000 AXNT20 KNHC 120519 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE DEC 12 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA... CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA... NORTHEASTERN 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. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N9W 4N22W 2N28W 1N40W EQ50W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1N-5N BETWEEN 12W-26W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N-7N BETWEEN 20W-34W. ...DISCUSSION... GULF OF MEXICO... BROAD MID/UPPER LEVEL TROUGH IS OVER THE CENTRAL US MOVING ACROSS THE MISSISSIPPI VALLEY AND THE NW GULF N OF 24N W OF 92W. LOW/MID LEVEL TROUGH REMAINS OVER THE CENTRAL GULF WITH A WEAK SURFACE TROUGH EXTENDING FROM S MEXICO/YUCATAN PENINSULA ACROSS THE E BAY OF CAMPECHE ALONG 20N92W N TO OFF THE LOUISIANA COAST NEAR 28N94W. THE REMAINDER OF THE GULF IS DOMINATED BY AN UPPER RIDGE WITH THE AXIS EXTENDING FROM THE CARIBBEAN ALONG 80W COVERING THE W ATLC AND E GULF DRAWING TROPICAL MOISTURE N ACROSS THE SE GULF TO 26N E OF 86W BRINGING SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS OVER THAT AREA. ALSO AT THE SURFACE...RIDGE THAT DOMINATES THE W ATLC EXTENDS OVER THE E US INTO THE GULF OF MEXICO. CARIBBEAN SEA... BROAD MID/UPPER LEVEL RIDGE DOMINATES THE CARIBBEAN ANCHORED BY AN UPPER HIGH OVER NW VENEZUELA EXTENDING N INTO THE W ATLC ALONG 80W. THIS IS DRAWING TROPICAL MOISTURE N OVER THE NW CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 17N W OF 80W. THIS UPPER LEVEL FLOW COMBINED WITH MODERATE/ STRONG EASTERLY TRADE WINDS ACROSS THE CARIBBEAN ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N W OF 80W. ALTHOUGH THE REMAINDER OF THE CARIBBEAN IS UNDER DRY UPPER AIR AND MODERATE/STRONG SUBSIDENCE...LOW LEVEL MOISTURE IS EVIDENT WITH ISOLATED SHOWERS S OF 17N E OF 74W TO OVER THE LESSER ANTILLES. ATLANTIC OCEAN... BROAD MID/UPPER LEVEL RIDGE FROM THE CARIBBEAN COVER THE FAR W ATLC W OF 67W INTO THE GULF OF MEXICO. DEEP LAYERED TROUGH COVERS THE W/CENTRAL ATLC N OF 23N BETWEEN 48W-67W. THE ASSOCIATED COLD FRONT ENTERS THE REGION NEAR 32N50W EXTENDING SW TO 23N61W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 250 NM E OF THE FRONT. A NARROW UPPER RIDGE EXTENDS FROM THE W TROPICAL ATLC NEAR 20N49W NE TO BEYOND 32N41W. AN UPPER LOW IS IN THE E ATLC NEAR 23N32W COVERING THE AREA FROM 14N-30N BETWEEN 23W-40W WITH AN UPPER RIDGE OVER THE SE ATLC ALONG THE COAST OF AFRICA. THE UPPER LOW OVER W AFRICA HAS BECOME CUT-OFF AND IS MOVING FURTHER E. A WEAK SURFACE TROUGH EXTENDS FROM 19N44W TO 13N47W BUT IS EMBEDDED WITHIN DRY UPPER AIR AND STRONG SUBSIDENCE. BROAD SURFACE RIDGE DOMINATES THE E ATLC. $$ WALLACE