000 AXNT20 KNHC 140000 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN MAY 13 2007 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 4N10W 2N25W CROSSING THE EQUATOR AT 45W TO NE BRAZIL NEAR 1S53W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-6N EAST OF 16W. SIMILAR CONVECTION IS JUST W OF THE PRIME MERIDIAN FROM 2N TO THE COAST OF AFRICA. ...DISCUSSION... GULF OF MEXICO... UPPER TROUGH EXTENDS FROM SE LOUISIANA TO CENTRAL FLORIDA INTO THE W ATLC. A JET STREAM BRANCH WITH CORE WINDS OF 70 KT LIES SOUTH OF THIS TROUGH ALONG 23N AND GOES FROM 23N95W THROUGH THE STRAIT OF FLORIDA/NW BAHAMAS TO BEYOND 27N70W. UPPER NW TO W WINDS DOMINATES MOST OF THE GULF. THE ATTENDANT BACK DOOR COLD FRONT IS ENTERING NORTHERN FLORIDA AND WILL MOVE INTO THE NE GULF LATE TONIGHT. MOSAIC DOPPLER RADAR FROM THE SE U.S. SHOWS AN AREA OF SHOWERS WITH EMBEDDED TSTMS OVER N-CENTRAL FLORIDA PROBABLY ASSOCIATED WITH A 1011 MB SFC LOW LOCATED JUST EAST OF TALLAHASSEE NEAR 30N83W ON THE 21Z MAP. ANOTHER AREA OF SIMILAR CONVECTION IS JUST NORTH OF LAKE OCKEECHOBEE. A WEAK 1017 MB SURFACE HIGH IS OVER THE NORTHWEST CORNER OF THE GULF NEAR 28N96W. INFORMATION FROM NESDIS INDICATES THAT SMOKE IS STILL COVERING THE N GULF FROM THE CENTRAL COAST OF TEXAS SE THROUGH THE STRAITS OF FLORIDA INTO THE W ATLC INCLUDING ALL OF FLORIDA AND THE FLORIDA KEYS. WEAK HIGH PRES WILL REMAIN NEARLY STATIONARY OVER THE NW GULF THROUGH MON NIGHT. FAIR WEATHER AND LIGHT WINDS ARE FOUND NEAR THE HIGH. CARIBBEAN SEA... WLY FLOW WITH MODERATE TO STRONG SUBSIDENCE DOMINATES THE MAJORITY OF THE BASIN WITH AN UPPER RIDGE ANCHORED BY AN UPPER HIGH OVER NE VENEZUELA EXTENDING ALONG 10/12N. DIFFLUENCE ASSOCIATED WITH THIS RIDGE AND THE CLOSE PROXIMITY OF THE EPAC ITCZ ARE ENHANCING CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION OVER THE SW CARIBBEAN...WESTERN PANAMA AND COSTA RICA. SIMILAR CONVECTION IS ALSO SEEN NEAR LAKE MARACAIBO. A SFC TROUGH FROM THE ATLC ENTERS THE CARIBBEAN THROUGH EASTERN CUBA CROSSING BETWEEN JAMAICA AND THE CAYMAN ISLANDS. MOST OF THE SHOWER/TSTMS ACTIVITY IS JUST E OF THE TROUGH AXIS AFFECTING E CUBA...JAMAICA AND THE REGIONAL COASTAL WATERS. MODERATE TO FRESH ELY FLOW CONTINUES OVER THE EASTERN AND CENTRAL CARIBBEAN BETWEEN THIS TROUGH AND A RIDGE THAT INVADES THE FAR E CARIBBEAN FROM THE CENTRAL ATLC. ATLANTIC... AS OF 21Z...THE REMNANTS OF SUBTROPICAL STORM ANDREA ARE NEAR 31.5N 70.6W. THIS SYSTEM CONTINUES TO MOVE AWAY FROM THE SE US COAST AT A FASTER FORWARD SPEED... AND IS FORECAST TO MERGE WITH AN APPROACHING COLD FRONT AS IT PASSES NEAR BERMUDA ON MONDAY. THUS...THE POTENTIAL FOR REGENERATION INTO A TROPICAL DEPRESSION NO LONGER EXISTS. AN UPPER TROUGH OVER THE EASTERN SEABOARD IS DIGGING SOUTH OVER THE FAR NW PORTION OF THE AREA. A BROAD UPPER RIDGE COVERS THE REMAINDER OF THE W AND CENTRAL ATLC EXTENDING FROM AN UPPER HIGH OVER SOUTH AMERICA ACROSS THE LESSER ANTILLES TO BEYOND 32N42W. UPPER DIFFLUENCE ASSOCIATED WITH THIS FEATURE IS AIDING IN THE DEVELOPMENT OF SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS N OF 23N BETWEEN 52W-72W. A 1014 MB SFC LOW IS ANALYZED ON THE 18Z MAP NEAR 28N62W. THIS LOW WILL MOVE NEWD DURING THE NEXT 24 HOURS. BROAD SURFACE RIDGE DOMINATES THE ATLC E OF 65W. DRY AIR COVERS MUCH OF THE ATLC ESPECIALLY E OF 60W AND IS NOT PRODUCING ANY SHOWER ACTIVITY. VISIBLE SATELLITE IMAGES SHOW A BROAD AREA OF AFRICA DUST ACROSS THE DISCUSSION REGION STRETCHING FROM THE ITCZ N TO 20N AND E OF 52W WITH THE DENSEST PORTION OBSERVED S OF 13N...THUS LIMITING CONVECTION WITHIN THE ITCZ. $$ GR