000 AXNT20 KNHC 210502 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT JUL 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS TITLED FROM 20N47W 13N51W 5N54W MOVING W 15-20 KT. BROAD WAVE LOW LEVEL INVERTED-V CURVATURE COVERING THE AREA FROM 42N-57N. NO ASSOCIATED DEEP CONVECTION WITH ISOLATED SHOWERS FROM 13N-18N BETWEEN 50W-53W. TROPICAL WAVE IN THE E CARIBBEAN IS ALONG 72W S OF 18N MOVING W 15 KT. WAVE HAS WEAK LOW AMPLITUDE INVERTED-V CURVATURE OVER THE CENTRAL CARIBBEAN. HEAVY RAINS WITH EMBEDDED THUNDERSTORMS IS N OF 17N FROM 69W-73W COVERING MOST OF HISPANIOLA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 13N TO INLAND OVER COLOMBIA FROM 72W-75W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 14N15W 7N31W 13N47W 9N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10N-13N E OF 19W TO THE COAST OF AFRICA. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 5N-10N BETWEEN 16W-33W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL HIGH IS INLAND OVER N/CENTRAL MEXICO WITH THE UPPER RIDGE COVERING THE GULF W OF 88W WITH THE ASSOCIATED DEEP CONVECTION INLAND OVER S TEXAS AND MEXICO. SHORTWAVE UPPER TROUGH EXTENDS FROM THE W ATLC ACROSS NE FLORIDA INTO THE NE GULF TO NEAR 27N85W BRINGING SCATTERED SHOWERS/THUNDERSTORMS S TO WITHIN 90 NM ALONG THE N GULF COAST E OF CENTRAL LOUISIANA TO ACROSS THE FLORIDA PANHANDLE. CUT-OFF UPPER LOW THAT IS NW OF THE CAYMAN ISLANDS COVERS THE GULF S OF 26N E OF 85W INTO THE W ATLC GENERATING SOME ISOLATED SHOWERS OVER THE FLORIDA STRAITS. OTHERWISE A WEAK SURFACE RIDGE COVERS THE NW GULF WITH A 1017 MB HIGH OFF SW LOUISIANA NEAR 28N92W. CARIBBEAN SEA... SMALL CUT-OFF UPPER LOW REMAINS CENTERED NW OF THE CAYMAN ISLANDS NEAR 21N82W COVERING THE AREA N OF 17N FROM 78W TO THE YUCATAN CHANNEL GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM N OF 20N FROM 77W-81W AND N OF 15N BETWEEN 74W-77W. BROAD UPPER HIGH ANCHORED JUST E OF THE LESSER ANTILLES EXTENDS A RIDGE AXIS E ACROSS THE REMAINDER OF THE CARIBBEAN. THE HEAVY RAINS AND THUNDERSTORMS OVER HISPANIOLA ARE ASSOCIATED WITH THE TROPICAL WAVE. THE ITCZ AXIS IN THE E PACIFIC REGION EXTENDS ACROSS PANAMA AND COSTA RICA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 45 NM ALONG THE COAST OF PANAMA AND W COLOMBIA. TRADE WINDS HAVE WEAKENED OVER THE PAST 24 HOURS WITH MODERATE EASTERLY TRADE WINDS CONTINUING ACROSS THE S/CENTRAL CARIBBEAN. ATLANTIC OCEAN... THE PRIMARY FOCUS TONIGHT IS THE SURFACE TROUGH THAT EXTENDS FROM THE N COAST OF HISPANIOLA TO NEAR 26N66W GENERATING A BROAD AREA OF SCATTERED SHOWERS/THUNDERSTORMS WITHIN 150-175 NM OF LINE FROM 21N66W TO 28N61W AND HEAVY RAINS WITH EMBEDDED THUNDERSTORMS S OF 21N TO OVER HISPANIOLA BETWEEN 67W-72W. OTHERWISE...SHORTWAVE UPPER TROUGH EXTENDS THROUGH 32N76W ACROSS NE FLORIDA GENERATING SCATTERED SHOWERS/THUNDERSTORMS NW OF A LINE FROM 30N79W TO BEYOND 32N73W. CUT-OFF UPPER LOW NW OF THE CAYMAN ISLANDS CLIPS THE SW ATLC PRODUCING WIDELY ISOLATED SHOWERS BETWEEN CUBA AND THE BAHAMA ISLANDS. AN UPPER LOW REMAINS IN THE W/CENTRAL ATLC NEAR 27N68W COVERING THE AREA N OF 22N FROM 63W-73W. UPPER HIGH JUST E OF THE LESSER ANTILLES NEAR 16N59W EXTENDS A RIDGE AXIS N TO NEAR 28N59W ENHANCING THE SHOWERS/THUNDERSTORMS ASSOCIATED WITH THE SURFACE TROUGH MENTIONED ABOVE. AN UPPER TROUGH OVER THE CENTRAL ATLC TILTS NW/SE THROUGH 32N55W TO 21N45W WITH A VERY NARROW UPPER RIDGE BETWEEN THIS UPPER TROUGH AND THE UPPER LOW CENTERED NEAR 27N68W. ZONAL EASTERLY FLOW DOMINATES THE E ATLC E OF 40W. THE LAST VISIBLE SATELLITE IMAGES OF YESTERDAY SHOW AN AREA OF AFRICAN DUST FROM 15N-30W E OF 35W. THE REMAINDER OF THE ATLC CONTINUES TO BE DOMINATED BY A STRONG SURFACE RIDGE ANCHORED BY A 1035 MB HIGH CENTERED N OF THE REGION. $$ WALLACE