000 AGXX40 KNHC 231733 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 135 PM EDT SUN MAR 23 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A WEAK FRONTAL BOUNDARY LYING FROM S FL THROUGH THE EXTREME SERN GULF TO THE NE YUCATAN EARLY THIS AFTERNOON IS SLOWLY SINKING SE. A 1102 UTC QUIKSCAT PASS AS WELL AS BUOY...SHIP...AND CMAN DATA INDICATE WEAK N TO NE WINDS OF 10 TO 15 KT BEHIND THE FRONT FROM THE EAST CTRL TO THE SW GULF WHILE EVEN LIGHTER SW TO W 5 TO 10 KT WINDS LIE DIRECTLY AHEAD OF THE BOUNDARY. WITH WEAK WINDS BOTH YESTERDAY AND AGAIN TODAY...SEAS GENERALLY RANGE BETWEEN 2 AND 4 FT SE OF A LINE FROM 30N85W TO 25N90W TO 25N97W AS OF 17 UTC. SATELLITE IMAGERY AND RADAR STILL SHOW ISOLATED CONVECTIVE ACTIVITY PULSING NEAR OR AHEAD OF THE BOUNDARY...MAINLY W OF THE LOWER KEYS. SOME ADDITIONAL ISOLATED TO SCATTERED CELLS COULD FIRE UP ALONG THE FRONT THIS AFTERNOON AND EVENING...THOUGH WHATEVER FORMS SHOULD BE LIMITED SINCE THE MAIN DYNAMICS ARE ALREADY WELL NE OF THE AREA. ALTHOUGH FAIRLY TRANQUIL CONDITIONS CURRENTLY EXIST OVER THE SE HALF OF THE GULF...OBSERVATIONS SHOW A SECONDARY AND STRONGER FRONT... ABSENT ANY CLOUDS AND PRECIPITATION...RAPIDLY SURGING SE OVER THE NRN WATERS. WITH STRONG HIGH PRES BUILDING IN BEHIND THE FRONT FROM THE SRN PLAINS...BRISK N TO NE WINDS ARE RAPIDLY INCREASING FROM OFFSHORE THE TX COAST ENE TO THE WRN FL PANHANDLE. IN FACT...BUOY FGBL1 IN THE NW GULF HAS SUSTAINED NE 25 KT WINDS...NOT TO MENTION SEVERAL OTHER BUOY/CMAN STATION NEAR THE UPR TX COAST WHILE N TO NE 20 KT WINDS ARE PRESENT NEAR THE LA/MS COASTS. DATA FROM THESE STATIONS SHOW SHORT PERIOD WIND WAVES OF 4 TO 7 FT ALREADY IN A DEVELOPING NE SWELL...VALUES SEVERAL FEET LOWER THAN WAVEWATCH GUIDANCE IN SOME CASES. MODEL GUIDANCE INDICATES THAT THE SECONDARY FRONT SHOULD SWEEP THROUGH THE GULF TODAY THROUGH EARLY MON...IN RESPONSE TO A POTENT SHRTWV TROF OVER THE MIDWEST DIVING INTO THE SERN STATES BY MON NIGHT. A STRONG PRES GRADIENT BETWEEN THE FRONT AND AN EWD-SHIFTING SFC HIGH MIGRATING ACROSS THE SRN STATES WILL LEAD TO A BURST OF BRISK N TO NE WINDS OF 20 TO 25 KT SPREADING NW TO SE ACROSS THE GULF LATER TODAY THROUGH TUE MORNING. WAVEWATCH III OUTPUT SUGGESTS SEAS BUILDING TO 8 TO 12 FT IN NNE SWELL OVER A LARGE PART OF THE GULF...WITH SEAS PEAKING IN THE NW MON MORNING IN THE AFTERNOON FOR CENTRAL AREAS AND THEN TUE MORNING OVER THE FAR SE. THEREAFTER...A TRANSIENT NRN STREAM SHRTWV RACING OUT OF THE DAKOTAS TUE MORNING SHOULD FAIL TO AMPLIFY SIGNIFICANTLY AS IT HEAD TO THE NERN STATES LATE WED. THIS SHOULD KEEP A FLAT NEARLY ZONAL FLOW ACROSS THE GULF/SERN STATES AROUND MID-WEEK...WITH THE ORIGINAL SFC RIDGE CAMPING OUT NEAR OR JUST OFFSHORE THE SE CONUS COAST. UNDER THIS PATTERN...EXPECT AN E TO SE LOW-LVL FLOW OF 10 TO 15 KT GULF WIDE BY EARLY WED CONTINUING THROUGH THU...WHICH SHOULD INCREASE TO 15 TO 20 KT AND BECOME MORE SE TO S WEST OF 90W BY THU. AS IS TYPICALLY THE CASE UNDER A RETURN FLOW...MODEL GUIDANCE SHOWS THE POTENTIAL FOR SE TO S 20 TO 25 KT WINDS DIRECTLY IMMEDIATELY OFFSHORE THE S TX AND NERN MEXICAN COASTS LATER WED AND THU. THIS COULD KEEP WAVE HEIGHTS IN THE 5 TO 8 FT RANGE IN SE SWELL. OTHERWISE...SEAS ACROSS THE GULF SHOULD SUBSIDE TO 3 TO 6 FT AFTER THE EARLY WEEK WIND BURST...WITH SEAS 1 TO 3 FT OVER THE FAR NE GULF CLOSER TO THE CORE OF THE SFC HIGH. LATE WEEK...INDICATIONS ARE THAT BY A VIGOROUS SHRTWV PUSHING THROUGH THE CTRL/NRN ROCKIES THU SHOULD AMPLIFY AND TAKE A NE TRACK ACROSS THE NRN PLAINS BY FRI....WHILE A WELL-DEFINED SHRTWV RIDGE SETS UP SHOP OVER THE WRN ATLC. RIDGING IN THE SE APPEARS TO BE STRONG ENOUGH TO KEEP THE ASSOCIATED COLD FRONT FROM REACHING GULF WATERS THROUGH AT LEAST FRI. OUT OF THE GUIDANCE...THE ECMWF SUGGESTS THE FRONT MAY NEVER REACH THE GULF AND STALL OVER THE SRN STATES...WITH THE GFS/CMC/GFS ENSEMBLE MEAN INDICATING A FRONTAL PASSAGE SOMETIME SAT. NEVERTHELESS...WITH THE MAIN DYNAMICS WELL NORTH...THE LIKELIHOOD OF A WIND EVENT AGAIN OVER THE GULF SEEMS UNLIKELY LATE THIS WEEK INTO AT LEAST EARLY THIS WEEKEND. CARIBBEAN SEA... THE COLD FRONT OVER THE SERN GULF THIS MORNING SHOULD SLIP INTO THE NW WATERS THIS AFTERNOON...WITH THE SECONDARY PUSH DRIVING THE FRONT TO A WINDWARD PASSAGE/NE NICARAGUA LINE BY TUE MORNING WHERE THE FRONT STALLS. LIGHT NE TO E WINDS COVERING THE NW WATERS THIS MORNING SHOULD BEGIN INCREASING MON MIDDAY...WITH N WINDS 20 TO 25 KT N OF 20N W OF 84W BY MON EVENING AND SEA BUILDING TO 11 FT IN THE YUCATAN CHANNEL. WINDS SHOULD CONTINUE TO MATURE...WITH A LARGE SWATH OF NE 20 TO 25 KT WINDS EXPECTED GENERALLY NW OF A LINE FROM 16N85W TO 20N78W. AS WINDS PEAK TUE...WAVE HEIGHTS SHOULD BUILD TO 6 TO 10 FT. ALTHOUGH THE STALLED FRONT SHOULD BEGIN WEAKENING LATER TUE...THE STRONG SFC HIGH TO THE N SHOULD KEEP BRISK NE WINDS THROUGH AT LEAST LATE WED BEFORE GRADUALLY DIMINISHING. THIS SHOULD KEEP SEAS OF 6 TO 9 FT IN NE SWELL ACROSS THE AREA...DIMINISHING TO 5 TO 8 FT BY THU. ELSEWHERE...MODERATELY STRONG TRADES ACROSS THE REMAINDER OF THE BASIN SHOULD REMAIN ABOUT THE SAME THROUGH TUE...WITH SEAS GENERALLY 5 TO 8 FT IN E SWELL. TYPICALLY HIGHER WINDS 20 TO 25 KT WINDS SHOULD PERSIST OFF THE COLOMBIA COAST...WITH SEAS RANGING FROM 8 TO 11 FT. HOWEVER...ALL MODELS SHOW THE STRONG RIDGE MOVING ACRS THE SRN STATES EARLY THIS WEEK CAMPING OUT OFF THE SE CONUS COAST FROM MID-WEEK THROUGH LATE WEEK. THIS PATTERN SHOULD FAVOR FRESH TRADES ACROSS MUCH OF THE BASIN...WITH SEAS BUILDING TO 6 TO 9 FT IN E SWELL. THERE LIKELY WILL ALSO BE AN OPTIMAL PERIOD BETWEEN WED AND EARLY THU WHEN A BRISK NE FLOW INTO THE ATLC PASSAGES WILL FAVOR FUNNELING OF THE WIND. WINDS SHOULD ALSO PICK UP TO 25-30 KT ALONG THE COLOMBIAN COAST...WITH SEAS 9 TO 13 FT IN NE SWELL. FINALLY...A GALE EVENT IN THE SW ATLC EARLY THIS WEEK SHOULD DELIVER 8 TO 11 FT NLY SWELL TO THE NRN COASTS OF HISPANIOLA...PUERTO RICO...AND THE NRN ANTILLES THU AFTERNOON...WITH AROUND 10 FT SWELL TRAVELING SE INTO THE REMAINDER OF THE ANTILLES BY FRI. SW ATLANTIC... THE WEAK FRONT LYING ACROSS THE SE GULF AND FL EXTENDS FARTHER NE TO NEAR 31N68W LATE THIS MORNING AND IS ESSENTIALLY STATIONARY OVER THE SW ATLC. SCATTERED CONVECTIVE ACTIVITY CONTINUES TO FORM ALONG THE BOUNDARY BUT IS MOST CONCENTRATED NEAR AND DIRECTLY AHEAD OF A WEAK SFC WAVE MOVING OFF THE E CENTRAL FL COAST. DESPITE THIS...WINDS ARE FAIRLY WEAK OUTSIDE OF CONVECTIVE AREAS...WITH NE TO E WINDS OF 10 TO 15 KT N OF THE BOUNDARY AND A S TO SW FLOW OF 10 TO 15 KT AHEAD OF THE BOUNDARY. OTHERWISE...A GENERAL SE TO S WIND OF 10 TO 15 KT COVERS THE REMAINDER OF THE AREA...WITH 4 TO 8 FT SEAS E OF THE BAHAMAS IN NE TO E SWELL AND TO 2 TO 4 FT SEAS W OF THE BAHAMAS. LITTLE CHANGE TO THESE CONDITIONS ARE ANTICIPATED THROUGH EARLY MON MORNING. THEREAFTER...A SHRTWV OVER THE MIDWEST IS FORECAST TO DIG INTO THE SERN STATES BY MON NIGHT...WHICH SHOULD USHER IN A REINFORCING COLD FRONT MON AND TUE. STRONG UPR-LVL DIVERGENCE/PVA ASSOCIATED WITH THE SHRTWV/LOCAL CONVECTIVE ACTIVITY AND HEATING SHOULD CAUSE THE WEAK SFC WAVE OVER THE NW BAHAMAS EARLY MON MORNING TO BEGIN STRENGTHEN- ING AS A TAKES A ROUTE NE OF THE AREA BY MON AFTERNOON. THE GRADIENT BETWEEN INTENSIFYING LOW PRES OVER THE CAROLINA COAST AND STRONG HIGH PRES BEHIND THE FRONT SHOULD LEAD TO NW TO N 20 TO 30 KT WINDS NW OF THE FRONT BEGINNING MON EVENING/NIGHT...WITH WINDS INCREASING TO GALE FORCE OVER N CTRL/NE WATERS TUE MORNING AND AFTERNOON. INTERESTINGLY...THE LAST SEVERAL RUNS OF THE OPERATIONAL GFS HAVE CONSISTENTLY PREDICTED GALE FORCE CONDITIONS N OF ABOUT 30N AND E OF 74W AROUND THIS TIME WHILE ENSEMBLE PROBABILITIES HAVE CONSISTENTLY SHOWN LITTLE..IF ANY...CHANCE OF THIS. BOTH THE 06Z AND 12Z GFS HAVE ALSO COME IN STRONGER WITH GALE CONDITIONS...INDICATING THE POTENTIAL FOR 40 KT WINDS RIGHT AT 31N E OF 72W. IT IS WORTH NOTING THAT THE GFS CONTINUES TO BE SLIGHTLY SHARPER W/ THE SHRTWV DIGGING OVER THE SERN STATES...EVEN SHARPER THAN THE CANADIAN GEM. THIS COULD ACCOUNT FOR THE STRONGER WINDS EVIDENT IN THE GFS. HOWEVER... GIVEN THE TRENDS IN THE OPERATIONAL GFS...AM RELUCTANT TO DISCONTINUE THE GALE WARNING AT THIS POINT AND WILL HOLD ONTO IT FOR NOW. RIGHT AFTER THE WINDS PICK...SEAS BEGIN TO RESPOND IN KIND...BUILDING TO 10 TO 15 FT IN NW SWELL W OF THE FRONT TO N OF THE BAHAMAS TUE MORNING. SEAS MATURE TO 10 TO 18 FT N OF 26N E OF 77W TUE EVENING ...AROUND THE TIME WINDS BEGIN TO DECREASE OVER THE FAR NW WATERS. GOING INTO WED...THE FRONT SHOULD STALL OVER SE WATERS...BUT BRISK NE WINDS SHOULD CONTINUE WITHIN ABOUT 300 NM NW OF IT THROUGH AT LEAST EARLY THU. MOREOVER...10 TO 16 FT NLY SWELL SHOULD BE PROPAGATING AWAY FROM ITS SOURCE REGION...SETTING THEIR SIGHTS ON THE NRN CARIBBEAN. WAVEWATCH III SHOWS WHAT SEEMS TO BE A NEARLY CONTINUAL SUPPLY OF ADDITIONAL SWELL PROPAGATING AWAY FROM THE GALE/STORM CENTER OVER THE N ATLC WED...WITH 8 TO 13 FT SEAS STILL PRESENT OVER THE ERN HALF OF THE AREA INTO THU. OUTSIDE OF THE AFTERMATH OF THE GALE EARLY IN THE WEEK...MODELS SHOW SHRTWV RIDGING DOMINATING THE WRN ATLC LATE IN THE WEEK. THIS SHOULD KEEP A MODERATE TO SOMETIMES FRESH ELY FLOW ACROSS THE REGION...WHICH COULD VEER MORE SE TO S BY FRI OVER WRN WATERS. LONG PERIOD NE SWELL SHOULD BE SLOW TO FADE AWAY...WITH 8 TO 9 FT SEAS STILL OVER THE SE PART OF THE AREA INTO LATE FRI. WARNINGS... ATLC... GALE WARNING...AMZ080 CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER KIMBERLAIN