000 AXNT20 KNHC 231035 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 33W/34W S OF 20N MOVING W 20 KT. THE SURFACE LOW IS NO LONGER DISCERNIBLE. BROAD INVERTED-V SIGNATURE IS OBSERVED COVERING THE AREA FROM 28W-42W. SCATTERED MODERATE CONVECTION ON THE S PORTION OF THE WAVE WITHIN 60 NM OF 8N FROM 31W-35W. E CARIBBEAN TROPICAL WAVE IS ALONG 69W S OF 19N MOVING W NEAR 20 KT. BROAD LOW LEVEL INVERTED-V SIGNATURE IS OBSERVED EXTENDING FROM E OF THE LESSER ANTILLES TO THE CENTRAL CARIBBEAN. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 14N-18N BETWEEN 57W-73W. W CARIBBEAN TROPICAL WAVE IS ALONG 85W/86W S OF 21N MOVING W 15-20 KT. LOW LEVEL INVERTED-V SIGNATURE IS OBSERVED MOVING OVER THE NW CARIBBEAN...CENTRAL AMERICA...AND THE YUCATAN PENINSULA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ENHANCED BY AN UPPER LEVEL RIDGE AND COVER THE AREA N OF 12N TO OVER CUBA W OF 82W TO OVER CENTRAL AMERICA AND THE YUCATAN. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 16N16W 10N26W 11N35W 8N41W 8N52W 7N58W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-10N BETWEEN 24W-30W AND FROM 6N-8N BETWEEN 45W-49W. SMALL CLUSTERS OF SIMILAR CONVECTION ARE OFF THE COAST OF AFRICA WITHIN 120 NM OF LINE FROM 5N11W TO 12N21W. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS OVER THE E US AND THE NW ATLC INTO THE GULF OF MEXICO N OF 25N E OF 90W WITH A RE-ENFORCING UPPER HIGH OVER THE OVER THE CENTRAL PLAIN STATES FORCING AIR S OVER THE NW GULF. THE ASSOCIATED FRONTAL BOUNDARY EXTENDING FROM THE W ATLC IS BECOMING NEAR STATIONARY TO 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 ALONG 27N92W TO OVER TEXAS NEAR HOUSTON. A PREFRONTAL TROUGH HAS BECOME NEAR STATIONARY EXTENDING FROM THE 1013 MB LOW ALONG 26N92W TO THE COAST JUST S BROWNSVILLE TEXAS. SMALL WEAK UPPER LOW IS OVER THE SW GULF NEAR 22N95W. ALL THIS IS KEEPING THE GULF RATHER ACTIVITY THIS MORNING WITH CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS OVER THE GULF E OF 92W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE GULF W OF 92W. CARIBBEAN SEA... THE TROPICAL WAVES IN THE CARIBBEAN ARE RESPONSIBLE FOR MOST OF THE ACTIVITY IN THE CARIBBEAN THIS MORNING. AN UPPER HIGH IS ALONG THE N COAST OF HISPANIOLA IS GIVING THE E CARIBBEAN UPPER EASTERLY FLOW AND A SECOND STRONG UPPER HIGH IN THE CENTRAL CARIBBEAN NEAR 16N80W DOMINATES THE REMAINDER OF THE AREA. THE SECOND UPPER HIGH IS ENHANCING THE ACTIVITY ASSOCIATED WITH THE W CARIBBEAN TROPICAL WAVE AND IN ADDITION IS PRODUCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE SW CARIBBEAN WITHIN 75 NM OF LINE FROM COLOMBIA NEAR 11N74W TO INLAND OVER NE NICARAGUA NEAR 15N84W. 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 A ASSOCIATED NEAR STATIONARY FRONTAL BOUNDARY EXTENDING INTO THE REGION NEAR 32N72W ACROSS FLORIDA INTO THE GULF OF MEXICO NEAR LAKE OKEECHOBEE. THE UPPER HIGH ALONG THE N COAST OF HISPANIOLA IS NEAR 19N69W WITH A RIDGE AXIS EXTENDING N TO 31N64W COVERING THE REMAINDER OF THE W ATLC W OF 58W GIVING THE AREA FROM 22N TO THE FRONTAL BOUNDARY BETWEEN 73W-78W SCATTERED MODERATE/ISOLATED STRONG CONVECTION AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF THE FRONTAL BOUNDARY. AT THE BASE OF AN UPPER LOW THAT IS N OF BERMUDA IS ENOUGH DIFFLUENCE TO GIVE A SMALL AREA SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS FROM 25N-31N BETWEEN 60W-69W. AN UPPER LOW IS IN THE CENTRAL ATLC CENTERED NEAR 25N52W COVERING THE AREA FROM 42W-58W WITH A SECOND UPPER LOW NEAR 31N45W. AN UPPER RIDGE COVERS THE E ATLC E OF 40W EXTENDING E/W ALONG 22W. A SURFACE RIDGE AND DRY STABLE AIR COVERS THE ATLC E OF 60W ANCHORED BY A 1032 MB HIGH WELL N OF THE REGION PRODUCING ONLY FAIR WEATHER CLOUDS ACROSS THE REMAINDER OF THE AREA. $$ WALLACE