000 AXNT20 KNHC 261756 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU JUL 26 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS TILTED ALONG 16N28W 8N31W MOVING W 10-15 KT. THIS WAVE SHOWS UP WELL IN VISIBLE IMAGERY WITH LOW TO MID LEVEL CYCLONIC TURNING NOTED FROM 9N-16N BETWEEN 26W-33W. ALTHOUGH CONVECTION IS MINIMAL AND DISORGANIZED OVERALL...A RECENT FLARE UP OF SCATTERED MODERATE/ISOLATED STRONG IS FROM 12N-15N BETWEEN 29W-33W. TROPICAL WAVE IS TILTED ALONG 15N42W 11N44W 6N45W MOVING W 10-15 KT. THE WAVE IS CHARACTERIZED BY AN ELONGATED ZONE OF LOW LEVEL CYCLONIC TURNING FROM 9N-15N BETWEEN 39W-46W. LIKE ITS COUNTERPART FURTHER E...THE WAVE SHOWS UP WELL IN SATELLITE DERIVED VORTICITY AND TPW PRODUCTS. THE NEARBY MODERATE CONVECTION IS MOSTLY EMBEDDED IN THE ITCZ FROM 10N-12N BETWEEN 45W-51W. ANOTHER LESS IMPRESSIVE CLUSTER IS WITHIN 90 NM EITHER SIDE OF THE AXIS FROM 6N-8N. ALL OF THIS CONVECTION IS BEING STRETCHED TO THE W WITH UPPER ELY FLOW OVER THE AREA. A CENTRAL CARIBBEAN SEA TROPICAL WAVE IS ALONG 72W S OF 17N MOVING W NEAR 25 KT. THE WAVE PASSAGE WAS EVIDENT IN THE CURACAO SOUNDING DATA BETWEEN 26/0000 UTC AND 26/1200 UTC. ASSOCIATED SCATTERED MODERATE CONVECTION IS FROM 15N-17N BETWEEN 69W-73W. TROPICAL WAVE ALONG 96/97W S OF 21N IS NOW BECOMING MORE OF AN EPAC FEATURE. HOWEVER...SOME OF THE ASSOCIATED MID LEVEL ENERGY MAY HAVE ROUNDED THE ATLC RIDGE AND ENHANCED THE CONVECTION IN THE NW GULF. SEE GULF DISCUSSION BELOW AND THE PACIFIC TROPICAL WEATHER DISCUSSION UNDER AWIPS HEADER MIATWDEP FOR MORE INFO. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N13W 9N22W 12N26W 11N33W 12N40W 10N50W 9N61W. ASIDE FROM THE CONVECTION ALREADY MENTIONED WITH THE TROPICAL WAVES...SCATTERED MODERATE IS WITHIN 120NM S OF THE AXIS E OF 23W. A FEW STRONGER CELLS ARE WITHIN 30NM EITHER SIDE OF THE COAST OF AFRICA FROM 6N-13N. ...DISCUSSION... GULF OF MEXICO... ANOTHER ROUND OF STRONG CONVECTION IS AFFECTING THE NW GULF THIS AFTERNOON. LIGHTNING DATA...RADAR...AND SATELLITE IMAGERY DEPICT NUMEROUS SHOWERS AND TSTMS N OF 22N BETWEEN 86W-97W. THIS ACTIVITY IS LARGELY BEING SUPPORTED BY A DIFFLUENT PATTERN ALOFT BETWEEN THE UPPER LOW OVER S CENTRAL TX AND AN UPPER HIGH OVER THE NRN YUCATAN PENINSULA. THIS MORNINGS QUIKSCAT PASS DID REVEAL SOME WEAK SFC TROUGHING AS WELL. IN ADDITION...THE RECENT SERIES OF TROPICAL WAVES HAVE INCREASED THE LOW LEVEL MOISTURE IN THE VICINITY. REGARDLESS...SURFACE PRESSURES ARE NOT FALLING AND UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR SIGNIFICANT DEVELOPMENT. ELSEWHERE...A WEAK SFC HIGH IS OVER NRN FLORIDA WHICH IS EXPECTED TO DRIFT W OVER THE NEXT COUPLE OF DAYS. THIS WILL ALLOW LIGHT WINDS OVER THE NE PORTION WITH SLIGHTLY STRONGER 10-20 KT E TO SE FLOW ELSEWHERE. CARIBBEAN SEA... ASIDE FOR THE WEATHER ASSOCIATED WITH THE TROPICAL WAVE IN THE CENTRAL CARIB THE ONLY OTHER DEEP CONVECTION NOTED IS IN THE SW PORTION. THIS SCATTERED MODERATE IS S OF 12N ALONG THE COAST OF CENTRAL AMERICA...AND IS LIKELY TIED TO THE ITCZ IN ADDITION TO LOW LEVEL SPEED CONFLUENCE DOWNSTREAM FROM THE FRESH TRADES OCCURRING N OF THE COLOMBIAN COAST. MODERATE TO FRESH TRADES TO PERSIST INTO THE WEEKEND...REMAINING STRONGEST BETWEEN COLOMBIA AND HISPANIOLA. UPPER RIDGING DOMINATES THE NW AND ERN PORTIONS OF THE BASIN WHILE AN INVERTED UPPER TROUGH DOMINATES THE CENTRAL PORTION. DIFFLUENCE E OF THE UPPER TROUGH IS ENHANCING THE CONVECTION NEAR THE TROPICAL WAVE ALONG 72W. ATLANTIC OCEAN... A SFC TROUGH WAS ADDED TO THE 1500 UTC MAP IN THE WRN ATLC ALONG 30N72W 24N75W...SPARKED BY LOW LEVEL CONFLUENCE BETWEEN A NEWLY FORMED 1021 MB SFC HIGH OVER N FLORIDA AND THE FLOW AROUND THE 1026 MB HIGH IN THE CENTRAL ATLC NEAR 34N41W. ASSOCIATED SCATTERED MODERATE CONVECTION IS FROM 25N-30N BETWEEN 70W-74W. ISOLATED TSTMS ARE ALSO OVER THE NW BAHAMAS AND ADJACENT WATERS AGAIN THIS AFTN. A WELL DEFINED UPPER LOW NEAR 32N56W HAS ISOLATED TSTMS N OF 25N BETWEEN 52W-62W. SOME OF THE NWP MODELS CONTINUE TO DEVELOP A WEAK TROUGH OR LOW AT THE SFC IN THIS VICINITY SW OF BERMUDA. MUCH OF THE E ATLC N OF 17N AND E OF 50W IS DOMINATED BY LARGE SCALE UPPER RIDGING...MODERATE TRADES...AND FAIR WEATHER. $$ WILLIS