000 AXNT20 KNHC 070157 CCA TWDAT TROPICAL WEATHER DISCUSSION...CORRECTED NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI MAY 06 2011 ...CORRECTED FOR ISSUANCE TIME... TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2230 UTC. ...ITCZ... ITCZ AXIS EXTENDS FROM MAURITANIA NEAR 11N12W ALONG 5N20W 1N30W CROSSING THE EQUATOR NEAR 35W AND CONTINUING INTO NE BRAZIL NEAR 1S54W. ISOLATED MODERATE/STRONG CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN 16W-26W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 N M N...AND 160 NM S OF THE AXIS W OF 26W. ...DISCUSSION... GULF OF MEXICO... WHILE MOSTLY ZONAL WLY FLOW ALOFT COVERS THE GULF OF MEXICO...WATER VAPOR IMAGERY CONTINUES TO INDICATE A MID-UPPER LEVEL SHORTWAVE TROUGH THAT IS NOW MOVING OVER NE FLORIDA AND INTO THE FAR W ATLC. THE SHORTWAVE SUPPORTS A FORMING COLD FRONT LOCATED FROM NEAR JACKSONVILLE FL TO TAMPA CONTINUING INTO THE CENTRAL GULF NEAR 25N90W WHERE IT CONTINUES AS A SURFACE TROUGH TO THE BAY OF CAMPECHE ALONG 23N92W 19N91W...AS OF 2100 UTC. POSSIBLE ISOLATED SHOWERS ARE ALONG THE BOUNDARY OVER LAND AND WITHIN 45 NM EITHER SIDE OF THE BOUNDARY OVER WATER. A SECOND SURFACE TROUGH IS AHEAD OF THE FRONT EXTENDING ACROSS THE FLORIDA PENINSULA OVER LAKE OCKEECHOBEE FROM 27N80W TO 26N84W. A LINE OF STRONG SHOWERS IS S OF THIS BOUNDARY WITHIN 50 NM. SURFACE RIDGING IS BUILDING IN BEHIND THE FRONTAL BOUNDARY AROUND A 1018 MB HIGH CENTERED S OF CENTRAL LOUISIANA NEAR 29N92W. THE SURFACE RIDGE COMBINED WITH DRY AIR ALOFT IS PROVIDING FAIR WEATHER ACROSS THE NRN GULF. THE FRONTAL SYSTEM IS EXPECTED TO MOVE OUT OF THE AREA BY SATURDAY AFTERNOON AS SURFACE RIDGING BUILDS IN ITS WAKE. CARIBBEAN SEA... MUCH OF THE NW CARIBBEAN IS UNDER THE INFLUENCE OF AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 18N81W ALONG WITH DRY AIR AND SUBSIDENCE SUPPORTING FAIR SURFACE CONDITIONS. HOWEVER...A STRIP OF ENHANCED MOISTURE LIES OVER THE SRN CARIBBEAN SUPPORTING AREAS OF SHOWER ACTIVITY. SCATTERED SHOWERS ARE NOTED ACROSS SRN HISPANIOLA TO JAMAICA. STRONGER SHOWERS/POSSIBLE THUNDERSTORMS ARE ACROSS PANAMA...COSTA RICA...AND THE COASTAL WATERS S OF 12N BETWEEN 79W-86W. ACROSS THE ERN CARIBBEAN...A SECOND UPPER LEVEL RIDGE SITS OVER THE AREA EXTENDING FROM AN UPPER LEVEL ANTICYCLONE N OF BRAZIL NEAR 6N42W. AT THE SURFACE...A SHEAR AXIS EXTENDS FROM THE ATLC ACROSS THE WINDWARD ISLANDS ALONG 15N61W TO 12N67W SUPPORTING SCATTERED SHOWERS WITHIN 100 NM EITHER SIDE OF THE AXIS. MOISTURE LEVELS ARE EXPECTED TO REMAIN HIGH ACROSS THE SRN CARIBBEAN OVER THE NEXT COUPLE OF DAYS INCREASING THE CHANCE OF SHOWER ACTIVITY. ATLANTIC OCEAN... POSSIBLE ISOLATED SHOWERS ARE WITHIN 100 NM OFF THE NE FLORIDA COASTLINE AHEAD OF A FORMING FRONTAL BOUNDARY MOVING ACROSS THE PENINSULA. AN UPPER LEVEL SHORTWAVE TROUGH SUPPORTS THE FRONT AND IS BEGINNING TO MOVE OVER THE W ATLC. A BROAD UPPER LEVEL RIDGE IS TO THE E BETWEEN 55W-75W SUPPORTING A 1023 MB HIGH NEAR 34N71W. AN OCCLUDED LOW PRESSURE SYSTEM IS IMPACTING THE CENTRAL ATLC WITH AN UPPER LEVEL LOW CENTERED NEAR 33N48W AND THE LOW LEVEL CENTER NEAR 33N50W. A SERIES OF PERTURBATIONS ARE ASSOCIATED WITH THE SYSTEM. THE OUTERMOST SURFACE TROUGH IS ALONG 30N41W 24N44W 17N50W CONTINUING AS A SHEAR LINE TO THE WINDWARD ISLANDS NEAR 15N61W. A SECOND SURFACE TROUGH EXTENDS ALONG 30N48W 25N50W 22N56W. A LARGE AREA OF SCATTERED SHOWERS IS E OF THE OUTERMOST TROUGH N OF 21N BETWEEN 33W-42W. SCATTERED SHOWERS ARE ALSO WITHIN 150 NM E OF THE INNER TROUGH. AN UPPER LEVEL RIDGE COVER THE ERN ATLC BETWEEN 22W-38W SUPPORTING A 1021 MB HIGH NEAR 27N31W. A NARROW UPPER LEVEL TROUGH EXTENDS DOWN 11W SUPPORTING A WEAK FRONTAL SYSTEM JUST W OF THE CANARY ISLANDS ALONG 32N14W 28N23W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON