000 AGXX40 KNHC 130627 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 230 AM EDT THU MAR 13 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE COLD FRONT HAS CLEARED THE FAR SE PORTION OF THE GULF WITH 1019 MB SFC HIGH OVER THE N-CENTRAL PORTIONS IN CONTROL OF THE WEATHER ATTM. LIGHT SE RETURN FLOW IS OCCURRING MOST AREAS W OF 90W. HIGH PRESS MOVES EWD TODAY AND E OF THE GULF BY LATE TONIGHT EARLY FRI. RETURN FLOW INCREASES TO 15-20 KT MOST AREAS W OF 90W LATER TODAY AND TONIGHT AND TURNS MORE TO S TO SW ON FRI AS THE AREA OF WINDS SPREADS EWD ACROSS THE N PORTIONS OF THE GULF. THE GFS HAS BACKED OFF ON INCREASING THE WINDS TO 20-25 KT ON FRI AND DELAYS THE ONSET OF 20-25 KT WINDS UNTIL SAT. THIS IS MORE IN LINE WITH THE OTHER GLOBAL MODELS AND WILL THEREFORE CUT WINDS DOWN A TAD ON FRI. AS FOR THE NEXT COLD FRONT SLATED TO MOVE INTO THE GULF...THE MODELS ARE IN OVERALL AGREEMENT IN THE TIMING THE FRONT INDICATING IT MOVING OFF THE TEXAS COAST LATE SAT...ONCE AGAIN THE GFS IS ABOUT 6 HOURS OR SO FASTER THAN THE MORE CONSISTENT UKMET/ECMWF/GFS ENSEMBLE MEAN. WILL THEREFORE LEAN TOWARD THE MAJORITY AND BRING THE FRONT OFF LATE SAT. GFS IS THE MOST ROBUST IN DEPICTING NE WINDS OF 20-25 KT BEHIND THE FRONT WHILE THE OTHER MODELS ARE A TAD LOWER. WILL LEAN TOWARD THE GFS BETTER DEPICTION OF 10-M WINDS FOR NOW. THE FRONT MOVES SWD TO ALONG 28N. CANADIAN HIGH MOVES EWD BRIDGES THE FRONT AND STRENGTHENS AS LOW PRESS DEVELOPS OVER THE PLAINS. THE RESULTING PRESS GRADIENT ALLOWS WINDS TO VEER TO THE E AND SE AND INCREASE TO 20-25 KT OVER THE NW GULF ZONE BY LATE SUN AND SPREAD OVER MOST OF THE GULF ON MON. SW N ATLC... A COLD FRONT EXTENDS FROM 31N70W TO A SMALL AREA OF LOW PRESS JUST OFF THE SE FLORIDA COAST BETWEEN STUART AND GRAND BAHAMA ISLAND. THIS EVENINGS QUIKSCAT PASS SHOWED NW WINDS HAVE DROPPED OFF MARKEDLY W OF THE FRONT AS HIGH PRESS BUILDS IN. THE FRONT SWEEPS EWD RAPIDLY WEAKENS AND EXTENDS FROM 28N65W TO 26N75W. LOW PRESS OFF THE FLORIDA COAST RIDES ALONG THE FRONT AND MOVES E OF THE AREA TONIGHT. GFS CRANKS UP A SPURIOUS AREA OF 20-25 KT WINDS AROUND THE LOW IN RESPONSE TO CONVECTIVE FEEDBACK WHICH INCREASES AS THE DAY PROGRESSES PER 7H OMEGA FIELDS. WILL DISCOUNT THIS SOLUTION AND OPT FOR A MORE SMOOTHED WIND FIELD OF 15 KT. IN ANY EVENT HIGH PRES QUICKLY BUILDS E THROUGH FRI AND JUST E OF THE REGION BY FRI NIGHT. THE INCREASE IN THE SLY RETURN FLOW IS EXPECTED TO BEGIN ON SAT OVER THE FAR NW PORTION IN ADVANCE OF A STORM SYSTEM OVER THE CENTRAL AND EASTERN U.S. THE ASSOCIATED COLD FRONT IS FORECAST TO MOVE INTO THE AREA LATE SAT NIGHT AND EXTEND FROM 31N65W TO SE FLORIDA BY LATE SUN IN LINE WITH THE GFS WHICH IS A COMPROMISE BETWEEN THE MUCH FASTER CMC/ECMWF SOLUTIONS AND SLOWER UKMET. OVERALL MID AND UPPER TROUGH AMPLIFIES MARKEDLY ON SUN E OF 70W. IN RESPONSE MODELS ARE ALL IN AGREEMENT IN INCREASING SW WINDS AHEAD OF THE FRONT TO 25 TO 30 KT OVER THE FAR NE WATERS. NW WINDS REMAIN AT 20 TO 30 KT BEHIND THE FRONT. THE FRONT DIVES SWD AND EXTENDS FROM 22N65W TO E-CENTRAL CUBA BY LATE MON AND IN CONJUNCTION WITH STRONG CANADIAN HIGH PRES BUILDING SE IN ITS WAKE. THE ASSOCIATED TIGHT PRES GRADIENT BETWEEN THE SYNOPTIC FEATURES WILL PRODUCE STRONG NE TO E WINDS ACROSS MOST OF THE AREA. CARIBBEAN AND TROPICAL N ATLC... THIS EVENINGS QSCAT PASS SHOWED AN AREA OF 20-25 KT NE WINDS NEAR THE COAST OF COLOMBIA...SLIGHTLY LOWER THAN 24 HOURS AGO. QSCAT DATA ALSO SHOWED MAINLY 15-20 KT TRADES ELSEWHERE S OF 16N BETWEEN 70W-80W AND 10-15 KT OVER THE REMAINDER OF THE REGION. OVERALL...LITTLE CHANGES ARE EXPECTED UNTIL FRI NIGHT AND SAT WHEN SE FLOW DEVELOPS OVER THE NW PORTION IN RESPONSE TO A STORM SYSTEM AND FRONTAL BOUNDARY OVER THE CENTRAL AND EASTERN CONUS. A SUPPRESSED RIDGE AHEAD OF THE COLD FRONT KEEPS SUBNORMAL TRADES THROUGH SUN OVER MOST OF THE AREA WITH THE EXCEPTION OF THE FAR SW CARIBBEAN WHERE 20-25 KT WINDS REMAIN. BY MON...STRONG CANADIAN HIGH PRES BUILDS INCREASING TRADES ACROSS MOST OF THE CARIBBEAN W OF 70W. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER COBB