000 AXNT20 KNHC 230532 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON JUL 23 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 ALONG 29W/30W S OF 18N WITH A 1010MB LOW ALONG THE WAVE NEAR 13N MOVING W 15 KT. BROAD INVERTED-V SIGNATURE IS OBSERVED WITH A SMALL SURFACE LOW. SCATTERED MODERATE/STRONG CONVECTION IS E OF THE WAVE FROM 8N-11N BETWEEN 25W-30W. E CARIBBEAN TROPICAL WAVE IS ALONG 67W S OF 20N MOVING W NEAR 20 KT. BROAD LOW LEVEL INVERTED-V SIGNATURE IS OBSERVED EXTENDING FROM E OF THE LESSER ANTILLES INTO THE CENTRAL CARIBBEAN. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 14N-20N BETWEEN 57W-71W. W CARIBBEAN TROPICAL WAVE IS ALONG 83W/84W S OF 21N MOVING W 15 KT. WELL DEFINED LOW LEVEL INVERTED-V SIGNATURE IS OBSERVED MOVING OVER CENTRAL AMERICA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ENHANCED BY AN UPPER LEVEL RIDGE AND COVER THE AREA W OF 80W TO OVER CENTRAL AMERICA AND THE YUCATAN. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 15N17W 13N28W 7N41W 9N62W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 5N-9N BETWEEN 43W-47W. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 8N-12N E OF 21W TO THE COAST OF AFRICA. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS OVER THE E US AND THE NW ATLC INTO THE GULF OF MEXICO N OF 26N E OF 90W WITH A RE-ENFORCING UPPER HIGH OVER THE OVER THE CENTRAL PLAIN STATES FORCING DRY STABLE AIR OVER THE NW GULF. THE ASSOCIATED FRONTAL BOUNDARY EXTENDS FROM THE W ATLC ACROSS CENTRAL FLORIDA NEAR LAKE OKEECHOBEE TO A SMALL 1012 MB LOW IN THE E GULF NEAR 27N85W WITH A SECOND FRONTAL BOUNDARY EXTENDING FROM A 1013 MB LOW OFF THE N GULF COAST NEAR 29N88W TO OVER TEXAS NEAR HOUSTON. A WEAK UPPER LOW IS OVER THE SW GULF NEAR 22N94W. ALL THIS IS KEEPING THE GULF RATHER ACTIVITY TONIGHT WITH SCATTERED SHOWERS/THUNDERSTORMS OVER THE E GULF WITH WIDELY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE W GULF S OF 26N AND SOME SCATTERED THUNDERSTORMS WITHIN 60 NM OF THE FRONTAL BOUNDARY ALONG THE COAST OF TEXAS. CARIBBEAN SEA... THE TROPICAL WAVES IN THE CARIBBEAN ARE RESPONSIBLE FOR MOST OF THE ACTIVITY IN THE CARIBBEAN TONIGHT. AN UPPER HIGH JUST N OF HISPANIOLA IS GIVING THE E CARIBBEAN UPPER EASTERLY FLOW AND A STRONG UPPER HIGH IN THE CENTRAL CARIBBEAN NEAR 16N79W DOMINATES THE REMAINDER OF THE AREA. THIS UPPER HIGH IS ENHANCING THE ACTIVITY ASSOCIATED WITH THE W CARIBBEAN TROPICAL WAVE AND PRODUCING SCATTERED SHOWERS/THUNDERSTORMS INLAND AND WITHIN 90 NM ALONG THE COAST OF E CUBA FROM 77W-80W. OTHERWISE THERE IS ONLY ISOLATED SHOWERS OVER THE SW CARIBBEAN WITHIN 75 NM OF LINE FROM COLOMBIA NEAR 11N74W TO NE NICARAGUA NEAR 14N84W. ATLANTIC OCEAN... DEEP LAYERED TROUGH OVER THE E US AND GULF OF MEXICO EXTENDS INTO THE NW ATLC N OF 27N W OF 74W WITH THE ASSOCIATED FRONTAL BOUNDARY EXTENDING INTO THE REGION NEAR 32N73W ACROSS FLORIDA INTO THE GULF OF MEXICO NEAR LAKE OKEECHOBEE. THE UPPER HIGH N OF HISPANIOLA NEAR 21N69W COVERS THE REMAINDER OF THE W ATLC W OF 55W GIVING THE FAR W ATLC SCATTERED SHOWERS/THUNDERSTORMS S OF THE FRONTAL BOUNDARY W OF 72W WITH THE HIGHEST CONCENTRATION OF THUNDERSTORMS OVER THE CENTRAL BAHAMAS. AN UPPER LOW JUST N OF BERMUDA IS INTERACTING WITH THE SAME UPPER HIGH TO GIVE A SMALL AREA SCATTERED SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 26N-30N BETWEEN 60W-69W. VERY LARGE UPPER LOW COVERS THE CENTRAL ATLC CENTERED N OF THE REGION NEAR 34N45W AND COVERS THE AREA FROM 31W-55W. AN UPPER RIDGE COVERS THE E ATLC E OF 30W EXTENDING E/W ALONG 22W. A SURFACE RIDGE AND DRY STABLE AIR COVERS THE ATLC E OF 60W WITH ONLY FAIR WEATHER CLOUDS OVER THE AREA. $$ WALLACE