000 AXNT20 KNHC 011203 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT SEP 1 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. ...SPECIAL FEATURE... THE SIXTH NAMED STORM OF THE 2007 ATLANTIC SEASON FORMS OVER THE WINDWARD ISLANDS. AT 01/1200 UTC FELIX WAS CENTERED NEAR 12.4N 62.8W OR ABOUT ABOUT 65 NM WEST-NORTHWEST OF GRENADA MOVING WESTWARD AT 16 KT. ON THIS TRACK...FELIX WILL MOVE AWAY FROM THE SOUTHERN WINDWARD ISLANDS LATER THIS MORNING AND WILL BE PASSING NEAR THE ISLANDS OF ARUBA...BONAIRE AND CURACAO LATE TONIGHT OR EARLY SUNDAY MORNING. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WINDS HAVE INCREASED AND ARE NEAR 45 MPH...WITH HIGHER GUSTS. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. RADAR IMAGERY FROM MARTINIQUE INDICATES THAT THE CENTER HAS RECENTLY PASSED OVER GRENADA. THE CLOUD PATTERN OF THE CYCLONE HAS IMPROVED SOMEWHAT OVERNIGHT WITH MODERATE TO STRONG CONVECTION FROM 10N-13N BETWEEN 61W-65W AND THE COLDEST CLOUD TOPS NOW FOCUSED ON A CLUSTER VERY NEAR THE ESTIMATED LOW-LEVEL CENTER LOCATION. ...TROPICAL WAVES... TROPICAL WAVE IS TILTED ALONG 18N32W 8N37W MOVING W AT ABOUT 12 KT WITH A 1010 MB LOW ALONG THE WAVE NEAR 13N. THE WAVE AND LOW ARE EMBEDDED WITHIN A WELL ESTABLISHED MONSOON TROUGH THAT IS PRESENT WITH WEST TO SOUTHWEST WINDS AT THE SURFACE AND 850 MB FROM WEST AFRICA OUT TO 40W BETWEEN 5 AND 15N. MODERATE TO ISOLATED STRONG CONVECTION IS FROM 12N-15N BETWEEN 35W-39W. A TROPICAL WAVE IS 73W SOUTH OF 20N MOVING W 10 TO 15 KT. THE WAVE COUPLED WITH THE COLOMBIAN LOW IS GENERATING CLUSTERS OF SCATTERED MODERATE CONVECTION OVER WESTERN VENEZUELA AND NORTHERN COLOMBIA...AND IS ALSO HELPING TO INDUCE ISOLATED TO SCATTERED SHOWERS OVER HISPANIOLA AND BETWEEN E CUBA AND JAMAICA. TROPICAL WAVE IS ALONG 82W/83W S OF 22N MOVING W 10 TO 15 KT. THE WAVE IS ENHANCING SOME SHOWER ACTIVITY OVER THE ISLE OF YOUTH CUBA AND OVER THE SW CARIBBEAN AND THE CARIBBEAN PLAINS OF NICARAGUA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 13N16W 13N33W 10N40W 9N5W 12N58W. IN ADDITION TO SHOWERS/CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...CLUSTERS OF SCATTERED MODERATE CONVECTION ARE ALONG THE COAST OF SW AFRICA FROM 8-13N EAST OF 24W. WIDELY SCATTERED SHOWERS ARE FROM 5N-10N WEST OF 44W. DISCUSSION... GULF OF MEXICO... WEAK PRESSURE GRADIENT DOMINATES THE AREA WITH MAINLY LIGHT AND VARIABLE WINDS. A WEAK SURFACE TROUGH CONTINUES OVER THE SW GULF VERY CLOSE THE MEXICAN COAST ALONG 24N97W 20N95W AND 18N94W. CONVECTION HAS SLIGHTLY INCREASE OVERNIGHT...MAINLY ON THE NORTHERN END OF THE TROUGH WITH A CLUSTER OF SCATTERED MODERATE CONVECTION WITHIN 35 NM OF 22N97W. A WEAK 1011 MB LOW IS CENTERED OVER N FLORIDA NEAR 30N84W. A SURFACE TROUGH EXTENDS SW FROM THE LOW TO 26N90W. ISOLATED SHOWERS AMD TSTMS ARE RELATED TO THE TROUGH/LOW OVER THE NE CORNER OF THE GULF AND NORTHERN FLORIDA...JUST NORTH OF TAMPA BAY. SIMILAR CONVECTION IS ALSO FOUND OVER THE NW GULF WITH A MOIST ONSHORE FLOW. A WEAK HIGH PRESSURE CENTER OF 1014 MB IS AT 28N92W. ALOFT...A RIDGE IS OVER MEXICO AND THE W GULF W OF 93W. A TROUGH IS OVER THE CENTRAL GULF 88W-93W. AN UPPER LEVEL RIDGE DOMINATES FLORIDA AND THE EASTERN GULF TO 88W. EXPECT CONVECTION OVER MOST OF THE GULF ESPECIALLY OVER THE W PORTION...AND OVER THE NE GULF AND FLORIDA...DURING THE NEXT 24 HOURS. CARIBBEAN SEA... ATTENTION REMAINS FOCUSED ON TROPICAL STORM FELIX MOVING ACROSS THE SOUTHERN WINDWARD ISLANDS. FELIX IS EXPECTED TO PRODUCE ADDITIONAL RAINFALL ACCUMULATIONS OF 1 TO 2 INCHES ACROSS THE WINDWARD ISLANDS WITH STORM TOTAL AMOUNTS OF 7 INCHES POSSIBLE. RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE POSSIBLE OVER COASTAL VENEZUELA AND THE NETHERLANDS ANTILLES ISLANDS OF ARUBA... BONAIRE AND CURACAO. A PAIR OF TROPICAL WAVES ARE MOVING WWD ACROSS THE BASIN. SEE ABOVE. TRADEWINDS ARE MOSTLY 10-15 KT. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER CENTRAL AMERICA W OF 85W. AN UPPER LEVEL LOW IS OVER THE SW CARIBBEAN NEAR 12N81W. A WEAK RIDGE ANCHORED ON A HIGH OVER THE NE CARIBBEAN COVERS THE REMAINDER OF THE AREA. EXPECT THE HIGHEST POTENTIAL FOR CONVECTION TO BE NEAR TROPICAL STORM FELIX AND THE TROPICAL WAVES DURING THE NEXT 24 HOURS. ATLANTIC OCEAN... AS OF 06Z...A SURFACE TROUGH ENTERS THE AREA NEAR 31N70W THEN CONTINUES MAINLY WEST TO 29N77W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF THE TROUGH AXIS N OF 28W BETWEEN 60W-70W. A DISSIPATING STATIONARY FRONT CLIPS THE CENTRAL ATLANTIC ALONG 30N BETWEEN 43W-50W WITH A NARROW LINE OF SHOWERS. A SURFACE RIDGE DOMINATES MOST OF THE FORECAST AREA WEST OF 70W WITH MODERATE TRADE WINDS. ALOFT...AN UPPER LEVEL HIGH IS CENTERED OVER THE WESTERN ATLANTIC NEAR 27N67W. AN UPPER TROUGH OVER THE CENTRAL ATLC N OF AREA SUPPORTS THE ABOVE MENTIONED STATIONARY FRONT. AN UPPER LEVEL RIDGE COVERS THE CENTRAL-EASTERN ATLANTIC E OF 45W ANCHORED ON A HIGH NEAR 22N30W. $$ GR