000 AGXX40 KNHC 191857 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 258 PM EDT MON APR 19 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... SFC LOW HAS SHIFTED E-NE AND OPENED UP JUST E OF THE NW BAHAMAS WITH ELONGATED TROFFING EXTENDING W-SW THROUGH THE STRAITS OF FLORIDA TO THE FAR SE GULF ALONG 84W. NLY FLOW AROUND 15 KT PREVAILS ACROSS W TAIL OF THIS TROUGH OVER FAR SE GULF WHERE SEAS WERE 4-5 FT THIS MORNING. ELSEWHERE STALLED AND WEAKENING FRONTAL BOUNDARY MEANDERED ALONG N GULF COASTS TO A 1012 MB LOW NEAR 28N94.5W WITH WEAK COLD FRONTAL TROUGH EXTENDING S-SW TO CYCLONIC CONVERGENCE ZONE INVOF 22N95.5W. ISOLATED STRONG CNVTN CONTINUES ATTM ACROSS THE NE GULF...WHERE MID/UPPER LEVEL S/W WAS LIFTING E-NE OUT OF THE NE GULF...AND ALSO ALONG THE FRONTAL TROUGH IN THE W GULF...WHERE A NWLY JET SEGMENT WAS PASSING OVERHEAD. PROGRESSIVE PATTERN WILL CONTINUE THIS WEEK AND ALLOW FOR FRONTAL SYSTEM ACROSS N AND W GULF TO SHIFT E-NE NEXT 24-48 HOURS AND SHIFT SLOWLY E AND NE OUT OF THE BASIN NEXT 48 HOURS WITH WEAK HIGH PRES MOVING INTO THE NW THEN N CENTRAL GULF BY 48 HOURS. WINDS AND SEAS THUS BE GENERALLY REMAIN LIGHT TO MODERATE THROUGH THE PERIOD. SW N ATLC AND TROPICAL ATLC W OF 55W... S/W TROUGH ACROSS NE GULF MOVING THROUGH L/W TROUGH THAT EXTENDS FROM ERN GULF SW INTO TROPICAL EPAC. WITH UPPER RIDGE CENTERED ALONG 55W E OF LESSER ANTILLES...THIS PATTERN PRODUCING SWLY FLOW ALOFT ACROSS THE SW N ATLC W OF 70W BECOMING SW TO W FROM 70W TO 60W. WEAK ATLC COLD FRONT EXTENDS FROM 31N66W TO N FLORIDA...WHILE SFC LOW THAT MOVED ACROSS S FL YDA EVENING APPEARS TO HAVE FILLED ACROSS THE NW BAHAMAS AND A SECOND LOW HAS DEVELOPED NEAR 27N68.5W...MOVING E-NE 20 KT. BROAD AND ELONGATED TROUGHING STRETCHES FROM THIS NEWEST LOW W-SW THROUGH THE STRAITS OF FLORIDA...WITH A WARM FRONT EXTENDING FROM THIS NEW LOW AND MERGING N OF THE AREA WITH ABOVE COLD FRONT. AMPLE MOISTURE AND GOOD LLVL CONVERGENCE OCCURRING ALONG N SIDE OF THIS BROAD ELONGATED TROUGH AND ACROSS E AND SE SEMICIRCLES OF NEW LOW...YIELDING 20-25 KT WINDS AND ACTIVE CNVTN. NE WINDS 20-25 KT ALSO FOUND N OF WEAK COLD FRONT ACROSS N PORTIONS...WITH SEAS THERE TO 9 FT. THE WEAK TROUGH ACROSS N PORTIONS WILL SINK SLOWLY S NEXT 36-48 HOURS. THIS FRONT WILL BEGIN TO MERGE ACROSS NE PORTIONS TONIGHT WITH THE ELONGATED TROFFING AS IT GRADUALLY LIFTS OUT TO THE NE...WHILE THE W PORTION OF THE FRONT W OF 70 SINKS TO ALONG 25-26N NEXT 48 HOURS...AND WILL NOT LIKELY MERGE BUT COME WITHIN A FEW DEGREES OF THE TRAILING TROFFING LEFT OFF THE CENTRAL BAHAMAS. THIS WILL CAUSE THE GRADIENT TO INCREASE N OF THE MERGING BOUNDARIES E OF 70W WITH N TO NWLY WINDS INCREASING 20-25 KT AND SEAS BUILDING TO NEAR 9 FT. S TO SW FLOW LESS THAN 20 KT WILL PREVAIL S OF THE BOUNDARY...EXCEPT 20-25 KT ACROSS ERN SEMICIRCLE OF NEW LOW...WHICH WILL BE MOVING OUT OF THE AREA TONIGHT. CARIBBEAN... WEAK TROUGH OVER THE NW CARIBBEAN ASSOCIATED WITH THE ELONGATED TROFFING ACROSS THE SW N ATLC WILL EXTEND FROM CENTRAL CUBA TO NEAR THE HONDURAS-NICARAGUA BORDER THIS EVENING THEN WEAKEN AND LIFT OUT TO THE NE TUE. NW TO WINDS 10-15 KT NW OF THE TROUGH WILL BECOME N TO NE OVERNIGHT AND THEN NE TO E TUE MORNING... THEN ELY TUE AS WEAK HIGH PRES MOVES TO NEAR THE NW GULF COAST. SE TO E TRADES 15-20 KT ACROSS THE E CARIB WILL DECREASE TO 10 TO 15 KT NEXT 24 HOURS...WITH LIGHT TO MODERATE WINDS AND SEAS THEN PREVAILING THROUGH 72 HOURS...THEN INCREASE TO 15-20 KT OVER THE S CENTRAL CARIBBEAN THU AND FRI. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING