000 AGXX40 KNHC 110651 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 255 AM EDT MON OCT 11 2010 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... 1018 MB HIGH PRES IS CENTERED OVER THE N CENTRAL GULF OF MEXICO WITH MAINLY LIGHT WINDS FOUND ACROSS THE GULF. THE PRES GRADIENT REMAINS RELATIVELY TIGHT OVER THE SE GULF BETWEEN THIS HIGH AND LOWER PRES TO THE S OVER THE WESTERN CARIBBEAN. NE WINDS TO 15 KT LIE OVER THE STRAITS OF FLORIDA. OVER THE NW GULF...WINDS HAVE ALSO INCREASED TO 15 KT AS THE PRES GRADIENT BUILDS BETWEEN THE HIGH AND AN APPROACHING COLD FRONT MOVING INTO THE U.S. SOUTHERN PLAINS. THIS HIGH PRES WILL MOVE INTO THE N CENTRAL GULF MON AND WEAKEN AS IT MEANDERS OVER THE N GULF AHEAD OF THE FRONT TUE AND WED. THE GFS ALLOWS WINDS OFF THE SOUTHERN TEXAS/NE MEXICAN COAST TO INCREASE TO 20 KT BRIEFLY THIS MORNING WHILE THE ECMWF IS NOT QUITE AS AGGRESSIVE...BUT ALSO VERY BRIEFLY GETS WINDS TO 20 KT. THE GEFS ENSEMBLES DO NOT SHOW MORE THAN A 5 PERCENT CHANCE OF 20 KT WINDS...SO WILL KEEP THE MENTION OF WINDS THAT STRONG OUT OF THE FORECAST. THE MODELS ARE GENERALLY IN GOOD AGREEMENT ON BRINGING THE COLD FRONT TO THE NW GULF COAST EARLY WED MORNING AND DISSIPATE IT OVER THE CENTRAL GULF BY WED NIGHT. THERE IS BETTER AGREEMENT ON WINDS REACHING 20 KT IN THE WESTERN GULF WED NIGHT INTO THU MORNING WHEN A SECONDARY SURGE OF COLD AIR MOVES IN BEHIND THIS FRONT WHICH WILL PASS THROUGH MUCH OF THE GULF BY FRI. BY THIS TIME...CONFIDENCE IN THE FORECAST DECREASES CONSIDERABLY BECAUSE IT BECOMES MORE DEPENDENT ON THE EVOLUTION OF THE LOW PRES SYSTEM IN THE NW CARIBBEAN. THIS LOW IS FORECAST TO GRADUALLY MOVE NORTH LATE WED AND MEANDER IN THE NW CARIBBEAN. DEEPENING OF THIS LOW IS POSSIBLE OVER THE NEXT FEW DAYS AND IT MAY BECOME A TROPICAL CYCLONE. SW N ATLC AND TROPICAL N ATLC... HIGH PRES WILL BUILD ALONG 31N SUN THROUGH TUE WITH MOSTLY LIGHT WINDS IN THE SW N ATLC N OF 27N AND ELY WINDS IN THE 10 TO 15 KT RANGE IN MUCH OF THE AREA S OF 25N EXCEPT OVER THE SE PORTION OF THE SW N ATLC AND THE NORTHERN HALF OF THE TROPICAL N ATLC S OF A SURFACE TROUGH LEFT OVER THE REGION IN THE WAKE OF OTTO. THE MODELS DIFFER WITH SPECIFICS OF THE STRENGTH AND NUMBER OF SURFACE WAVES THAT DEVELOP ALONG THIS TROUGH...BUT OVERALL KEEP THE TROUGH IN THE SAME GENERAL AREA IN THE SE PORTION OF THE SW N ATLC ZONE UNTIL IT SHIFTS E LATE TUE. SINCE CONFIDENCE IS LOW IN THE MODEL HANDLING OF ANY OF THESE WAVES...A BLEND OF SOLUTIONS WAS USED WHICH KEEPS WINDS LESS THAN 20 KT N OF THE TROUGH. MORE UNCERTAINTY COMES INTO THE FORECAST BY LATE WED WHEN THE MODELS GENERALLY AGREE ON SHEDDING SOME SHORTWAVE ENERGY NORTHEASTWARD FROM THE NW CARIBBEAN THROUGH CUBA AND THE BAHAMAS ON ITS WAY TOWARD BERMUDA BY FRI. A SURFACE TROUGH IS EXPECTED TO DEVELOP IN ASSOCIATION WITH THIS ENERGY...WITH NE WINDS EXPECTED TO BUILD ON THE W SIDE OF THE TROUGH AS IT STRETCHES NORTHEAST. THE MODELS DIFFER ON THE STRENGTH OF THE TROUGH AND WINDS AROUND IT. THE GFS DEVELOPS A SPOT LOW ON THE TROUGH...BUT IT IS ON THE MORE VIGOROUS SIDE OF THE MODEL CONSENSUS ALONG WITH THE CMC WHILE THE UKMET AND ECMWF ARE WEAKER AND MORE EASTERLY. THE MODELS DO AGREE THAT THIS ENERGY WILL BE PICKED UP BY THE AMPLIFYING DEEP LAYER TROUGH EXPECTED TO MOVE OFF THE SE COAST THU AND FRI. THE GFS IS ALSO ON THE FASTER SIDE OF THE CONSENSUS WITH THE SURFACE COLD FRONT ASSOCIATED WITH THIS DEEP LAYER TROUGH. THEREFORE...WILL ADJUST THE GFS TOWARD A SLOWER COLD FRONT MOVING OFF THE N FL COAST AND A WEAKER TROUGH STRETCHING INTO ITS LEADING EDGE AS IT MOVES THROUGH THE BAHAMAS THU/FRI. MEANWHILE...WINDS REMAIN UNDER 20 KT IN THE TROPICAL N ATLC THROUGH THE PERIOD. CARIBBEAN SEA... A BROAD AREA OF LOW PRESSURE LOCATED OVER THE SOUTHWESTERN CARIBBEAN IS FORECAST TO SLOWLY LIFT N-NW INTO THE NW CARIBBEAN THROUGH WED NIGHT AND THEN MEANDER AROUND THE NW CARIBBEAN THU AND FRI. SOME DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE OF DAYS AND IT MAY BECOME A TROPICAL CYCLONE. A SURFACE TROUGH EXTENDING N-NE OF THE LOW CENTER IS CURRENTLY FORECAST TO MOVE IN TANDEM WITH THE LOW PRES THROUGH TUE. NUMEROUS SHOWERS AND TSTMS ARE CURRENTLY NOTED WITHIN 180 NM NW QUADRANT OF THE LOW CENTER. WINDS AND SEAS WILL BE HIGHER NEAR TSTMS. STRONG NLY WINDS CONTINUE TO FUNNEL S INTO THE SW CARIBBEAN W OF THE TROUGH AXIS BETWEEN THE LOW AND THE COAST. WINDS AREA EXPECTED TO REMAIN STRONGEST ON THE NW SIDE OF THE LOW INTO WED WHERE THE PRES GRADIENT WILL BE STRONGEST BETWEEN THE LOW AND HIGH PRES OVER THE GULF OF MEXICO. THE FORECAST BECOMES ESPECIALLY UNCERTAIN BY THU. A TROPICAL WAVE CURRENTLY MOVING INTO THE CENTRAL CARIBBEAN IS FORECAST TO CONTINUE W THROUGH THE WESTERN CARIBBEAN THU S OF THE LOW. THERE COULD BE INTERACTION BETWEEN THE LOW AND THIS TROPICAL WAVE. IN ADDITION...THE STRENGTH OF THE DEEP LAYER TROUGH AMPLIFYING AS IT PASSES OFF THE SE U.S. COAST THU AND FRI COULD ALSO IMPACT THE SYSTEM. FOR NOW...THE MODEL CONSENSUS IS FOR THE LOW TO TAKE A SLIGHTLY E JOG AWAY FROM THE YUCATAN PENINSULA THU/FRI AS THE TROUGH PASSES TO ITS N. THIS SHOULD ALLOW THE LOW TO STAY AWAY FROM LAND LONG ENOUGH TO POTENTIALLY INTENSIFY. THE GFS HAS TRENDED TOWARD A STRONGER SOLUTION HERE WHILE THE ECMWF HAS MOVED AWAY FROM ITS EARLIER INLAND TRACK TOWARD A MORE MEANDERING TRACK IN THE NW CARIBBEAN THU/FRI. THE TROPICAL WAVE IS FORECAST TO PASS S OF THE LOW AND MAY HELP FEED SOME MOISTURE TO THE SYSTEM AS IT DOES. CURRENTLY...THE RIDGE OF HIGH PRES THAT HAS MOVED IN N OF THE CARIBBEAN IS ALLOWING FRESH TRADE WINDS TO BUILD OVER THE EASTERN TO THE E OF THE TROPICAL WAVE. THESE WINDS WILL MOVE THROUGH THE EASTERN AND CENTRAL CARIBBEAN MON THROUGH THU. WARNINGS... SW N ATLC... .NONE. CARIBBEAN... .NONE. TROPICAL N ATLC... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER