000 AGXX40 KNHC 050549 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 200 AM EDT SUN SEP 05 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... QUASI STATIONARY FRONTAL TROUGH EXTENDS FROM FL PANHANDLE TO JUST E OF EXTREME SE TX ATTM. WINDS NW OF TROUGH ARE AT 15 KT AS EXPECTED. REMNANTS OF THIS TROUGH SHOULD WASH OUT COMPLETELY BY MON AFTERNOON. BROAD AND PERSISTENT TROUGH OVER THE SW GULF HAS A SMALL SURFACE LOW ON THE COAST AT 19N95W. THIS WEAK LOW SHOULD TRACK NW HUGGING THE COAST UNTIL MOVING WELL INLAND NEAR 24N98W LATE NIGHT. A TROUGH EXTENDS N FROM THE LOW ALONG 94W AT THE MOMENT...AND IS EXPECTED TO MOVE W IN PHASE WITH THE LOW WITH PRES GRADIENT INCREASING E OF THE TROUGH AXIS. GFS STILL MOST AGGRESSIVE AND SUGGESTING NEARLY TWICE THE WIND STRENGTH OF OTHER GUIDANCE. EVEN IF CURRENT SURFACE LOW MAINTAINS ITSELF...ITS SW SEMICIRCLE IS EXPECTED TO HUG COAST DURING ITS NW TRACK LIMITING DEVELOPMENT...HOWEVER NHC SUGGESTS THE CONTINUED POSSIBILITY OF DEVELOPMENT...SO PSBL TRPCL CYCLONE DEPICTED ON GRAPHICS. E TO SE WINDS CURRENTLY AT 15 KT E OF TROUGH AXIS SHOULD INCREASE TO 15 TO 20 KT...WITH A SMALL SWATH OF SE 25 KT...TONIGHT OVER SW BAY OF CAMPECHE. BY TUE E-SE FLOW ACROSS ENTIRE GULF AT 10-15 KT N HALF AND 15-20 KT S HALF DIMINISHING SOME ON WED AND THU. SW N ATLC... HIGH PRES CENTERED NEAR 27N67W RIDGES W-SW TO FL STRAITS. A FRONTAL TROUGH IS ALONG THE GA COAST AND IS EXPECTED TO STALL AND MEANDER OVER THE EXTREME NW WATERS THROUGH MON BEFORE DISSIPATING. E WINDS THROUGHOUT THE AREA TUE...THEN FORECAST UNCERTAINTY INCREASES AS REMNANTS PASS TO THE S. TROPICAL CYCLONE GUIDANCE SUGGESTS W TRACK ALONG ABOUT 17N-18N AND DEVELOPING TO HURRICANE STRENGTH. CONVECTION IS NOT PERSISTENT... THUS SYSTEM HAS NOT BEEN UPGRADED. IN ANY EVENT...EXPECT A TROPICAL LOW TO TRACK W THROUGH THE NE CARIBBEAN WITH E TRADES INCREASING...AND PERHAPS BACKING SLIGHTLY TO THE NE...AS EARLY AS TUE NIGHT OVER THE PUERTO RICO TRENCH. E-SE SWELLS SHOULD ALSO ARRIVE BUILDING SEAS TO 5-8 FT OVER AREA S OF 23N E OF THE BAHAMAS WED AND THU. CARIBBEAN SEA AND TROPICAL N ATLC... SE FLOW IS AT 15-20 KT ACROSS THE GULF OF HONDURAS AND E AT 15-20 KT ALONG N COAST OF COLOMBIA. EXPECT LITTLE CHANGE THROUGH SUN...THEN PRES GRADIENT WILL RELAX SOME OVER THE S CENTRAL WATERS AND SPREADING W TO THE GULF OF HONDURAS ON WED NIGHT INTO THU. PLENTY OF UNCERTAINTY THIS UPCOMING WEEK AS REMNANTS OF GASTON ARE EXPECTED TO REGENERATE AND TRACK W ACROSS THE NE CARIBBEAN ALONG 17N-18N. ALTHOUGH CYCLONE GUIDANCE SUGGESTS EVENTUAL HURRICANE STRENGTH...CURRENT CONVECTION DOES NOT PERSIST LONG ENOUGH FOR UPGRADING. SO WILL MOVE TROPICAL LOW W ACCOMPANIED BY CYCLONIC WINDS OF 20-30 KT AND SEAS 8-13 FT. PRESSURE GRADIENT...AND THUS WIND AND SEAS FORECASTS...OVER REMAINDER OF AREA 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 TILL WE GET A BETTER HANDLE ON REMNANTS OF GASTON. WARNINGS... SUBJECT TO CHANGE BASED ON LATEST NHC ADVISORY 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 NELSON