000 AXNT20 KNHC 111120 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SUN NOV 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 58W S OF 13N MOVING W NEAR 20 KT. WAVE REMAINS EMBEDDED WITHIN A SURGE OF AFRICAN DUST AND IS MOVING OVER EASTERN PORTION OF SOUTH AMERICA. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE S OF 11N TO JUST INLAND OVER GUYANA BETWEEN 57W-60W. TROPICAL WAVE IS ALONG 69W S OF 14N MOVING W NEAR 10 KT. WAVE IS MOSTLY INLAND OVER SOUTH AMERICA AND HAS NO ASSOCIATED SHOWERS/CONVECTION. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N10W 6N20W 7N40W 5N50W 6N56W. SCATTERED MODERATE/STRONG CONVECTION COVERS THE AREA FROM 3N-10N BETWEEN 18W-32W AND ALONG THE COAST OF LIBERIA AFRICA WITHIN 60 NM OF LINE FROM 4N8W TO 6N12W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE FROM 2N-9N BETWEEN 6W-18W INCLUDING THE COASTAL REGIONS OF SW AFRICA AND WITHIN 150 NM N OF THE ITCZ AXIS FROM 32W-37W. DISCUSSION... GULF OF MEXICO... WEAKENING BROAD UPPER RIDGE EXTENDS ALONG THE E COAST OF MEXICO AND OVER THE W GULF ALONG 97W TO INLAND OVER THE US MOVING TOWARD THE MISSISSIPPI VALLEY. UPPER LEVEL TROUGH IN THE W ATLC COVERS THE FAR E GULF E OF 85W WITH DRY STABLE AIR COVERS THE ENTIRE GULF. A SURFACE RIDGE EXTENDS OVER THE GULF INTO THE W ATLC ANCHORED OVER WEST VIRGINIA GIVING THE W GULF RETURN FLOW AND PRODUCING SOME WIDELY ISOLATED LOW LEVEL SHOWERS...THUS MOSTLY FAIR SKIES DOMINATE THE GULF THIS MORNING. CARIBBEAN SEA... THE MAIN FOCUS OF THIS MORNING IS A 1008 MB LOW IN THE SW CARIBBEAN NEAR 11N79W WITH A SURFACE TROUGH EXTENDING NW TO SW OF THE CAYMAN ISLANDS NEAR 18N83W. A SURFACE TROUGH FROM THE W/CENTRAL ATLC EXTENDS ACROSS HAITI TO S OF JAMAICA 17N77W. THIS IS GIVING THE AREA SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90/120 NM OF A LINE FROM JAMAICA NEAR 18N76W ALONG 13N81W TO ALONG THE COAST OF PANAMA TO S NICARAGUA NEAR 9N83W. UPPER RIDGE COVERS THE W CARIBBEAN ANCHORED NEAR 14N72W WHILE AN UPPER RIDGE COVERS THE E CARIBBEAN ANCHORED OVER THE LESSER ANTILLES NEAR 15N60W. THIS IS PRODUCING AN UPPER LEVEL INVERTED TROUGH OVER THE CENTRAL CARIBBEAN ALONG 69W/70W AND GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM HISPANIOLA TO SOUTH AMERICA BETWEEN 70W-76W AND S OF 14N BETWEEN 63W-68W. THE SURFACE LOW IS EXPECTED TO DRIFT WESTWARD AND WEAKEN AS IT MOVES INLAND OVER CENTRAL AMERICA AND NO SIGNIFICANT DEVELOPMENT IS ANTICIPATED. HOWEVER...IT COULD PRODUCE LOCALLY HEAVY RAINFALL OVER PORTIONS OF PANAMA...COSTA RICA...AND NICARAGUA TODAY AND OVER THE NEXT FEW DAYS. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE W ATLC WITH THE UPPER LOW OVER THE CANADIAN MARITIMES AND EXTENDING W INTO THE FAR E GULF OF MEXICO. THE ASSOCIATED COLD FRONT EXTENDS E BERMUDA BUT N OF THE REGION. A POST-FRONTAL SURFACE TROUGH EXTENDS ALONG 32N67W SW TO 28N77W WITH BROKEN TO OVERCAST LOW/MID CLOUDS WITH ISOLATED SHOWERS N OF A LINE FROM 32N64W TO THE FLORIDA COAST NEAR PALM BEACH. A JET STREAM WITH WINDS ESTIMATED TO BE 70 TO 90 KT EXTENDS ALONG THE EASTERN EDGE OF THE UPPER TROUGH FROM NEAR 23N74W TO BEYOND 32N54W. A REMNANT STATIONARY FRONT FROM AN UPPER SYSTEM THAT IS WELL N OF THE REGION EXTENDS INTO THE W/CENTRAL ATLC NEAR 32N48W SW TO 25N58W CONTINUING AS A SURFACE TROUGH ALONG 20N70W THEN ACROSS HAITI INTO THE CARIBBEAN. SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS ARE WITHIN 150 NM OF THE FRONT AND WITHIN 120 NM OF SURFACE TROUGH TO ACROSS HISPANIOLA. AN UPPER HIGH IS OVER THE LESSER ANTILLES NEAR 15N60W EXTENDING AN UPPER RIDGE NE ALONG 23N52W TO BEYOND 32N37W. A WEAKENING UPPER TROUGH IS UNDERCUTTING THE UPPER RIDGE ABOVE EXTENDING FROM 18N44W TO 9N48W. A NARROW UPPER TROUGH IS OVER THE FAR E ATLC N OF 23N E OF 25W TO THE COAST OF W AFRICA WITH NO ASSOCIATED SURFACE FEATURES. ZONAL WESTERLY UPPER FLOW DOMINATES THE REMAINDER OF THE TROPICAL ATLC S OF 18N E OF 40W. BROAD AREA OF AFRICAN DUST COVERS THE TROPICS W OF 30W N OF THE ITCZ AND INTO THE SE CARIBBEAN S OF 15N E OF 63W. THE FIRST VISIBLE SATELLITE IMAGES SHOW THE AREA E OF 30W IS BEGINNING TO CLEAR OF DUST. $$ WALLACE