000 AGXX40 KNHC 291828 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 228 PM EDT MON OCT 29 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... SCATTERED SHOWERS AND ISOLATED TSTMS ARE ACTIVE IN THE BAY OF CAMPECHE ALONG A REMNANT BOUNDARY OF AN OLD COLD FRONT... SUPPORTED IN PART BY CONVERGENT NORTHERLY FLOW AND MID TO UPPER LEVEL MOISTURE ORIGINATING FROM THE NE PACIFIC. FRESH TO STRONG WINDS NEAR THE COAST OF VERACRUZ ARE FORECAST TO DIMINISH BY TONIGHT. OTHERWISE...FRESH TO STRONG WINDS IN THE E GULF ARE A RESULT OF BUILDING COLD HIGH PRES OVER THE CENTRAL MISSISSIPPI VALLEY SPILLING OUT ACROSS THE GULF...AND LARGE AND EXPANSIVE HURRICANE SANDY WELL NE OF THE REGION. MEANWHILE MODERATE TO LOCALLY FRESH WINDS ARE IN THE REMAINDER OF THE GULF AWAY FROM THE OUTER INFLUENCE OF SANDY. THE STRONGER WINDS WILL GRADUALLY DIMINISH TO 20 KT OR LESS BY WED MORNING BASIN WIDE AS THE HIGH SHIFTS SOUTHWARD SETTLING OVER THE CENTRAL GULF WED. A WEAK COLD FRONT OR TROUGH WILL ROTATE THROUGH THE N CENTRAL AND NE GULF THU WITH LITTLE IMPACT TO SENSIBLE WEATHER OTHER THAN A WIND SHIFT. NEW HIGH PRES WILL QUICKLY BUILD IN BEHIND THE FRONT OR TROUGH LATE THU THROUGH SAT. BY THU THROUGH SAT...LIGHT TO MODERATE WINDS AND PRIMARILY 2-3 FT WILL PREVAIL ACROSS THE GULF. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A TROUGH...THE REMNANTS OF A COLD FRONT...REACHES FROM EASTERN CUBA NEAR 20N78W TO WESTERN HONDURAS NEAR 16N88W. SATELLITE WIND DATA AND SURFACE OBSERVATIONS INDICATE FRESH TO LOCALLY STRONG WINDS NEAR THE YUCATAN CHANNEL BEHIND THE FRONT. A DISORGANIZED AREA OF SHOWERS AND ISOLATED TSTMS ARE PRESENT WITHIN 120 NM E OF THE TROUGH AS INDICATED BY SATELLITE IMAGERY AND LIGHTNING DATA. THE TROUGH IS FORECAST TO DISSIPATE LATE TUE. OTHERWISE LIGHT TO MODERATE WINDS EXIST IN THE CENTRAL AND E CARIBBEAN ON EITHER SIDE OF A SURFACE TROUGH WHICH EXTENDS FROM 17N69W TO 12N70W. SCATTERED SHOWERS AND TSTMS ARE PRESENT WITHIN 120 NM E OF THE TROUGH BEING ADVECTED TO THE NE BY SW FLOW IN THE MID AND UPPER LEVELS. THIS TROUGH IS FORECAST TO DRIFT WESTWARD DURING THE NEXT FEW DAYS...REACHING 80W BY FRI MORNING WHEN WEAK LOW PRES MAY DEVELOP ALONG IT NEAR 10N/11N PRIOR TO THE TROUGH REACHING CENTRAL AMERICA. WINDS WILL INCREASE TO 20 KT IN THE WAKE OF THE TROUGH N OF THE COAST OF COLOMBIA FRI. LARGE LONG PERIOD NW SWELL SPREADING OUTWARD FROM HURRICANE SANDY WILL CONTINUE TO AFFECT THE ATLC/CARIBBEAN PASSAGES AND THE TROPICAL N ATLC WATERS THROUGH WED...SUBSIDING THU AND FRI. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... THE CENTER OF HURRICANE SANDY IS WELL N OF THE BASIN...BUT ITS VERY LARGE CIRCULATION WILL CONTINUE TO PRODUCE FRESH TO NEAR GALE FORCE WINDS AS WELL AS A HUGE AREA OF LARGE SEAS OVER A WIDE SWATH OF THE SW N ATLC. A SURFACE TROUGH W OF SANDY REACHING INTO THE AREA NEAR 31N75W TO EASTERN CUBA WILL REMAIN NEARLY STATIONARY WHILE STRONG WINDS CONTINUE TO OCCUR W OF IT AS COLD AIR CONTINUALLY FUNNELS OVER THE GULF STREAM. A GALE WARNING MAY BE NEEDED N OF 29N W OF THE FRONT BEGINNING TONIGHT THROUGH TUE IF CURRENT MODEL TRENDS CONTINUE. WFO JACKSONVILLE ALREADY HAS A GALE WARNING IN PLACE FOR THEIR OUTER COASTAL WATERS IN ANTICIPATION OF THESE WINDS. LARGE LONG PERIOD NE SWELL IMPACTING NE CARIBBEAN ISLANDS ARE EXPECTED TO DIMINISH TUE THROUGH WED. MARINE CONDITIONS ARE EXPECTED TO IMPROVE SIGNIFICANTLY BY THU AND FRI. A BLEND OF THE UKMET...GFS...AND ECMWF WAS USED FOR THE GRIDDED WINDS THROUGH 48 HOURS...FOLLOWED BY A GFS AND ECMWF BLEND THEREAFTER. WAVEWATCH GUIDANCE WAS USED PRIMARILY FOR WAVE HEIGHTS WITH SLIGHT MODIFICATIONS TO THE FIRST 12 HOURS BASED ON THE LATEST IN-SITU OBSERVATIONS. 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 LEWITSKY