000 AXNT20 KNHC 281137 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUL 28 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 1000 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS IN THE CENTRAL ATLC ALONG 18N37W 13N41W 7N44W MOVING W 15-20 KT. SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE BROAD CYCLONIC FLOW ABOUT THE WAVE AXIS. THE WAVE ALSO LIES EMBEDDED IN A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-9N BETWEEN 37W-42W. SIMILAR ACTIVITY IS FROM 10N-15N BETWEEN 42W-48W. TROPICAL WAVE IS ACROSS THE LESSER ANTILLES ALONG 17N61W TO 6N65W MOVING W NEAR 12 KT. UPPER AIR SOUNDINGS FROM BARBADOS INDICATE A SURGE OF MOISTURE AROUND 28/0000 UTC. THIS MOISTURE SURGE BEHIND THE WAVE AXIS IS ALSO PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE/STRONG CONVECTION IS FROM 12N-15N BETWEEN 60W-64W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N13W 9N27W 9N42W 8N53W 10N61W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OFF THE COAST OF AFRICA FROM 7N-12N BETWEEN 13W-21W. NUMEROUS STRONG CONVECTION IS FROM 8N-11N BETWEEN 22W-25W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-8N BETWEEN 32W-37W. SIMILAR ACTIVITY IS FROM 5N-11N BETWEEN 52W-58W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH PARALLELS THE SE MEXICAN COASTLINE ALONG 24N97W TO 19N95W IN THE SW GULF OF MEXICO ENHANCING NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS FROM 18N-21N BETWEEN 93W-97W. DIFFLUENCE ALOFT BETWEEN AN UPPER LEVEL LOW OVER N CENTRAL TEXAS AND AN UPPER RIDGE COVERING THE SE CONUS IS ALSO SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS OVER THE NW GULF FROM 24N-27N BETWEEN 95W-97W...AND FROM 27N-30N BETWEEN 93W-95W. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING ANCHORED BY A 1021 MB HIGH S OF MOBILE ALABAMA NEAR 28N87W MAINTAINING FAIR CONDITIONS AND MOSTLY CLEAR SKIES. ALOFT...A BROAD UPPER LEVEL LOW IS SPINNING ACROSS THE N CENTRAL GULF SUPPORTING A FEW HIGH CLOUDS. EXPECT THE SURFACE RIDGE TO GRADUALLY SHIFT WWD SUPPORTING GENERALLY FAIR WEATHER ACROSS THE BASIN. CARIBBEAN SEA... A TIGHT PRESSURE GRADIENT BETWEEN SURFACE RIDING ACROSS THE ATLC AND LOWER PRESSURES ACROSS NRN SOUTH AMERICA IS MAINTAINING STRONG TRADEWINDS ACROSS MUCH OF THE BASIN. DRY AIR ALOFT AROUND AN UPPER LEVEL TROUGH CENTERED S OF JAMAICA IS PROVIDING CLEAR SKIES OVER THE AREA. HOWEVER...DIFFLUENCE AROUND THE BASE OF THE UPPER TROUGH IN COMBINATION WITH SURFACE CONVERGENCE NEAR AN EXTENSION OF THE E PACIFIC ITCZ ACROSS COSTA RICA TO COLOMBIA IS ENHANCING SCATTERED STRONG CONVECTION S OF 12N BETWEEN 73W-80W. A TROPICAL WAVE IS MOVING ACROSS THE LESSER ANTILLES SUPPORTING ISOLATED MODERATE CONVECTION FROM 12N-15N BETWEEN 60W-64W AS WELL AS INLAND OVER VENEZUELA. ELSEWHERE ALOFT...UPPER LEVEL RIDGING COVERS THE ERN CARIBBEAN CENTERED E OF THE LESSER ANTILLES NEAR 14N58W. EXPECT MOSTLY DRY CONDITIONS ACROSS MUCH OF THE BASIN WITH SHOWERS/THUNDERSTORMS IN THE E CARIBBEAN AS THE TROPICAL WAVE PROGRESSES WWD. ATLANTIC OCEAN... SURFACE RIDGING ANCHORED BY A 1019 MB HIGH N OF THE BAHAMAS NEAR 27N75W IS MAINTAINING FAIR CONDITIONS ACROSS THE W ATLC SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OFF THE COAST OF SOUTH CAROLINA NEAR 31N77W. AN UPPER LEVEL TROUGH TO THE N OF THE UPPER RIDGE IS SUPPORTING A STATIONARY FRONT ACROSS THE NRN BORDER OF THE DISCUSSION AREA ALONG 32N61W 30N69W 32N78W. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 45 NM EITHER SIDE OF THE FRONT BETWEEN 59W-70W. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1024 MB HIGH NEAR 30N40W PROVIDING FAIR WEATHER ACROSS THE AREA. ALOFT...A NARROW UPPER LEVEL TROUGH EXTENDS FROM 31N52W TO N OF PUERTO RICO. AN UPPER LEVEL RIDGE IS CENTERED E OF THE LESSER ANTILLES NEAR 14N58W WITH A BROAD UPPER LEVEL TROUGH TO ITS E ALONG 21N43W TO 1N37W. UPPER LEVEL RIDGING COVERS THE E ATLC CENTERED BETWEEN THE CAPE VERDE ISLANDS AND THE CANARY ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON