000 AGXX40 KNHC 051923 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 PM EST MON DEC 05 2011 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... THE RIDGE OVER THE GULF OF MEXICO HAS STARTED TO SHIFT SLOWLY EASTWARD AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE FAR NW GULF. SURFACE DATA AND THE MOST RECENT ASCAT PASS INDICATE MODERATE TO FRESH SE TO S WINDS AHEAD OF THE FRONT WITH NW TO N WINDS OF 15 TO 20 KT BEHIND THE FRONT. THIS SYSTEM WILL BEGIN TO MOVE SE AS A COLD FRONT LATER TODAY REACHING FROM SE LOUISIANA TO TAMPICO MEXICO TONIGHT AND FROM MOBILE ALABAMA TO WESTERN BAY OF CAMPECHE TUE NIGHT. EXPECT INCREASING WINDS IN THE 20 TO 30 KT RANGE AND BUILDING SEAS OF UP TO 11 FT IN THE WAKE OF THE FRONT. THIS FEATURE WILL BRIEFLY STALL WED. A REINFORCING FRONT WILL HELP PUSH THE FIRST FRONT EWD ACROSS THE REST OF THE GULF WATERS THU AND SE OF THE AREA BY LATE THU/EARLY FRI. WINDS ARE EXPECTED TO DIMINISH THU NIGHT AND FRI ACROSS MUCH OF THE REGION. HOWEVER...CURRENT INDICATIONS ARE THAT WINDS WILL INCREASE AGAIN OVER THE FAR WESTERN GULF BY FRI AS HIGH PRES BUILDS ACROSS THE EASTERN SLOPE OF THE SIERRA MADRE MOUNTAINS. MARINE GUIDANCE SUGGESTS A 1033 MB HIGH PRES OVER NW TEXAS ON THIS DAY. CARIBBEAN SEA AND TROPICAL N ATLC... THE PRESSURE GRADIENT BETWEEN STRONG HIGH PRESSURE RIDGE N OF THE AREA AND LOW PRESSURE ASSOCIATED WITH THE MONSOON TROUGH OVER THE SW CARIBBEAN IS SUPPORTING FRESH NE WINDS OVER MUCH OF THE BASIN W OF 70W AS INDICATED BY SCATTEROMETER PASSES AND SURFACE DATA. THE CONTINUED FRESH TO STRONG WINDS HAVE RESULTED IN SEAS TO 8 N OF 18N...INCLUDING THE WINDWARD PASSAGE AND NEAR THE COAST OF COLOMBIA. THE HIGH PRESSURE RIDGE WILL WEAKEN TODAY AND TUE RESULTING IN DIMINISHING WINDS ACROSS THE AREA. A WEAKENING COLD FRONT WILL ENTER THE FAR NW CARIBBEAN THU EVENING AND FRI WITH A FRESHENING OF NLY WINDS. ACTIVE WEATHER CONTINUES OVER THE N PORTION OF THE TROPICAL N ATLC AND FAR E CARIBBEAN WATERS AS A RESULT OF A STATIONARY SURFACE TROUGH. SCATTERED SHOWERS AND TSTMS ARE NOTED MAINLY E OF THE TROUGH OVER THE NE PART OF THE TROPICAL N ATLC. WINDS AND SEAS WILL BE HIGHER NEAR THE TSTMS. AS THE UPPER LEVEL TROUGH SUPPORTING THIS LOW LEVEL FEATURE SHIFTS E TODAY AND TUE...THE WEAK LOW LEVEL TROUGHING WILL DRIFT W AND AND GRADUALLY DISSIPATE BY TUE. CURRENTLY...PRES GRADIENT BETWEEN THIS TROUGH AND STRONG HIGH PRES TO THE N IS PRODUCING AN AREA OF GALE FORCE WINDS OVER FORECAST WATERS N OF 27N BETWEEN 60W AND 69W. THESE WINDS ARE FORECAST TO DIMINISH BELOW GALE FORCE THIS EVENING. ANOTHER TROUGH MAY DEVELOP OVER THE TROPICAL N ATLC WATERS TUE. FOR NOW...THE FORECAST INDICATES WINDS OF 20 TO 25 KT IN ASSOCIATION WITH THIS NEW TROUGH. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... A 1033 MB HIGH LOCATED N OF AREA NEAR 41N62W EXTENDS A RIDGE SW ACROSS THE SW N ATLC AND FLORIDA INTO THE GULF OF MEXICO. A SURFACE TROUGH REMAINS JUST E OF THE ZONE ALONG 62W FROM 18N TO 27N. PRES GRADIENT BETWEEN THESE TWO FEATURES IS PRODUCING AN AREA OF GALE FORCE WINDS N OF 27N E OF 69W. THE 1426 UTC ASCAT PASS REVELED 30 KT WINDS OVER THE FAR NE PART OF THE AREA...BUT HAVING IN ACCOUNT THE LOW BIAS OF THE ASCAT DERIVED WINDS... DECIDE TO KEEP A GALE WARNING N OF 27N E OF 69W THROUGH THIS EVENING. LATEST JASON ALTIMETER PASS ALSO INDICATES SEAS TO 16 FT AS A RESULT OF THE CONTINUED STRONG NE WINDS. THE HIGH PRESSURE CENTER AND TROUGH WILL START TO WEAKEN LATER TODAY... AND WINDS WILL DIMINISH BELOW GALE FORCE. WINDS WILL DIMINISH FURTHER THROUGH THE WEEK AS THE HIGH PRESSURE CENTER AND ASSOCIATED RIDGE WILL SHIFT S INTO THE AREA BY MIDWEEK. SEAS WILL ALSO SLOWLY SUBSIDE...TO BELOW 10 FT BY THU. FRESH SOUTHERLY FLOW ON THE WESTERN PERIPHERY OF THE RIDGE WILL INCREASE OVER THE NW PART OF THE AREA LATE WED/EARLY THU AHEAD OF A COLD FRONT WHICH WILL MOVE OFF THE SE COAST OF U.S. EARLY THU MORNING. THE FRONT WILL EXTEND FROM 31N76W ACROSS THE STRAITS OF FLORIDA TO THE YUCATAN PENINSULA THU MORNING...FROM 30N70W TO CENTRAL CUBA THU NIGHT THEN STALL BY FRI AND LIKELY MOVE BACK LATE FRI. WARNINGS... GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .AMZ080...GALE WARNING N OF 27N E OF 69W... FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER GR/AL