000 AXNT20 KNHC 092344 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI NOV 09 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 49W S OF 13N MOVING W 20 KT. THIS WAVE APPEARS TO BE MOVING FASTER THAN AN AVERAGE TROPICAL WAVE AND IS ALONG THE LEADING EDGE OF A DENSE AREA OF AFRICA DUST. THE HOVMOLLER DIAGRAM SHOWS THE WWD PROPAGATION OF THE WAVE. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE BEHIND THE WAVE AXIS FROM 5N-9N WEST OF 43W. COMPUTER MODELS HAVE MOISTURE FROM THIS TROPICAL WAVE AFFECTING THE LESSER ANTILLES TOMORROW AND THE UK/US VIRGIN ISLANDS AND PUERTO RICO SUNDAY INTO MONDAY. TROPICAL WAVE IS ALONG 63W S OF 12N MOVING W NEAR 15 KT WITH NO ASSOCIATED DEEP CONVECTION. A WEAK SIGNATURE IS APPARENT ON THE TOTAL PRECIPITABLE WATER IMAGERY. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 5N30W 7N47W 5N55W. BESIDES FOR THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS WITHIN 50 NM S OF THE AXIS BETWEEN 25W-33W. SIMILAR CONVECTION IS WITHIN 60 NM N OF AXIS BETWEEN 37W-42W. DISCUSSION... GULF OF MEXICO... THE ENTIRE GULF IS UNDER THE INFLUENCE OF A 1020 MB HIGH PRES CENTERED OVER SE LOUISIANA. FLOW AROUND THIS FEATURE CONTINUES TO PRODUCE FAIR CONDITIONS AND COLD AIR STRATOCUMULUS ACROSS THE MAJORITY OF THE REGION. RETURN FLOW ON THE WESTERN SIDE OF THIS HIGH IS GENERATING THIN LINES OF SHOWERS OVER THE NW GULF INTO E TEXAS AND SW LOUISIANA. THIN LINES OF DEPICTED AS A SURFACE TROUGH EXTENDING FROM 24N97W TO 20N96W WITH POSSIBLE ISOLATED SHOWERS WITHIN 30 NM OF THE TROUGH. LIGHT TO MODERATE WINDS AROUND THE HIGH WILL PERSIST THROUGHOUT THE WEEKEND. ALOFT... FAIRLY UNIFORM NW FLOW BETWEEN RIDGE OVER MEXICO AND LONG WAVE UPPER TROUGH OVER THE EASTERN U.S./W ATLC IS OVER THE GULF. DRY MID/UPPER AIR DOMINATES THE REGION...AIDING IN THE PLEASANT CONDITIONS. CARIBBEAN SEA... DISORGANIZED SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A SFC TROUGH EXTENDING BETWEEN JAMAICA AND THE W PANAMA/COSTA RICA BORDER REMAIN OVER THE SOUTHWESTERN CARIBBEAN SEA. UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR DEVELOPMENT AT THIS TIME. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE OVER THE SW CARIBBEAN FROM 10N-14N BETWEEN 76W-81W. SIMILAR CONVECTION IS ON THE PACIFIC SIDE ALONG THE COAST OF PANAMA...AND ALSO OVER N COLOMBIA AND WESTERN VENEZUELA. THE COLOMBIAN LOW IS AIDING IN THE FORMATION OF THIS CONVECTIVE ACTIVITY. MODERATE TO STRONG N TO NE WINDS OF 20-25 KT ARE BLOWING ON THE WEST SIDE OF THE SFC TROUGH. AN EARLIER QUIKSCAT PASS ALONG WITH A FEW SHIP OBSERVATIONS CONFIRMED THESE FORCE WINDS. MOST OF THE COMPUTER MODELS SUGGEST THE DEVELOPMENT OF A SFC LOW IN THIS AREA. A BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED BY AN UPPER HIGH INLAND OVER SOUTH AMERICA AND IS ADVECTING TROPICAL MOISTURE OVER THE W CARIBBEAN ENHANCING THE ABOVE MENTIONED ACTIVITY. ANOTHER SFC TROUGH... REMNANTS OF A FRONTAL BOUNDARY IS ENHANCING SOME SHOWER/TSTM ACTIVITY OVER HISPANIOLA AND PUERTO RICO. ATLANTIC OCEAN... A SURFACE TROUGH ENTERS THE REGION NEAR 31N75W AND EXTENDS TO 27N79W. A LINE OF MAINLY LOW CLOUDS WITH ISOLATED SHOWERS IS ASSOCIATED WITH THIS TROUGH. ANOTHER SFC TROUGH...PREVIOUSLY THE TAIL END OF A COLD FRONT...RUNS FROM A 1010 MB LOW LOCATED N OF AREA NEAR 36N55W TO NEAR HISPANIOLA. THIS FEATURE IS PRODUCING A BROAD AREA OF CLOUDINESS WITH EMBEDDED SHOWERS AND TSTMS MAINLY N OF 25N BETWEEN 51W-56W. THIS CONVECTIVE ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE ALONG AN UPPER RIDGE AXIS THAT EXTENDS FROM THE CARIBBEAN ACROSS THE LEEWARD ISLANDS TO BEYOND 32N49W. THE THIRD SURFACE TROUGH EXTENDS FROM A 1007 MB LOW SOUTH OF THE AZORES TO 31N22W THEN SW TO 25N35W. MOST OF THE SHOWER/TSTM ACTIVITY RELATED TO THIS TROUGH IS N OF THE FORECAST AREA. THE LAST FEW VIS SATELLITE PICTURES INDICATE A LARGE AREA OF AFRICAN DUST COVERING THE E ATLC S OF 26N E OF 41W. THE SAHARAN AIR LAYER FROM CIMSS DEPICTS THE WWD PROPAGATION OF THIS SURGE OF DRY/STABLE AIR ON THE HEELS OF A TROPICAL WAVE LOCATED NEAR 49W. AN UPPER LOW IS JUST SOUTH OF THE AZORES NEAR 35N28W WHILE AN UPPER RIDGE COVERS THE REMAINDER OF THE ATLC FORECAST AREA AND THE WEST COAST OF AFRICA. $$ GR