000 AXNT20 KNHC 221111 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU APR 22 2010 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC... ...THE ITCZ... ITCZ AXIS IS CENTERED FROM LIBERIA NEAR 6N9W ALONG 4N20W 1N30W EQ40W AND INTO NE BRAZIL TO 2S53W. ISOLATED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-6N BETWEEN 15W-20W. SCATTERED STRONG CONVECTION IS FROM EQ-3N BETWEEN 33W-43W. ISOLATED MODERATE/STRONG CONVECTION IS FROM 1N-9N BETWEEN 43W-49W. ...DISCUSSION... THE GULF OF MEXICO... A SURFACE RIDGE CONTINUES TO IMPACT THE GULF OF MEXICO THIS MORNING ANCHORED BY A 1014 MB HIGH S OF MOBILE ALABAMA NEAR 28N87W KEEPING CONDITIONS FAIR ACROSS THE BASIN. AN UPPER LEVEL RIDGE EXTENDS ACROSS THE GREAT PLAINS AND THE WRN GULF SUPPORTING THE SURFACE RIDGE. AN UPPER LEVEL TROUGH EXTENDS TO THE E WITH AXIS ACROSS THE W ATLC. WATER VAPOR IMAGERY INDICATES DRY AIR AND SUBSIDENCE ACROSS THE ERN THIRD OF THE BASIN BETWEEN THE UPPER RIDGE AND UPPER TROUGH...WHILE UPPER LEVEL MOISTURE FLOWS FROM THE E PACIFIC ACROSS CENTRAL MEXICO TO THE WRN GULF SUPPORTING HIGH CLOUDS. EXPECT THE SURFACE RIDGE TO SHIFT EWD ALLOWING SLY RETURN FLOW TO INCREASE ACROSS THE WRN GULF TODAY AND FRI AHEAD OF A COLD FRONT FORECAST TO MOVE OFF THE TEXAS COAST LATE FRI. THE CARIBBEAN SEA... SHOWER ACTIVITY PREVIOUSLY OVER HONDURAS HAS NOW MOSTLY DIMINISHED. POSSIBLE ISOLATED SHOWERS REMAIN WITHIN 150 NM EITHER SIDE OF A SURFACE TROUGH EXTENDING DOWN THE YUCATAN PENINSULA TO HONDURAS ALONG 22N88W 17N89W 13N88W. ISOLATED SHOWERS ARE ALSO ACROSS THE NE CARIBBEAN N OF 16N BETWEEN 63W-69W IMPACTING PUERTO RICO...THE VIRGIN ISLANDS...AND ERN HISPANIOLA. TOTAL PRECIPITABLE WATER IMAGERY INDICATES ENHANCED LOW-LEVEL MOISTURE OVER MUCH OF THE ERN CARIBBEAN. THE REMAINDER OF THE AREA IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED E OF THE LESSER ANTILLES. MODERATE TRADE WINDS ARE ACROSS THE MAJORITY OF THE AREA. THE TRADES ARE FORECAST TO INCREASE AS HIGH PRESSURE OVER THE ERN GULF SHIFTS EWD AND STRENGTHENS. THE ATLANTIC OCEAN... AN UPPER LEVEL TROUGH OVER THE W ATLC EXTENDS E OF THE FLORIDA PENINSULA SUPPORTING A LOW PRESSURE SYSTEM OFF THE COAST OF N CAROLINA. A SURFACE TROUGH STRETCHES FROM THE LOW CENTER AND INTO THE DISCUSSION AREA ALONG 32N74W TO 30N78W. SCATTERED SHOWERS ARE WITHIN 75 NM AHEAD AND 30 NM BEHIND THE TROUGH AXIS. A SECOND SURFACE TROUGH HUGS THE FLORIDA PENINSULA COASTLINE FROM THE BAHAMAS ALONG 25N78W TO 29N80W. A FEW ISOLATED SHOWERS ARE POSSIBLE NEAR THE AXIS. AN UPPER LEVEL RIDGE EXTENDS FROM E OF THE LESSER ANTILLES ALONG 50W SUPPORTING A WEAK SURFACE RIDGE ANCHORED BY A 1015 MB HIGH NEAR 35N62W. HOWEVER...A FRONTAL SYSTEM DISRUPTS THE RIDGE WITH A COLD FRONT ENTERING THE DISCUSSION AREA ALONG 32N36W 24N47W TO A 1012 MB LOW NEAR 25N63W. A DISSIPATING COLD FRONT EXTENDS FROM THE LOW CENTER TO NEAR 20N66W. SCATTERED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE FRONT AXIS E OF 50W...AND FROM 23N-29N BETWEEN 50W-61W. ISOLATED SHOWERS ARE ALSO WITHIN 180 NM E OF THE DISSIPATING FRONT AXIS S OF THE LOW PRESSURE CENTER. THIS SYSTEM IS SUPPORTED BY AN UPPER LEVEL LOW E OF NEWFOUNDLAND WITH UPPER TROUGH AXIS EXTENDING SE ACROSS THE AZORES ISLANDS TO THE CANARY ISLANDS. ACROSS THE E ATLC...A SURFACE RIDGE DOMINATES ANCHORED BY A 1018 MB HIGH NEAR 24N32W PROVIDING GENERALLY FAIR WEATHER ACROSS THAT PORTION OF THE BASIN. THE SURFACE RIDGE IS SUPPORTED BY A NARROW UPPER LEVEL RIDGE ALONG 19W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON