000 AGXX40 KNHC 040729 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 330 AM EDT SUN JUL 04 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC FROM 07N TO 22N BETWEEN 55W AND 65W...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... THE ASCAT PASS FROM 0242 UTC SHOWED 20-25 KT WINDS WITHIN 75 NM N SEMICIRCLE OF THE LOW PRES CENTER IN THE N CENTRAL GULF AND THERE WERE SEVERAL OBSERVATIONS THAT SUPPORTED THIS INTENSITY...BUT MOST OF THESE WERE OBSERVATIONS WERE FROM STATIONS OF EITHER UNKNOWN ANEMOMETER HEIGHT OR A HEIGHT ABOVE 30 METERS. THE ASCAT PASS SHOWED A BROAD LOW LEVEL CENTER WITH WINDS 15 KT OR LESS IN THE S SEMICIRCLE. THE EXPOSED LOW LEVEL CENTER WAS EASILY IDENTIFIABLE IN THE NIGHT CHANNEL SATELLITE IMAGERY...WITH THE BULK OF THE DEEP CONVECTION WELL TO THE E OF CENTER. AT 0600 UTC...THE 1011 MB LOW WAS ANALYZED NEAR 27N90W AND WAS MOVING W-SW AT 8 KT. THE MODELS HAVE SWUNG BACK TO THE E WITH THE TRACK OF THE LOW CENTER OVER THE NEXT DAY OR SO...MOVING THE SYSTEM ONSHORE MORE QUICKLY. THE MODEL CONSENSUS TAKES THE LOW INTO SE LOUISIANA OVERNIGHT SUN NIGHT AND DISSIPATE IT BY MON NIGHT. WAVE HEIGHT OBSERVATIONS ARE SOMEWHAT SPARSE IN THE AREA OF STRONGEST WINDS...BUT BELIEVED TO BE IN THE 7-8 FT RANGE WITHIN THE REGIONS WHERE THERE IS NO OIL OVER THE WATER TO INHIBIT THE PRODUCTION OF WIND WAVES BASED ON MODEL GUIDANCE. THE LOW LEVEL BOUNDARY THAT EXTENDS E FROM THE LOW IS EXPECTED TO DISSIPATE OVER FLORIDA TODAY...LEAVING A WARM FRONT TO CREEP NORTHWARD WITH THE LOW INTO THE NE AND CENTRAL GULF COAST. THIS WARM FRONT WILL BE THE FOCUS OF PRECIPITATION OVER AS THE SYSTEM LIFTS NORTH-NORTHWESTWARD AND MOVES INLAND. LATER IN THE PERIOD...THE MODELS GENERALLY AGREE ON MOVING THE NORTHERN PORTION OF A TROPICAL WAVE INTO THE S CENTRAL AND SW GULF OF MEXICO LATE MON THROUGH THE END OF THE PERIOD ON THU. THE ECMWF...WHICH HAD TRENDED AWAY FROM A CLOSED LOW-LEVEL WIND FIELD WITH THE LOW LAST NIGHT...HAS NOW ADOPTED ONE OF THE STRONGEST SOLUTIONS. IT CARRIES A 1005 MB LOW OVER THE SW GULF NEAR 23N96W BY THU AFTERNOON WITH THE OPERATIONAL GFS VERY CLOSE TO ITS POSITION...BUT ONLY 1009 MB. ASIDE FROM THE CMC...THE OTHER MODELS CARRY AN OPEN WAVE AT THAT TIME. THIS INCLUDES THE PARALLEL GFS. THE OPERATIONAL GFS APPEARS TO DRAW THE NORTHERN VORT ENERGY ASSOCIATED WITH THE TROPICAL WAVE INTO A WEAK MID LEVEL TROUGH INDUCED BY THE LOW CURRENTLY IN THE N CENTRAL GULF. THIS ENERGY SLOWLY BREAKS AWAY FROM THE WEAKENING TROUGH WHICH ALLOWS THE LINGERING MID LEVEL ENERGY TO INTENSIFY OVER THE WESTERN GULF. THE GFS CARRIES STRONG SOUTHERLY SURFACE FLOW INTO THE CENTRAL GULF AS A RESULT OF THIS PATTERN AND IT APPEARS TO BE AN OUTLIER. THE PARALLEL GFS AGREES MORE WITH THE ECMWF WHICH KEEPS THE ENERGY ASSOCIATED WITH THE WAVE SEPARATE FROM THE SYSTEM CURRENTLY IN THE N CENTRAL GULF. HOWEVER...THE GFS PARALLEL IS NOT AS KEEN ON DEVELOPING A CLOSED LOW LEVEL CIRCULATION. FOR NOW...THE FORECAST RELIES ON A BLEND OF THE 00Z GFS PARALLEL AND ECMWF. THIS CALLS FOR A 1006 MB LOW PRES SYSTEM IN THE SW GULF TUE NIGHT THAT SLOWLY MOVES W TOWARD THE COAST THROUGH THU WITH LITTLE CHANGE IN INTENSITY. THE PRES GRADIENT ON THE NE SIDE OF THE LOW BETWEEN IT AND THE HIGH PRES OVER THE NE GULF SHOULD BE TIGHT ENOUGH TO ALLOW FOR 25 KT WINDS. SW N ATLC... A WEAK FRONT STRETCHES FROM 27N65W TO CAPE CANAVERAL WITH WINDS LESS THAN 20 KT NEAR THE FRONT. THE PORTION OF THE FRONT E OF 70W WILL SLOWLY PULL E OUT OF THE AREA WHILE THE REMNANTS OF THE BOUNDARY W OF 70W DIMINISH TO A TROUGH AND PASS NE THROUGH THE NORTHERN BAHAMAS AND TO THE FL COAST. THE OPERATIONAL GFS HAS TRENDED TOWARD A WEAKER SYSTEMS THAN THE RUN LAST NIGHT AT 00Z. IT NOW ONLY BRIEFLY CLOSES OFF A LOW LEVEL CIRCULATION AND IT IS IN BETTER AGREEMENT WITH THE TRACK OF THE TROUGH TOWARD FLORIDA. WINDS ARE NOW ONLY TO 20 KT WITH THE TROUGH. THIS SEEMS REASONABLE COMPARED TO THE OTHER MODELS. CARIBBEAN SEA AND TROPICAL ATLC... A TROPICAL WAVE IS ALONG 82W S OF 18W. WINDS AT BUOY 42057 TOOK A DECIDEDLY SOUTH TURN AS THE WAVE PASSED THROUGH. WINDS THERE ARE CURRENTLY 21N KT WITH 8 FT SEAS. AN AREA OF NUMEROUS MODERATE CONVECTION ASSOCIATED WILL AN INCREASINGLY BETTER DEFINED MID LEVEL CENTER LIES E OF THE WAVE FROM JAMAICA S TO 15N. AN ASCAT PASS FROM 0238 UTC CAPTURED AN AREA OF 20-25 KT WELL E OF THE WAVE IN THE CENTRAL CARIBBEAN BETWEEN 70W AND 75W. THE LARGE AREA OF 20-25 KT WINDS ASSOCIATED WITH THIS WAVE WILL TREK NW THROUGH THE WESTERN CARIBBEAN INTO TUE. AS EXPLAINED IN THE GULF OF MEXICO SECTION...THE PREFERRED SOLUTION AS THE WAVE MOVES FROM THE CARIBBEAN INTO THE GULF IS IN LINE WITH A BLEND OF THE 00Z ECMWF AND GFS PARALLEL. HOWEVER...THE OPERATIONAL GFS IS COMING INTO BETTER AGREEMENT WITH THE PREFERRED SOLUTION AS IT HAS BACKED OFF ON THE GALE FORCE WINDS ITS RUN FROM LAST NIGHT HAD DEVELOPED E OF THE WAVE. HIGHEST SEAS ARE FORECAST TO BE IN THE RANGE OF 8 TO 12 FT WITH WINDS TO 30 KT...NOT MUCH STRONGER THAN WHAT IS ALREADY BEING EXPERIENCED NEAR THE WAVE. THE NEXT WAVE IS CURRENTLY PASSING THROUGH THE TROPICAL N ATLC ZONE LATER AND WILL MOVE INTO THE EASTERN CARIBBEAN BY MON...REACHING THE CENTRAL CARIBBEAN TUE AND WED AND MOVE INTO THE WESTERN CARIBBEAN BY THU. AS IT DOES...IT WILL ENHANCE NE TO E TRADES. CONFIDENCE BECOMES LOWER IN THE TIMING AND STRENGTH OF THE WINDS WITH THIS WAVE BY WED/THU WHEN THE DEPTH OF THE TROUGHING IN THE GULF OF MEXICO MAY BEGIN TO IMPACT THE WAVE. RELIED MORE HEAVILY ON THE FAVORED GFS PARALLEL/ECMWF BLEND AT THAT TIME. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. 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