000 AGXX40 KNHC 200808 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 308 AM EST SAT FEB 20 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... S/W TROUGH EMBEDDED IN THE FAST MOVING UPPER LEVEL FLOW HAS MOVED E TO ALONG 90W THIS MORNING...HELPING TO NUDGE THE SURFACE HIGH TO ACROSS N CENTRAL FLORIDA. RECENT SCATTEROMETER PASSES... AND EXITING HIGH CLOUDS...REVEAL A 1014 MB LOW ACROSS THE WRN GULF NEAR 24N94W WITH DEVELOPING WARM FRONT EXTENDING E TO NEAR 90W. SCATTEROMETER DATA ALSO INDICATES A NARROW AND ELONGATED BAND OF 20-30 KT WINDS TO THE N OF THE WARM FRONT AND LOW...AS FORECAST BY THE MODELS PAST FEW DAYS. AN E TO E-SE FLOW OF 15 KT PREVAILS ELSEWHERE ACROSS THE GULF N OF 24N...AND ELY NEAR 20 KT S OF 24N E OF 90W. BUOY 42002 HAS BEEN FLUCTUATING 10-11 FT PAST FEW HOURS...LOCATED WITHIN THE BAND OF STRONGEST WINDS. A STRONG AND SEEP LAYERED MIDDLE-UPPER LEVEL LOW ACROSS THE WRN U.S. WILL SHIFT E-SE NEXT 24 HOURS...AND SUPPORT THE DEVELOPMENT OF A SURFACE LOW ACROSS N TEXAS-OK SUN...WHICH WILL THEN MOVE NE ACROSS THE MS VALLEY AND INTO THE ERN U.S. SUN-MON...AND DRAG A COLD FRONT INTO THE NW GULF SUN AFTERNOON/EVENING. THE FRONT IS FORECAST TO MOVE VERY QUICKLY ACROSS THE GULF AND REACH A PSN FROM NEAR MOBILE ALABAMA TO WESTERN BAY OF CAMPECHE MON AFTERNOON...AND THEN E OF THE FLORIDA PENINSULA SW TO NW CUBA AND THE NRN YUCATAN BY NOON TUE. LATEST MODEL GUIDANCE INDICATES THAT THE FRONT WILL NOT BE AS STRONG COMPARED TO RECENT BOUNDARIES. STRONGEST WINDS AND HIGHEST SEAS ARE EXPECTED TO OCCUR N OF THE WARM FRONT CURRENTLY ACROSS THE WRN GULF...WITH WINDS 20-25 KT AND SEAS TO 8 FT. THESE WINDS WILL SHIFT N AHEAD OF THE WARM FRONT AS IT LIFTS GRADUALLY N AND NE THROUGH SUN MORNING. THE ECMWF THEN SHOWS 20-25 KT OF SLY FLOW ACROSS THE ERN GULF AHEAD OF THE COLD FRONT MON MORNING...WHICH IS ALSO SUGGESTED TO SOME DEGREE BY THE GFS. MODELS SHOW WINDS VEERING VERY QUICKLY FROM N TO NE TO E-NE BEHIND THE FRONT...IN ABOUT 24 HOURS...AS IT MOVES QUICKLY ACROSS THE GULF. THIS WILL NOT ALLOW FOR SIGNIFICANT WAVE GROWTH ACROSS THE BASIN...AND SEAS ARE NOT FORECAST OVER 5 FT BASED ON THIS. CARIBBEAN SEA... WEAKENING FRONTAL BOUNDARY STRETCHED FROM CENTRAL ATLC SW ACROSS THE EXTREME NE CARIB...THROUGH THE VIRGIN ISLANDS...TO NEAR 15N75W. SCATTERED HEAVY SHOWERS WERE INDICATED ALONG THIS STALLED BOUNDARY S OF PUERTO RICO BY THE SAN JUAN 88D RADAR...WITH SIMILAR ACTIVITY LIKELY EXTENDING ALONG THE BOUNDARY TO JUST BEYOND ANGUILLA AND ST MARTEEN. A 0212 UTC ASCAT PASS SHOWED NELY WINDS OF 20-25 KT FUNNELING THROUGH THE MONA PASSAGE N OF THE FRONT AND LIKELY ACCELERATED BEYOND 70W AS IT TYPICAL WITH THIS TYPE OF PATTERN. ALSO INDICATED BY THIS ASCAT PASS WERE A BROAD ZONE OF CYCLONICALLY TURNING 20-25 KT WINDS OFF THE COAST OF COLOMBIA...WITH A SMALL AREA TO 30 KT JUST OFFSHORE OF THE COAST. THESE WINDS WILL SLOWLY DIMINISH THROUGH THE WEEKEND AS THE RIDGE OVER FL SLIDES E AND WEAKENS...LEAVING THE STRONGEST FLOW CONFINED TO THE SW CARIB OFF OF COLOMBIA. MEANWHILE...MODERATE TRADES ACROSS THE NE CARIBBEAN WILL INCREASE TO NEAR 20 KT AND SHIFT SE SUN THROUGH WED. THE WEAK COLD FRONT PASSING THROUGH THE GULF MON IS EXPECTED TO GRADUALLY DISSIPATE AFTER IT REACHES THE YUCATAN CHANNEL TUE. SW N ATLC AND TROPICAL ATLC W OF 55W... LARGE LOW PRES SYSTEM ACROSS THE NW ATLC EXTENDS INTO FAR N PORTIONS OF THE FORECAST AREA...WHERE EVENING SCATTEROMETER PASSES SHOWED W WINDS TO 30 KT N OF 30N E OF 63W. THIS PATTERN CONTINUES TO GENERATE NWLY SWELL AIMED TOWARD THE CENTRAL ATLANTIC...AND LARGE SEAS ARE NOT PROPAGATING INTO THE CARIBBEAN ISLANDS AND ADJACENT WATERS AS PER RECENT FRONTAL SYSTEMS. HOWEVER...A BRIEF PULSE OF MODERATE NWLY SWELL HAS HIT THE NE CARIBBEAN REGION IN THE PAST 24 HOURS...AND IS JUST BEGINNING TO SLOWLY FADE. COMBINED SEAS ACROSS THIS AREA WERE RUNNING 7 TO 10 FT AT 0800 UTC AND WILL BEGIN TO SLOWLY SUBSIDE. FARTHER N IN THE STRONGEST 30 KT WLY FLOW...WAVEWATCH GUIDANCE WAS INDICATING 16-18 FT SEAS..WITH ISOLATED BUOYS OBS JUST TO THE S OF THE AREA SUGGESTING THAT THIS MAY BE A FEW FEET HIGH. WINDS AND SEAS WILL GRADUALLY DISSIPATE AS LOW LIFTS OUT AND NEXT S/W MOVE DUE E ACROSS THE W ATLC. W OF 70W...WINDS ARE LIGHT AND VARIABLE N OF 23N BUT ACCELERATE TO 15-20 KT ALONG THE COAST OF CUBA AND THROUGH THE WINDWARD PASSAGE AS SUGGESTED BY THE 0212 UTC ASCAT PASS. THE NEXT GULF OF MEXICO FRONT IS EXPECTED TO REACH FROM NEAR 31N75W TO CENTRAL BAHAMAS TUE AFTERNOON AS THE HIGH RETREATS E OF THE AREA MON. THE MODELS AGREE ON DEVELOPING A SURFACE WAVE ALONG THE FRONT...WITH THE ECMWF CONSIDERABLY STRONGER THAN THE GFS...DEVELOPING A 1004 MB LOW PRES SYSTEMS NEAR 25N66W TUE EVENING. THIS APPEARS TO BE OVERDONE...BUT THE MODEL CONSENSUS IS FOR A MORE EASTERLY SOLUTION THAN THE GFS. 25 KT SOUTHERLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUE BEFORE IT MOVES OUT OF THE FORECAST AREA. THE NEXT FRONT QUICKLY MOVES OFF THE N FL COAST WED WITH THE GFS ON THE STRONG END OF THE GUIDANCE WITH THIS SYSTEM AS EXPLAINED IN THE GULF OF MEXICO SECTION. THE SLY WINDS AHEAD OF THE FRONT ARE EXPECTED TO INCREASE TO 20-30 KT LATE MON AFTERNOON/EVENING...AND THEN SHIFT W TO NW 15-20 KT BEHIND IT ON TUE. LATEST WAVEWATCH GUIDANCE SHOWS SEAS BUILDING UP TO 8 FT N OF 29N AHEAD OF THE FRONT. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING