000 AXNT20 KNHC 121056 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON NOV 12 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 66W/67W S OF 14N MOVING W NEAR 20 KT. WAVE REMAINS EMBEDDED WITHIN A SURGE OF AFRICAN DUST THAT IS NOW OVER THE E CARIBBEAN. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 13N BETWEEN 65W-69W INCLUDING THE ABC ISLANDS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 8N22W 8N38W 7N52W 7N60W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERS THE AREA FROM 2N-11N BETWEEN 11W-28W AND WITHIN 90/120 OT HE ITCZ AXIS FROM 37W-45W. DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE EXTENDS FROM THE W CARIBBEAN ACROSS THE YUCATAN NEAR 21N88W TO OVER THE MISSISSIPPI VALLEY WITH DRY STABLE AIR COVERING THE ENTIRE GULF. A SURFACE RIDGE EXTENDS OVER THE GULF INTO THE W ATLC ANCHORED OVER NORTH CAROLINA IS KEEPING THE W GULF IN RETURN FLOW AND PRODUCING SOME ISOLATED LOW LEVEL SHOWERS MAINLY N OF 27N W OF 90W TO INLAND OVER LOUISIANA. OTHERWISE MOSTLY FAIR SKIES DOMINATE THE GULF AGAIN THIS MORNING. CARIBBEAN SEA... THE MAIN FOCUS TONIGHT REMAINS THE 1006 MB LOW IN THE SW CARIBBEAN NEAR 11N82W WITH A SURFACE TROUGH EXTENDING N ALONG 16N82W TO THE CAYMAN ISLANDS NEAR 20N81W. THE LOW LEVEL CENTER IS PARTIALLY EXPOSED AS THE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N AND W OF THE LOW WITHIN 75/90 NM OF LINE FROM OVER NICARAGUA NEAR 13N84W TO 18N80W. THIS SYSTEM IS EXPECTED TO CONTINUE TO DRIFT WESTWARD AND MOVE INLAND OVER CENTRAL AMERICA LATER TODAY WITH NO SIGNIFICANT DEVELOPMENT. HOWEVER...IT COULD PRODUCE LOCALLY HEAVY RAINFALL OVER PORTIONS OF NICARAGUA AND HONDURAS OVER THE NEXT COUPLE OF DAYS. UPPER RIDGE EXTENDS ACROSS THE CARIBBEAN FROM AN UPPER HIGH OVER THE LESSER ANTILLES NEAR 15N62W. THIS IS PROVIDING ENOUGH UPPER LEVEL DIFFLUENCE TO GENERATE OF SCATTERED SHOWERS/THUNDERSTORMS WITHIN 60 NM OF LINE FROM 15N80W TO OFF THE COAST OF COLOMBIA NEAR 11N76W WITH CLUSTERS OF SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS DOTTING THE REMAINDER OF THE W CARIBBEAN S OF 20N BETWEEN 75W-85W. AFRICAN DUST IS FILTERED OVER THE E CARIBBEAN E OF 68W WITH AN AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS PRECEDING IT FROM 14N-16N BETWEEN 69W-73W. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE W ATLC WITH THE UPPER LOW OVER THE N CANADIAN MARITIMES AND EXTENDING W OF 50W TO THE E COAST OF FLORIDA. THE ASSOCIATED COLD FRONT EXTENDS TO 32N56W WITH A SURFACE TROUGH EXTENDING INTO THE REGION ALONG 27N67W OVER THE BAHAMA ISLANDS TO THE E COAST OF FLORIDA NEAR 25N80W WITH BROKEN TO OVERCAST LOW/MID CLOUDS AND ISOLATED SHOWERS N OF THE SURFACE TROUGH. A REMNANT SURFACE TROUGH FROM AN UPPER SYSTEM THAT IS WELL N OF THE REGION EXTENDS INTO THE CENTRAL ATLC NEAR 32N49W SW ALONG 24N58W TO OVER HISPANIOLA NEAR 19N71W. SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS ARE S OF 22N TO OVER HISPANIOLA AND E CUBA BETWEEN 66W-75W. AN UPPER HIGH IS OVER THE LESSER ANTILLES NEAR 15N62W EXTENDING AN UPPER RIDGE NE ALONG 23N49W TO BEYOND 32N40W WITH ENOUGH DIFFLUENCE TO GENERATE SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 24N56W TO BEYOND 32N43W. A WEAK UPPER TROUGH IS UNDERCUTTING THE UPPER RIDGE ABOVE EXTENDING FROM 15N45W TO 7N52W. A NARROW UPPER TROUGH IS OVER THE FAR E ATLC N OF 20N E OF 24W TO INLAND OVER W AFRICA WITH A SURFACE TROUGH EXTENDING THROUGH 32N26W S TO 26N27W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150 NM E OF THE TROUGH. A SURFACE RIDGE IS BUILDING SOUTHWARD OVER THE E/CENTRAL ATLC BETWEEN THE ABOVE SURFACE TROUGHS TO 20N FROM 30W-48W WITH A WEAK 1018 MB HIGH LOCATED NEAR 28N38W. THE TYPICAL E/W UPPER RIDGE CROSS THE TROPICAL ATLC E OF 40W WITH THE AXIS ALONG 7N/8N. BROAD AREA OF AFRICAN DUST COVERS MUCH OF THE TROPICS S OF 22N FROM 30W INTO THE E CARIBBEAN. $$ WALLACE