000 AGXX40 KNHC 041902 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 302 PM EDT SAT SEP 04 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... WEAK FRONTAL BOUNDARY HAS DROPPED INTO THE FAR N GULF IN THE FORM OF A FINE LINE WITH DRY STABLE AIR BEHIND IT. LINGERING TROUGH ACROSS THE NE GULF IS TO THE S...FROM NEAR TAMPA BAY TO NEAR 26N93W...AND IS A STRONG MOISTURE GRADIENT. UPPER TROUGH ACROSS W GULF AND SPEED DIVERGENCE TO THE E AIDING IN MAINTAINING ACTIVE CNVTN ALONG AND TO THE S OF THIS TROUGH. BROAD TROFFING ACROSS THE SW GULF JUST TO THE S OF THE BASE OF UPPER TROUGH ALSO REMAINS ACTIVE CONVECTIVELY...BUT HAS DIMINISHED IN PAST 6 HOURS. SELY LLVL WIND SURGE CAN BE SEEN FORCING SQUALLS AND LINES OF SHOWERS AND TSTMS TO THE NW ACROSS THE SW AND W CENTRAL GULF. AMPLE TROPICAL MOISTURE BEING PULLED FROM THE EPAC MONSOON TROUGH ALONG THE MEXICAN COAST...ACROSS THE ISTHMUS AND INTO THE GULF. GFS HAS BEEN VERY AGGRESSIVE IN DEVELOPING A LOW AND POSSIBLE TROPICAL CYCLONE ACROSS THE SW GULF DURING THE NEXT 24-48 HOURS. HOWEVER THE ECMWF...AND A RECENT WINDSAT PASS SUGGEST THAT THERE WILL NOT BE SUFFICIENT TIME OR SPACE FOR A LOW TO DEVELOP BEFORE THIS BROAD TROFFING MOVES NW AND INTO MEXICO BY 48 HOURS. THERE IS STILL A SMALL CHANCE FOR THE GFS SOLUTION TO OCCUR...BUT AT THIS TIME I HAVE GONE MORE TOWARD THE ECMWF. SELY FLOW ACROSS THE NW GULF AND INTO THE S CENTRAL AND SW GULF OF OF THIS TROUGH WILL PERSIST THROUGH THE NEXT FEW DAYS AND GRADUALLY BUILD SEAS ACROSS THE W HALF OF THE BASIN TO 8 FT AND GREATER BETWEEN 48-72 HOURS. SW N ATLC... FIONA HAS LIFTED OUT TO THE N-NE LEAVING WEAK HIGH PRES RIDGE EXTENDING INTO THE AREA TO W CENTRAL CUBA. W TO SWLY FLOW ACROSS THE NW PART WILL GRADUALLY WEAKEN NEXT 24 HOURS AS EARL AND REINFORCING UPPER TROUGH SHIFT NE ACROSS NEW ENGLAND...AND LEAVE A MEANDERING FRONTAL TROUGH ACROSS THE FAR NW WATERS NEXT FEW DAYS. FADING NE SWELL ACROSS THE WATERS WILL END BY 24 HOURS LEAVING LIGHT TO MODERATE WINDS AND MODEST SEAS THROUGH THE WEEKEND...WITH MODERATE ELY TRADES BUILDING INTO THE AREA S OF 23N LATE SUN INTO MON. THE REMNANTS OF GASTON CONTINUE TO PROGRESS WWD ACROSS THE CENTRAL TROPICAL ATLC AND SHOULD PASS EITHER ACROSS THE NE CARIB OR ACROSS THE NE CARIB ISLANDS AND INTO THE AREA LATE TUE THROUGH LATE WED. THERE IS A VIGOROUS LLVL CIRCULATION WITH THIS FORMER T.S. BUT IS BEING HAUNTED BY SAL. SHOULD THIS FEATURE BEGIN TO MAINTAIN SIGNIFICANT CNVTN DURING THE NEXT FEW DAYS...MODELS FORECAST CONTINUAL INTENSIFICATION. E TO E-SE SWELL FROM THIS SYSTEM WILL PROPAGATE INTO THE SE WATERS WED-THU...AND THE PRES GRADIENT WILL INCREASE AS WILL AS IT MOVES W TO W-NW. KEEP ABREAST OF LATEST GUIDANCE ON THIS FEATURE. CARIBBEAN SEA AND TROPICAL N ATLC... SE FLOW CONTINUES AT 15-20 KT ACROSS GULF OF HONDURAS AND E AT 15-20 KT WITH ISOLATED AREAS TO 25 KT ACROSS THE CENTRAL CARIB...AND THIS SHOULD CONTINUE THROUGH MON. THE REMNANTS OF GASTON ARE EXPECTED TO ARRIVE IN THE TROPICAL N ATLC WATERS MON MORNING ALONG ABOUT 16.5N AND MOVE W TOWARDS THE LEEWARDS. WE CURRENTLY HAVE A VERY CONSERVATIVE FORECAST OF 20-25 KT ACROSS THE NRN SEMICIRCLE OF THIS LOW...WITH SEAS TO 9 OR 10 FT AS THIS LOW MOVES THROUGH THE TROPICAL WATERS. HOWEVER...ANY SUSTAINED CONVECTIVE OUTBURSTS WILL LEAD TO INTENSIFICATION...AND FORECASTS WILL HAVE TO BE RAMPED UP QUICKLY. THE REMAINDER OF THE FORECAST IS THUS VERY DEPENDENT ON STRENGTH AND TRACK OF THIS TROPICAL LOW...SO EXPECT A LOT OF TWEAKING IN EACH FORECAST PACKAGE OVER THE NEXT FEW DAYS. WARNINGS... SUBJECT TO CHANGE BASED ON POTENTIAL NHC ADVISORIES FOR GASTON REMNANTS SW N ATLC... .NONE. CARIBBEAN... .NONE. TROPICAL N ATLC... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING