000 AXNT20 KNHC 110502 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU OCT 11 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 0345 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 59W S OF 16N MOVING W 15-20 KT. THIS WAVE HAS VIRTUALLY NO SATELLITE SIGNATURE WITH ANY SHOWERS ACTIVITY IN THE VICINITY DUE TO AN UPPER LEVEL FEATURES. TROPICAL WAVE ALONG 67W/68W S OF 18N. THIS WAVE HAS BEEN RELOCATED SEVERAL TIMES IN THE PAST COUPLE OF DAYS QUESTIONING THE VALIDITY OF THE CURRENT LOCATION. WAVE IS MOVING INTO A BROAD AREA OF SW AND WILL BECOME EVEN MORE DIFFICULT TO TRACK IN THE COMING DAYS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N13W 7N29W 9N51W 10N63W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION IS FROM 2N-10N BETWEEN 20W-40W AND FROM 6N-11N BETWEEN 40W-51W. THE CONVECTION W OF 51W IS DUE TO AN UPPER LEVEL FEATURE...SEE BELOW. DISCUSSION... GULF OF MEXICO... BROAD DEEP LAYERED TROUGH COVERS MUCH OF THE GULF ANCHORED BY A LARGE UPPER LOW JUST S OF THE GREAT LAKES AREA EXTENDING AN ASSOCIATED COLD FRONT INTO THE GULF ACROSS NE FLORIDA ENTERING THE GULF JUST N OF TAMPA EXTENDING WSW TO THE COAST OF MEXICO JUST N OF TAMPICO. DUE TO DRY CONTINENTAL AIR FILTERING S OVER THE GULF...THERE IS ONLY WIDELY ISOLATED SHOWERS ALONG THE FRONTAL BOUNDARY. BROAD UPPER RIDGE ANCHORED OVER MEXICO IS REINFORCING THE DRY AIR OVER INTO THE GULF. AN UPPER RIDGE EXTENDS EASTWARD ACROSS S MEXICO INTO THE CARIBBEAN PRODUCING UPPER DIFFLUENCE ACROSS THE FAR S GULF GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE THE BAY OF CAMPECHE S OF 21N AND IN THE YUCATAN CHANNEL. THUS THE REMAINDER OF THE GULF REMAINS RATHER CLEAR TONIGHT. CARIBBEAN SEA... A WEAKENING 1005 MB LOW REMAINS INLAND OVER BELIZE BUT IS BEGINNING TO LOSE DEFINITION. A BROAD UPPER RIDGE EXTENDS ACROSS S MEXICO AND THE YUCATAN PENINSULA EXTENDING A RIDGE AXIS THROUGH THE WINDWARD PASSAGE COVERING THE CARIBBEAN TO NEAR 68W. UPPER DIFFLUENCE AND AN ABUNDANCE OF TROPICAL MOISTURE ARE GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 150 NM OF LINE FROM HAITI NEAR 19N73W TO OFF THE COAST OF HONDURAS NEAR 17N85W. AN UPPER RIDGE EXTENDING FROM AN UPPER HIGH IN THE W TROPICAL ATLC EXTENDS ACROSS THE LESSER ANTILLES TO 65W INDUCING AN UPPER TROUGH BETWEEN 65W-68W AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS W OF 67W TO OVER THE LESSER ANTILLES. LOW LEVEL AND UPPER LEVEL CONVERGENCE IS GENERATING SCATTERED SHOWERS/ THUNDERSTORMS OVER THE FAR SW CARIBBEAN S OF 11N W OF 81W TO OVER W PANAMA AND ALL OF COSTA RICA. ATLANTIC OCEAN... THE DEEP LAYERED TROUGH OVER THE E US INTO THE GULF OF MEXICO HAS MOVED INTO THE W ATLC W OF 74W WITH THE ASSOCIATED COLD FRONT EXTENDING ALONG THE COAST FROM NORTH CAROLINA ACROSS FLORIDA NEAR JACKSONVILLE AND INTO THE GULF OF MEXICO. DUE TO DRY CONTINENTAL AIR FILTERING E OFF THE COAST OF THE US...NO SHOWER ACTIVITY IS NOTED. THE UPPER RIDGE FROM THE CARIBBEAN EXTENDS THROUGH THE WINDWARD PASSAGE TO NEAR 25N63W WITH ENOUGH DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 28N BETWEEN 64W-78W. WEAK UPPER LEVEL TROUGH EXTENDS FROM AN UPPER LOW NEAR 31N62W SW TO 27N63W WITH A WEAK 1013 MB SURFACE LOW TO THE E NEAR 29N55W AND A SURFACE TROUGH EXTENDING SW TO 26N60W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 27N-32N BETWEEN 50W-55W. BROAD UPPER HIGH IS IN THE W TROPICAL ATLC NEAR 15N55W COVERING THE AREA FROM 40W ACROSS THE LESSER ANTILLES INTO THE FAR E CARIBBEAN. UPPER DIFFLUENCE AND AN ABUNDANCE OF TROPICAL MOISTURE ARE GENERATING SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS FROM 9N-17N W OF 51W TO ACROSS THE LESSER ANTILLES. AN UPPER TROUGH COVERS THE E ATLC EXTENDING FROM AN UPPER LOW JUST N OF THE CANARY ISLANDS NEAR 31N16W INTO THE E TROPICAL ATLC ACROSS THE CAPE VERDE ISLANDS THEN SW TO NEAR 10N34W AND COVERS THE REMAINDER OF THE ATLC. A SMALL SURFACE 1012 MB LOW HAS FORMED BENEATH THIS UPPER LOW NEAR 32N16W WITH SCATTERED SHOWERS WITHIN 120/150 NM OF THE SURFACE LOW. A SURFACE RIDGE COVERS THE REMAINDER OF THE E ATLC INTO THE CENTRAL ATLC EXTENDING FROM A HIGH WELL N OF THE REGION THROUGH 32N28W SW TO NEAR 20N56W. $$ WALLACE