000 AXNT20 KNHC 040555 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT OCT 04 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 0315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 19W/20W S OF 17N MOVING W NEAR 10 KT. WAVE AS AT THE LEADING EDGE OF A DEEP LAYERED MOISTURE AS INDICATED BY MIMIC TPW ANIMATION. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE FROM 15N-19N BETWEEN 17W-20W. TROPICAL WAVE IS ALONG 49W S OF 18N MOVING W 10-15 KT. WAVE HAS BECOME TILTED OVER THE PASS 24 HOURS WITH THE SOUTHERN PORTION MOVING FASTER THEN THE NORTH BASED ON MIMIC TPW ANIMATION... SATELLITE IMAGERY...AND LATEST QUIKSCAT PASS. THIS WAVE MAY BE ADJUSTED ON THE 0600 UTC ANALYSIS. SCATTERED STRONG CONVECTION IS WITHIN 90 NM OF LINE FROM 16N47W TO 18N44W. TROPICAL WAVE IS TILTED FROM 17N59W TO 9N61W MOVING W 10-15 KT. WAVE HAS BECOME TILTED IS IT APPROACHES THE UPPER LOW MOVING OVER THE E CARIBBEAN. THIS UPPER LOW IS ALSO ENHANCING THE ACTIVITY IN THE VICINITY OF THIS WAVE. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 13N15W 8N32W 10N47W 10N62W. LARGE CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 120 NM OF LINE FROM 10N21W TO 3N35W WITH SMALLER CLUSTERS WITHIN 75 NM OF LINE FROM 15N21W TO 8N34W. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF 14N FROM 51W-56W AND CLUSTERS OF SIMILAR CONVECTION FROM 4N-15N BETWEEN 35W-43W. ...DISCUSSION... GULF OF MEXICO... A DEEP LAYERED TROUGH CONTINUES TO DOMINATE THE GULF WITH DRY STABLE AIR REMAINING OVER THE GULF WATERS WITH THE EXCEPTION OF S FLORIDA AND THE FLORIDA STRAITS S OF 26N E OF 83W. THIS DEEP TROUGH CONTINUES TO SUPPORT A QUASI-STATIONARY FRONT EXTENDING FROM THE W ATLC THROUGH THE FLORIDA STRAITS TO THE N COAST OF CUBA NEAR 23N83W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 25N E OF 83W. LOW LEVEL CONVERGENCE CONTINUES IN THE BAY OF CAMPECHE GIVING THE AREA LOW CLOUDS AND POSSIBLE ISOLATED SHOWERS S OF 21N W OF 91W. THE REMAINDER OF THE GULF REMAINS RATHER CLEAR AGAIN TONIGHT WITH DEW POINTS SLOWLY ON THE RISE BUT STILL IN THE 60 DEG RANGE ACROSS THE GULF N OF 26N. CARIBBEAN SEA... A WEAKENING SURFACE TROUGH EXTENDS FROM 20N85W THROUGH A 1011 MB SURFACE LOW NEAR 18N86W TO INLAND OVER CENTRAL HONDURAS. AN UPPER RIDGE ANCHORED JUST S OF THE CAYMAN ISLANDS COVERS THE W CARIBBEAN AND COUPLED WITH THE DEEP LAYERED TROUGH OVER THE GULF OF MEXICO CONTINUES TO PROVIDE MOIST UPPER FLOW OVER THE NW CARIBBEAN AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE AREA BETWEEN A LINE FROM E CUBA NEAR 20N76W TO PANAMA NEAR 9N78W AND A LINE FROM W CUBA NEAR 22N84W TO THE YUCATAN NEAR 20N87W. AN UPPER LOW IS OVER THE E CARIBBEAN NEAR 16N65W COVERING THE AREA N OF 13N E OF 74W TO OVER THE LESSER ANTILLES. THIS UPPER FLOW IS DRAWING THE DRIER STABLE AIR FROM THE W ATLC OVER THE N/CENTRAL CARIBBEAN. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER THE LESSER ANTILLES S OF 20N TO OVER SOUTH AMERICA BETWEEN 59W-63W INCLUDING THE VIRGIN ISLANDS. SCATTERED LOW LEVEL SHOWERS DOT THE CENTRAL CARIBBEAN USHERED IN ON MODERATE/STRONG EASTERLY TRADE WINDS. ATLANTIC OCEAN... DEEP LAYERED TROUGH OVER THE FAR E US AND GULF OF MEXICO CONTINUES TO PUSH NE OVER THE CANADIAN MARITIMES CLIPPING THE W ATLC WITH A STATIONARY FRONT ENTERING THE REGION FROM A 1016 MB LOW NEAR 32N73W ALONG 28N76W EXTENDING THROUGH THE FLORIDA STRAITS NEAR 25N80W TO THE N COAST OF CUBA. DRY STABLE AIR REMAINS N OF 27N W OF 75W TO OVER THE SE US WITH MOIST SW UPPER FLOW FROM THE CARIBBEAN ACROSS CUBA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 26N W OF 75W AND ISOLATED SHOWERS WITHIN 120 NM OF THE REMAINDER OF THE FRONTAL BOUNDARY. AN UPPER RIDGE COVERS THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC ANCHORED NEAR 32N58W SUPPORTING DRY STABLE AIR ACROSS THE AREA. THE UPPER LOW THAT UNDERCUT THIS UPPER RIDGE IS CENTERED IN THE CARIBBEAN NEAR 16N65W AND COVERS THE SW ATLC. A SECOND CUT-OFF UPPER LOW IN THE CENTRAL ATLC IS CENTERED NEAR 22N48W GENERATING ISOLATED SHOWERS FROM 20N-26N BETWEEN 44W-50W. A SURFACE TROUGH IS JUST TO THE N EXTENDING FROM 31N45W TO 24N47W. DIFFLUENCE ALOFT TO THE SE OF THIS UPPER LOW IS GENERATING SCATTERED MODERATE/STRONG CONVECTION FROM 17N-22N BETWEEN 38W-45W. AN UPPER TROUGH IS OVER THE NE ATLC EXTENDING THROUGH 32N16W SW TO 26N24W COVERING THE AREA N OF 24N E OF 26W TO OVER NW AFRICA. THE TYPICAL E/W UPPER RIDGE HAS BECOME DISRUPTED BY THE UPPER LOW IN THE CENTRAL ATLC AND NOW EXTENDS E ALONG 15N TO 30W. $$ WALLACE