000 AXNT20 KNHC 091743 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 46W/47W S OF 12N MOVING W 20 KT. THIS WAVE APPEARS TO BE MOVING FASTER THAN AN AVERAGE TROPICAL WAVE AND IS ALONG A LEADING EDGE OF A DENSE AREA OF AFRICA DUST. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE BEHIND THE WAVE AXIS FROM 4N-10N WEST OF 42W. TROPICAL WAVE IS ALONG 62W S OF 12N MOVING W NEAR 15 KT WITH NO ASSOCIATED DEEP CONVECTION. A WEAK SIGNATURE IS APPARENT ON THE PRECIPITABLE WATER IMAGERY. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N9W 4N20W 7N40W 5N55W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 60 NM S OF THE AXIS BETWEEN 12W-15W. SIMILAR CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 180 NM N OF THE ITCZ AXIS FROM 23W-27W. A CLUSTER OF MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 34W-38W. DISCUSSION... GULF OF MEXICO... FLOW AROUND A 1021 MB SURFACE HIGH OVER SOUTHERN MISSISSIPPI CONTINUES TO PRODUCE FAIR CONDITIONS AND COLD AIR STRATOCUMULUS ACROSS THE MAJORITY OF THE GULF. RETURN FLOW AROUND THIS HIGH IS 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...A BROAD UPPER TROUGH CONTINUES TO MOVE ACROSS THE GULF INTO THE W ATLC. CARIBBEAN SEA... A REMNANT SURFACE TROUGH REMAINS OVER THE SW CARIBBEAN EXTENDING FROM S OF JAMAICA NEAR 16N77W TO OVER W PANAMA/COSTA RICA NEAR 9N83W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF THE SURFACE TROUGH. A LARGE CLUSTER OF CONVECTION IS SITUATED SOUTH OF 13N BETWEEN THE SURFACE TROUGH AND A 1008 MB SURFACE LOW OVER COLOMBIA NEAR 10N75W. MODERATE TO STRONG N TO NE WINDS IN THIS AREA WILL DECREASE TO 20 KT LATE TONIGHT. 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 ACTIVITY THERE. REMNANT SHOWERS FROM A DISSIPATED SURFACE TROUGH REMAIN N OF 17N BETWEEN PUERTO RICO AND HISPANIOLA. THE EASTERN CARIBBEAN REMAINS RELATIVELY CLEAR WITH LIGHT TO MODERATE EASTERLY WINDS. ATLANTIC OCEAN... A SURFACE TROUGH...PREVIOUSLY THE TAIL END OF A COLD FRONT...EXTENDS FROM 24N76W WESTWARD TO 24N82W. A WEAKENING FRONTAL BOUNDARY FROM THE NORTH CENTRAL ATLC ENTERS THE REGION NEAR 30N66W AND EXTENDS TO 26N73W. SCATTERED SHOWERS AND THUNDERSTORMS ARE WITHIN 90 NM OF THIS BOUNDARY. FARTHER EAST...A SURFACE TROUGH EXTENDS FROM A 1010 MB LOW NEAR 35N57W SW TO 23N66W. A BROAD AREA OF SCATTERED SHOWERS/THUNDERSTORMS EXTENDS 250 NM AHEAD OF THE SURFACE TROUGH. 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. A WEAK SURFACE LOW IS IN THE CENTRAL ATLC NEAR 17N50W. THIS LOW HAS LITTLE ASSOCIATED CONVECTION. A SURFACE TROUGH EXTENDS FROM A 1007 MB LOW SOUTH OF THE AZORES TO 31N22W THEN SW TO 26N35W. SCATTERED MODERATE CONVECTION EXTENDS 160 NM AHEAD OF THE TROUGH. SATELLITE IMAGERY INDICATES A LARGE REGION OF AFRICAN DUST COVERS THE E ATLC S OF 26N E OF 41W. $$ WADDINGTON