000 AXNT20 KNHC 292303 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN JUL 29 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2215 UTC. ...SPECIAL FEATURE... SURFACE TROUGH IS LOCATED FROM 33N71W ALONG 30N71W TO 27N74W. SYSTEM REMAINS POORLY ORGANIZED BUT STILL HAS SOME POTENTIAL FOR TROPICAL OR SUBTROPICAL DEVELOPMENT OVER THE COUPLE OF DAYS AS IT MOVES NORTH-NORTHEASTWARD AT 10-15 KT. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE E OF THE TROUGH AXIS WITHIN 120/150 NM OF LINE FROM 24N72W TO 33N67W AND COULD MOVE OVER BERMUDA LATER TONIGHT. ...TROPICAL WAVES... TROPICAL WAVE IS OVER THE E ATLC HAS BEEN SLIGHTLY RELOCATED TO THE E BASED ON VISIBLE SATELLITE IMAGERY AND UPPER AIR SOUNDINGS AND IS TILTED ALONG 23W/24W S OF 19W MOVING W NEAR 10 KT. BROAD LOW/MID LEVEL CYCLONIC ROTATION IS OBSERVED COVERING THE AREA FROM 19W-29W. ANY CONVECTION IN THE VICINITY IS EMBEDDED WITHIN THE ITCZ. TROPICAL WAVE IS OVER THE CENTRAL ATLC ALONG 48W/49W S OF 17N MOVING W NEAR 15 KT. WEAK WAVE COVERING A NARROW AREA FROM 46W-51W. ANY CONVECTION IN THE VICINITY IS EMBEDDED WITHIN THE ITCZ. TROPICAL WAVE IS OVER THE LESSER ANTILLES TILTED FROM 20N60W ALONG 13N62W TO INLAND OVER SOUTH AMERICA NEAR 6N61W MOVING W NEAR 15 KT. BROAD LOW LEVEL INVERTED-V CURVATURE COVERING THE AREA FROM 56W-65W. ISOLATED SHOWERS/ ARE MOVING ACROSS THE LESSER ANTILLES BUT NO ASSOCIATED DEEP CONVECTION IS NOTED. TROPICAL WAVE IS OVER THE BAY OF CAMPECHE ACROSS S MEXICO INTO THE E PACIFIC REGION ALONG 92W MOVING W NEAR 15 KT. WELL DEFINED LOW/MID LEVEL INVERTED-V CURVATURE IS NOTED IN THE E PACIFIC REGION. ANY ASSOCIATED DEEP CONVECTION IS WELL INLAND OVER S MEXICO AND IN THE E PACIFIC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 15N16W 10N27W 7N41W 9N50W 8N56W 9N60W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180/200 NM OF THE ITCZ AXIS FROM 40W-55W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 200 NM S OF THE ITCZ AXIS FROM 23W-37W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LOW IS OVER NW MEXICO EXTENDING N ACROSS THE LOWER CENTRAL PLAIN STATES AND THE DESERT SW GENERATING A LARGE AREA OF SHOWERS/THUNDERSTORMS OVER THAT AREA AND TO THE COAST OF TEXAS. A NARROW UPPER RIDGE EXTENDS FROM NE MEXICO ALONG THE TEXAS COAST TO SW LOUISIANA GIVING THE GULF W OF 87W NW UPPER FLOW. AN UPPER TROUGH EXTENDS OVER THE FAR SE US TO OVER FLORIDA TO CENTRAL CUBA AND INTO THE W ATLC GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE E GULF E OF 87W WITH THE HIGHEST CONCENTRATION S OF 27N. AT THE SURFACE...WEAK RIDGE EXTENDS FROM THE W ATLC ACROSS FLORIDA TO A 1015 MB HIGH IN THE CENTRAL GULF NEAR 27N89W. CARIBBEAN... THE NE UPPER FLOW FROM THE GULF OF MEXICO COVERS THE NW CARIBBEAN N OF 18N W OF 80W GENERATING SHOWERS/SCATTERED THUNDERSTORMS FROM OVER CUBA TO 20N W OF 81W TO OVER THE YUCATAN. AN UPPER RIDGE EXTENDS FROM COLOMBIA NEAR 10N75W NW TO OVER NICARAGUA AND HONDURAS NEAR 14N84W COVERING THE THE REMAINDER OF THE W CARIBBEAN W OF 72W. THE ITCZ EXTENDS FROM COLOMBIA ACROSS PANAMA AND COSTA RICA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS SW OF A LINE FROM PANAMA NEAR 9N78W TO OVER NICARAGUA NEAR 13N84W. WEAK UPPER LEVEL INVERTED TROUGH COUPLED WITH DRY STABLE AIR DOMINATES THE REMAINDER OF THE CARIBBEAN WITH SOME ISOLATED AFTERNOON THUNDERSTORMS THAT HAVE DEVELOPED OVER PUERTO RICO...HISPANIOLA...AND E CUBA MOVING W OVER THE COASTAL WATERS. ATLANTIC... SEE SPECIAL FEATURES FOR THE SURFACE TROUGH LOCATED OVER THE W ATLANTIC. UPPER LEVEL TROUGH THAT COVERS THE SE US ACROSS FLORIDA TO CUBA EXTENDS INTO THE W ATLC W OF 71W. AN UPPER HIGH IS E OF THE BAHAMAS NEAR 24N69W AND EXTENDS AN UPPER RIDGE NE OVER BERMUDA COVERING THE REMAINDER OF THE W ATLC. THIS IS ENHANCING THE CONVECTION DESCRIBED IN THE SPECIAL FEATURES ABOVE. BENIGN UPPER TROUGH/RIDGE/TROUGH/RIDGE COVERS THE ATLC FROM 30W-60W. AN E/W UPPER RIDGE EXTENDS FROM OFF AFRICA NEAR NEAR 30N E OT 30W COVERING THE REMAINDER OF THE E ATLC. MORE AFRICAN DUST COVERS THE ATLC E OF 30W AND IS BEING DRAWN BACK TO THE COAST OF AFRICA BY THE UPPER RIDGE. DRY STABLE AIR E OF 60W AND A SURFACE RIDGE E OF 70W ANCHORED BY A 1023 MB HIGH NEAR 33N52W DOMINATE THE ATLC GIVING THE AREA E OF 60W FAIR WEATHER THIS AFTERNOON. $$ WALLACE