000 AXNT20 KNHC 280552 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS IN THE CENTRAL ATLC ALONG 17N34W 12N40W 5N44W 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 6N-9N BETWEEN 38W-43W. CLUSTERS OF MODERATE/STRONG CONVECTION ARE ALSO FROM 14N-16N BETWEEN 41W-44W. TROPICAL WAVE IS ACROSS THE LESSER ANTILLES ALONG 18N58W TO 8N63W 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 ALONG THE WAVE AXIS FROM 12N-14N. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N14W 12N25W 13N38W 8N50W 7N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OFF THE COAST OF AFRICA FROM 7N-11N BETWEEN 10W-16W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 8N-11N BETWEEN 18W-25W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-9N BETWEEN 31W-36W. SIMILAR ACTIVITY IS FROM 6N-10N BETWEEN 50W-56W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH PARALLELS THE SE MEXICAN COASTLINE ALONG 24N97W TO 18N94W IN THE SW GULF OF MEXICO ENHANCING SCATTERED SHOWERS/THUNDERSTORMS FROM 22N-25N BETWEEN 95W-97W. NUMEROUS STRONG CONVECTION IS ALSO FROM 17N-20N BETWEEN 93W-96W. THESE AREAS OF CONVECTION ARE FURTHER SUPPORTED BY DIFFLUENCE ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE SW GULF AND AN UPPER LEVEL RIDGE OVER S CENTRAL MEXICO. AN UPPER LEVEL LOW OVER N CENTRAL TEXAS IS ALSO SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS OVER THE NW GULF INDICATED BY RADAR DATA. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING ANCHORED BY A 1020 MB HIGH S OF MOBILE ALABAMA NEAR 28N89W MAINTAINING FAIR CONDITIONS AND CLEAR SKIES. ALOFT...ANOTHER 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-83W. A TROPICAL WAVE IS MOVING ACROSS THE LESSER ANTILLES SUPPORTING ISOLATED MODERATE CONVECTION FROM 12N-15N BETWEEN 60W-62W AS WELL AS INLAND OVER VENEZUELA. ELSEWHERE ALOFT...UPPER LEVEL RIDGING COVERS THE ERN CARIBBEAN CENTERED E OF THE LESSER ANTILLES NEAR 14N57W. 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 1020 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 31N75W. AN UPPER LEVEL TROUGH TO THE N OF THE UPPER RIDGE IS SUPPORTING A COLD FRONT PUSHING INTO THE DISCUSSION AREA ALONG 32N60W 30N69W 32N78W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1025 MB HIGH NEAR 30N39W 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 14N57W WITH A BROAD UPPER LEVEL TROUGH TO ITS E ALONG 19N47W TO EQ33W. 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