000 AXNT20 KNHC 120534 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED NOV 12 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 0515 UTC. ...THE ITCZ... THE AXIS IS ANALYZED ALONG 10N13W 7N27W 8N46W 6N58W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 180 NM N OF THE ITCZ FROM 36W-42W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVER THE REMAINDER OF THE AREA FROM 3N-12N BETWEEN 32W-46W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE COVERS THE GULF EXTENDING FROM THE CARIBBEAN. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR REMAIN OVER THE GULF WITH THE EXCEPTION OF UPPER LEVEL MOISTURE STREAMING ACROSS MEXICO TO OVER THE N GULF COAST STATES CLIPPING THE FAR NW GULF. A SURFACE RIDGE COVERS THE NE GULF ANCHORED OVER VIRGINIA WITH A COLD FRONT APPROACHING THE NW GULF BUT FOR NOW REMAINS INLAND OVER TEXAS. THIS FRONT WILL MOVE INTO THE GULF WATERS LATER THIS MORNING. RETURN FLOW AROUND THE SURFACE RIDGE COUPLED WITH THE APPROACHING FRONT IS GIVING THE THE FAR NW GULF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 26N W OF 93W TO INLAND OVER W LOUISIANA/E TEXAS. ISOLATED SHOWERS ARE IN THE FLORIDA STRAITS AND OVER S FLORIDA S OF 26N E OF 86W BROUGHT IN BY A SURFACE LOW IN THE N CARIBBEAN. OTHERWISE THE REMAINDER OF THE GULF REMAINS CLEAR TONIGHT. CARIBBEAN SEA... BROAD UPPER RIDGE DOMINATES THE W CARIBBEAN ANCHORED INLAND OVER NICARAGUA EXTENDING A RIDE AXIS ACROSS CUBA INTO THE W ATLC. AN UPPER TROUGH EXTENDS OVER THE E CARIBBEAN FROM AN UPPER LOW N OF PUERTO RICO. ALTHOUGH THE ENTIRE CARIBBEAN IS DOMINATED BY MODERATE/STRONG SUBSIDENCE...UPPER DIFFLUENCE OVER THE SW CARIBBEAN IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 13N W OF 81W TO INLAND OVER PANAMA...COSTA RICA...AND S NICARAGUA. A WEAK SURFACE 1011 MB LOW IS ALONG THE S COAST OF CUBA NEAR NEAR 21N79W WITH A SURFACE TROUGH EXTENDING FROM JAMAICA THROUGH THE LOW ACROSS CUBA TO OVER THE N BAHAMA ISLANDS GENERATING ISOLATED SHOWERS N OF 20N BETWEEN 77W-86W AND A POSSIBLE THUNDERSTORMS WITHIN 30 NM OF THE SURFACE LOW. ISOLATED SHOWERS ARE POSSIBLE OVER THE E CARIBBEAN E OF 74W. OTHERWISE THE REMAINDER OF THE CARIBBEAN REMAINS TRANQUIL TONIGHT. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE W CARIBBEAN EXTENDS INTO THE W ATLC ACROSS CUBA NEAR 22N80W N TO 32N76W. A WEAK SURFACE TROUGH IS BENEATH THIS UPPER RIDGE EXTENDING FORM THE SURFACE LOW ALONG THE S COAST OF CUBA NEAR 21N79W ACROSS THE N BAHAMA ISLANDS TO 29N74W. ISOLATED LOW LEVEL SHOWERS ARE OVER THE FAR W ATLC W OF 76W. AN UPPER TROUGH EXTENDS OVER THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC FROM ACROSS BERMUDA TO AN UPPER LOW NEAR 25N67W INTO THE THE E CARIBBEAN TO NEAR THE ABC ISLANDS. AN UPPER RIDGE TO THE E IS PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 21N-25N BETWEEN 60W-66W. AN UPPER LOW IS OVER THE E/CENTRAL N OF 23N FROM 32W-45W WITH A SURFACE 1014 MB LOW CENTERED NEAR 29N38W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE E OF THE SURFACE LOW FROM 27N-30N BETWEEN 34W-38W. A SECOND UPPER LOW IS IN THE W TROPICAL ATLC NEAR 15N50W WITH A SURFACE TROUGH TO THE N EXTENDING FROM 24N51W TO 18N56W. SCATTERED SHOWERS ARE WITHIN 180 NM EITHER SIDE OF THE SURFACE TROUGH. BROAD UPPER RIDGE COVERS THE ENTIRE E ATLC ANCHORED NEAR 10N30W PROVIDING UPPER DIFFLUENCE ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ. $$ WALLACE