000 AGXX40 KNHC 130452 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT THU APR 13 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. PERSISTENT UPPER TROUGH WITH A VORTICITY CENTER OVER CENTRAL CUBA TONIGHT STATIONARY PAST FEW HOURS. STRONG UPPER RIDGE CENTERED OVER NRN MEXICO DIVERTING NRN BRANCH ESE OFF MID ATLC COAST. ON THE SURFACE A STATIONARY FRONT EXTENDS FROM 31N58W SW TO A WEAK 1009 MB LOW OVER THE SE BAHAMAS. A LARGE RIDGE EXTENDS SW OVER THE SW ATLC INTO THE NRN GULF. THE CUTOFF LOW OVER ERN CUBA APPEARS TO WEAKEN DAY 1 AS LITTLE IN THE WAY OF ADDITIONAL COLD AIR MOVES SE. ONE SHORTWAVE MOVES TO MID OCEAN ALONG 55W BUT JUST N OF THE AREA. A LARGE CYCLONIC CIRCULATION CONTINUES OVER THE ERN ATLC E OF 35W. A LARGE UPPER RIDGE REMAINS OVER MEXICO. GUSTY NE WINDS TO 25 KT WILL CONTINUE OVER THE ATLC W OF 60W WHERE THE PRESSURE GRADIENT REMAINS FAIRLY STRONG. SE GULF AND NW CARIB WINDS TO 20 KT OTHERWISE REMAINDER OF THE AREA MOSTLY LIGHT WINDS DAY 1. THE WESTERLIES MANAGE TO ERODE THE UPPER RIDGE JUST ENOUGH TO SWEEP THE UPPER TROUGH THAT HAS BEEN OVER CUBA THE PAST FEW DAYS EWD. THE STRONG WLY FLOW ACROSS THE ATLC N OF 20N SHOVES THE E ATLC TROUGH EWD. ON THE SURFACE THE GRADIENT WEAKENS DAY 2 OVER THE SW ATLC N OF 28N AS THE STATIONARY FRONT MOVES EWD. THE RIDGE RE-ESTABLISHES ITSELF OVER THE N GULF WITH MOSTLY LIGHT WINDS. STILL SOME GUSTY NE WINDS OVER THE NW CARIB DAY 2 OTHERWISE THE CARIB SHOULD HAVE MOSTLY LIGHT WINDS. OUTLOOK PERIOD... STRONG ENTRUSION OF WESTERLIES E OF 80W AS THE UPPER FLOW TOPS THE UPPER RIDGE OVER THE CENTRAL US DAY 3. SOME WEAK TROUGHING OVER THE SW ATLC STILL EVIDENT BUT VORTICITY FIELD WEAK. GFS MODEL WANTS TO CRANK UP SURFACE LOW TO 1008 MB OVER MID OCEAN NEAR 25N55W WHICH MAY BE A LITTLE OVER DONE GIVEN THE UPPER PATTERN. OTHERWISE WEAK PRESSURE GRADIENT OVER REMAINDER OF REGION. SOME RETURN FLOW W OF 90W SETS UP DAY 3. STRONG WESTERLIES BECOME MORE ZONAL DAY 4 WITH WHATS LEFT OF SW ATLC UPPER TROUGH MOVING EWD TO 60W. SURFACE LOW 1009 MB OVER MID OCEAN MOVES NE TO NEAR 29N47W WITH WINDS TO 25 KT. WEAK RIDGE ALONG 24N W OF 60W DAY 4 WITH WLY WINDS 20 KT N OF 28N AND RETURN FLOW W OF 90W TO 20 KT. A LARGE CLOSED OFF UPPER CYCLONIC CIRCULATION WELL N OF THE AREA OFF THE NEW ENGLAND COAST BEGINS TO LOWER MID LEVEL HEIGHTS OVER THE SW ATLC. AN UPPER RIDGE BUILDS ALONG 90W OTHERWISE THE UPPER FLOW REMAINS ZONAL. WEAK SURFACE LOW 1010 MB MOVES TO 31N42W WITH A TRAILING FRONT TO 20N51W. WEAK RIDGING REMAINS ALONG 23N WITH GUSTY SW WINDS N OF 28N W OF 60W. RETURN FLOW W OF 90W TO 20 KT OTHERWISE REMAINDER OF AREA MOSTLY LIGHT WINDS. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG