000 AGXX40 KNHC 210638 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 AM EDT THU APR 21 2011 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... SURFACE DATA AND AN EARLIER ASCAT PASS SHOWED NUMEROUS WIND BARBS OF 20 KT OVER THE CENTRAL AND WESTERN PORTIONS OF THE GULF. HIGH PRES REMAINS IN CONTROL OF THE WEATHER PATTERN ACROSS THE REGION. THE PRESSURE GRADIENT BETWEEN THIS HIGH CURRENTLY CENTERED OVER THE NE PART OF THE GULF AND TROUGHING OVER THE PLAINS AND NE MEXICO WILL RESULT IN MODERATE TO FRESH SE RETURN FLOW OVER THE GULF THROUGH THE FORECAST PERIOD. EXPECT WINDS OF 20 KT ACROSS MOST OF THE GULF REGION OVER THE WEEKEND AS HIGH PRES STRENGTHENS ALONG THE EASTERN CONUS AND THE WESTERN ATLC. COMPUTER GUIDANCE INDICATES A 1035 MB HIGH PRES SE OF NOVA SCOTIA WITH A RIDGE EXTENDING SW INTO THE GULF REGION. SOUTHWEST N ATLC... LOW PRES E OF THE AREA COMBINED WITH A RIDGE ACROSS THE N PORTION OF THE SW N ATLC IS PRODUCING 20-25 KT NE WINDS OVER THE EASTERN PORTION OF THE ZONE. BUOYS 41046 AND 41047 ALONG WITH THE 0220 ASCAT PASS VERIFIED THESE WIND SPEEDS. THE LOW IS CURRENTLY PRODUCING GALE FORCE WINDS WITHIN 150 NM NE QUADRANT BUT IS FORECAST TO WEAKEN TO BELOW GALE FORCE THU AFTERNOON. THIS SYSTEM CURRENTLY LOCATED NEAR 23N62W WILL MOVE TO 26N63W THU EVENING THEN WILL MEANDER THERE THROUGH FRI EVENING. AT THE SAME TIME...HIGH PRES WILL BUILD ACROSS THE EASTERN CONUS AND THE WESTERN ATLC RESULTING IN A TIGHTENING PRES GRADIENT BETWEEN THE HIGH AND THE LOW PRES THAT WILL REMAIN E OF THE AREA BUT CLOSE. EXPECT WINDS OF 20-25 KT ACROSS THE EASTERN PART OF THE AREA THROUGH SUN WHILE SPREADING E OF THE BAHAMAS. AS HIGH PRES CONTINUES TO INTENSIFY ACROSS THE REGION...THE LOW PRES IS FORCED TO MOVE SOUTH AND WEAKEN BY SAT ENTERING THE TROPICAL N ATLC LATE SAT. THE LOW IS FORECAST BY THE COMPUTER MODELS TO OPEN UP INTO A TROUGH NEAR OR OVER PUERTO RICO BY SUN. CARIBBEAN SEA AND TROPICAL ATLC W OF 55W... RATHER TRANQUIL CONDITIONS PREVAIL ACROSS THE CARIBBEAN SEA WITH THE ONLY EXCEPTIONS BEING THE GULF OF HONDURAS AND THE WINDWARD PASSAGE WHERE WINDS OF 20 KT ARE BLOWING. THESE CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE GULF OF HONDURAS THROUGH FRI NIGHT THEN DECREASE TO BELOW 20 KT OVER THE WEEKEND INTO EARLY NEXT WEEK. WINDS THROUGH THE WINDWARD PASSAGE WILL CONTINUE THROUGH THE WEEKEND THEN DECREASE TO LESS THEN 20 KT ON MON. OTHERWISE ELY WINDS OF 10-15 KT ACROSS THE REMAINDER OF THE CARIBBEAN WITH SEAS BELOW 6 FT. SEAS WILL SLIGHTLY INCREASE TO 7 FT NEAR THE COAST OF COLOMBIA LATE FRI. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER GR