000 AXNT20 KNHC 110526 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 55W/56W S OF 13N MOVING W 15-20 KT. WAVE REMAINS EMBEDDED WITHIN A SURGE OF AFRICAN DUST AND IS MOVING OVER EASTERN PORTION OF SOUTH AMERICA. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 7N-10N BETWEEN 55W-61W. TROPICAL WAVE IS ALONG 68W S OF 14N BASED ON SURFACE OBSERVATIONS 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 7N32W 6N41W 4N52W. SCATTERED MODERATE/STRONG CONVECTION COVERS THE AREA FROM 2N-9N BETWEEN 17W-34W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1N-8N BETWEEN 3W-13W INCLUDING THE COASTAL REGIONS OF SW AFRICA AND WITHIN 120 NM N OF THE ITCZ AXIS FROM 34W-28W. DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE EXTENDING ALONG THE E COAST OF MEXICO AND THE W GULF ALONG 97W TO INLAND OVER THE CENTRAL US. UPPER LEVEL TROUGH IS MOSTLY IN THE W ATLC BUT COVERS THE E GULF E OF 87W. 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 LOW LEVEL ISOLATED SHOWERS...THUS MOSTLY FAIR SKIES DOMINATE THE GULF TONIGHT. CARIBBEAN SEA... THE MAIN FOCUS OF THE NIGHT IS A 1008 MB LOW IN THE SW CARIBBEAN NEAR 11N79W WITH A SURFACE TROUGH EXTENDING NW TO JUST S OF THE CAYMAN ISLANDS NEAR 18N81W. A SURFACE TROUGH FROM THE W/CENTRAL ATLC EXTENDS ACROSS HAITI TO S OF JAMAICA 17N76W. THIS IS GIVING THE AREA SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120 NM OF A LINE FROM ACROSS HISPANIOLA NEAR 19N71W ALONG 15N78W TO THE COAST OF PANAMA AND COSTA RICA NEAR 9N82W. BROAD UPPER RIDGE COVERS THE W CARIBBEAN ANCHORED NEAR 13N75W WHILE AN UPPER RIDGE COVERS THE E CARIBBEAN ANCHORED IN THE W TROPICAL ATLC NEAR 16N60W. THIS IS PRODUCING AN UPPER LEVEL INVERTED TROUGH OVER THE CENTRAL CARIBBEAN ALONG 70W/71W. ALTHOUGH THE SURFACE LOW/TROUGH ARE SHOWING A FEW SIGNS OF ORGANIZATION...NO SIGNIFICANT DEVELOPMENT IS ANTICIPATED BEFORE IT MOVES INLAND OVER CENTRAL AMERICA IN THE NEXT DAY OR TWO. HOWEVER...IT COULD PRODUCE LOCALLY HEAVY RAINFALL OVER PORTIONS OF PANAMA...COSTA RICA...AND NICARAGUA DURING 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 E GULF OF MEXICO. THE ASSOCIATED COLD FRONT EXTENDS ACROSS BERMUDA TO 29N69W. DUE TO THE DRY AIR OVER THE AREA FROM 22N-30N W OF 65W...LITTLE IN THE WAY OF SHOWERS CAN DEVELOP. A SECOND SURGE IN THE FORM OF A SURFACE TROUGH EXTENDS ALONG 32N70W SW TO 28N77W WITH OVERCAST LOW/MID CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH. A JET STREAM WITH WINDS ESTIMATED TO BE 70 TO 100 KT EXTENDS ALONG THE EASTERN EDGE OF THE UPPER TROUGH FROM NEAR 22N73W TO BEYOND 32N54W. A REMNANT COLD FRONT FROM AN UPPER SYSTEM THAT IS WELL N OF THE REGION EXTENDS INTO THE W/CENTRAL ATLC NEAR 32N48W SW TO 24N60W CONTINUING AS A SURFACE TROUGH ALONG 20N70W THEN ACROSS HAITI INTO THE CARIBBEAN. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 180 NM OF THE COLD FRONT WITH SOME SCATTERED SHOWERS S OF 21N TO OVER HISPANIOLA BETWEEN 68W-72W. AN UPPER HIGH IS IN THE W TROPICAL ATLC NEAR 16N60W EXTENDING AN UPPER RIDGE NE ALONG 21N53W TO BEYOND 32N37W. A WEAK UPPER LOW IS UNDERCUTTING THE UPPER RIDGE ABOVE CENTERED NEAR 14N45W. 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 MOST OF THE TROPICS N OF THE ITCZ AND IS SPREADING ACROSS WITH WINDWARD ISLANDS TONIGHT ALTHOUGH IT IS BECOMING LESS DENSE E OF THE CAPE VERDE ISLANDS. $$ WALLACE