG TERM PORTION OF THE FORECAST AS NEEDED BASED ON FUTURE MODEL TRENDS. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE