000 AGXX40 KNHC 181906 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 305 PM EDT MON OCT 18 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... VERY WEAK PRES PATTERN ACROSS THE GULF TODAY WITH TWO POSSIBLE WEAK HIGH CENTERS ACROSS THE N GULF...ONE NW...ONE NE. A COASTAL TROUGH APPEARED EVIDENT IN VIS STLT IMAGERY THIS MORNING JUST OFFSHORE OF THE W COAST OF THE BAY OF CAMPECHE...WHILE A BROAD CYCLONIC CURL WAS NOTED OFF THE N COAST OF THE YUCATAN. MILD WINDS THUS PREVAILED ACROSS THE BASIN...WITH HIGHEST WINDS AND SEAS LIKELY ACROSS THE SE GULF IN NELY FLOW 10-15 KT AND SEAS AROUND 3 FT. WEAK TROFFING IS EXPECTED TO DEVELOP ACROSS THE SE GULF NEXT 24-48 HOURS...POSSIBLY ASSOCIATED WITH CYCLONIC CURL N OF YUCATAN...AND WILL INDUCE A NELY FLOW TO THE NW ACROSS THE E CENTRAL GULF SRN STREAM S/W TROUGH MOVING INTO W GULF WILL MOVE OVER CARIB UPPER RIDGE AND WEAKEN THROUGH MID WEEK...WITH N PORTION EVENTUALLY COMING INTO PHASE WITH LONG WAVE TROUGH ACROSS THE NE U.S. THIS WILL DRAG A SERIES OF COLD FRONTS ALONG THE GULF COAST STATES THIS WEEK. COOL AIR BEHIND THESE WEAK AND DISSIPATING BOUNDARIES WILL SPILL INTO THE NE GULF TO FORM A QUASI STATIONARY BOUNDARY NE TO SW FROM CENTRAL FLORIDA TO CENTRAL GULF. BOTTOM LINE...CONTINUED TRANQUIL CONDITIONS ACROSS THE BASIN WITH PEAK WINDS AND SEAS LIKELY TO OCCUR S OF 25N BETWEEN 85W AND 90W IN NELY FLOW TO NEAR 15 KT...WITH SEAS 3-4 FT POSSIBLY AS HIGH AS 5 FT. CARIBBEAN... SHEAR LINE EXTENDING NEARLY E TO W ALONG 22N AND INTO SE BAHAMAS TO N COAST OF CUBA...WITH LLVL REFLECTION OF CUT OFF MID TO UPPER LEVEL LOW MOVING SLOWLY W ACROSS THE LEEWARDS AND INTO NE CARIB ATTM...AND MAKING FOR MILD NE TO E TRADES. SUBSIDENCE AND FAIR WEATHER GENERALLY E OF 69W ACROSS THE CARIB AND ADJACENT TROPICAL N ATLC. FOCUS CONTINUES TO BE CYCLONIC GYRE ACROSS W CARIB AND FAR TROPICAL EPAC...S OF 19N AND BETWEEN 75W AND 92W. MID LEVEL VORT OFF COASTS OF HONDURAS AND NICARAGUA CONTINUES TO AID IN FORCING BANDS OF DEEP CNVTN ACROSS THE W AND NW CARIB. ANY DEVELOPMENT OF THIS TYPE OF SYSTEM IS SLOW TO OCCUR AS IS SEEN IN THE W PACIFIC. GLOBAL MODELS CONTINUE TO SHOW ONLY MODEST ORGANIZATION OF ANY LLVL LOW ACROSS THIS REGION...WITH MODEL CONSENSUS SHOWING LOWS LIFTING N FROM OFFSHORE OF NICARAGUA AND THEN MOVING SSE INTO SW CARIB...OR REDEVELOPING TO THE S AND SW...WITH POTENTIAL LATER IN THE PERIOD FOR CYCLOGENESIS IN THE EPAC. WEATHER IN THE FORM OF SQUALLS AND TSTMS WILL REMAIN ACTIVE FOR THE NEXT FEW DAYS ACROSS THIS AREA AS THE CNVTN MAINTAINS UPPER RIDGING...BUT SIGNIFICANT DEVELOPMENT OF THIS SYSTEM WILL BE SLOW...AND AT PRESENT IS NOT ANTICIPATED IN THE NEXT 48 HOURS...WHICH IS REFLECTED IN THE 30 PERCENT PROBABILITY FOR TROPICAL CYCLOGENESIS BY NHC. LOOK FOR 15-20 KT WINDS TO OCCUR AROUND THE PERIPHERY OF THE LOW...WITH SEAS 4-6 FT...AND HIGHER IN SQUALLS AND TSTMS. ATLC... RECENT OBS AND SCATTEROMETER PASSES SHOW NE TO E WINDS OF 20-25 KT WITHIN 180 NM N OF THE SHEAR LINE...WITH SEAS 6-8 FT IN MIXED NE WIND WAVES AND N-NW SWELL. THE SHEAR LINE WILL GRADUALLY WEAKEN NEXT 48 HOURS AND BEGIN TO DRIFT N AS AN INVERTED TROUGH DEVELOPS FROM THE CENTRAL BAHAMAS NNE TO NEAR 30N74W...OUT AHEAD OF ONE OF THE FRONTAL BOUNDARIES THAT WILL SWEEP ACROSS THE GULF COAST STATES AND SE U.S. NEXT FEW DAYS. MODEL SHOW VARIOUS STRENGTH OF THIS TROUGH...BUT CONSENSUS IS FOR ATLC HIGH TO OPEN UP AHEAD OF THIS TROUGH AS IT IS NUDGED EWD BY ERN U.S. L/W TROUGH THU-FRI...WITH SLY FLOW TO 20 KT LIKELY TO DEVELOP OUT AHEAD OF SURFACE TROUGH...JUST ON THE E EDGE OF LOCAL AREA. WEAK BOUNDARIES WILL DROP INTO NW PORTIONS WITH WEAK RIDGING FROM THE GULF E ACROSS FLORIDA...AND MAINTAIN GENERALLY LIGHT TO MODERATE WINDS. WINDS AND SEAS ALONG AND N OF CURRENT SHEAR LINE WILL BEGIN TO DIMINISH TUE AND THE SHEAR LINE BEGINS TO DRIFT N AND GRADIENT WEAKENS. N-NW SWELL CURRENTLY MOVING ACROSS E PORTIONS AND INTO SE PORTIONS WILL PEAK THIS EVENING AND TONIGHT AND MOVE THROUGH THE ATLC PASSAGES AND INTO THE CARIB...WITH SEAS IN THE PASSAGES EXPECTED AROUND 6 FT. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING