000 AXNT20 KNHC 010545 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURE... TROPICAL DEPRESSION SIX IS CENTERED NEAR 12.0N 59.9W AT 01/0300 UTC OR ABOUT 85 MILES SOUTH-SOUTHWEST OF BARBADOS AND ABOUT 120 MILES EAST OF GRENADA MOVING WESTWARD AT 13 KT. MEASURED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS OF 40 KT. 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. DATA FROM THE AIRCRAFT ALONG WITH QUIKSCAT DATA AND SUBSEQUENT SATELLITE INTENSITY ESTIMATES SHOW THAT THE DEPRESSION IS JUST BELOW TROPICAL STORM STRENGTH...AND IT COULD BECOME A TROPICAL STORM AT ANY TIME AS IT MOVES THROUGH THE WINDWARD ISLANDS. MODERATE TO STRONG CONVECTION CONVECTION IS WIDESPREAD ASSOCIATED WITH TD SIX FROM 10-14N BETWEEN 59-62W...MAINLY WEST OF THE CYCLONE. ...TROPICAL WAVES... TROPICAL WAVE IS TILTED ALONG 20N31W 9N36W MOVING W AT ABOUT 12 KT WITH A 1010 MB LOW ALONG THE WAVE NEAR 14N. 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. A CLUSTER OF MODERATE CONVECTION IS WITHIN 150 NM WEST OF THE LOW CENTER. A TROPICAL WAVE IS INTRODUCED ALONG 72W ON THE 00Z SURFACE MAP BASED ON SATELLITE IMAGERY...SFC OBSERVATIONS AND THE SSMI/AMSRE DERIVED TOTAL PRECIPITABLE WATER. THE CIMSS VORTICITY PRODUCT AND THE GFS ALSO INDICATE THE PRESENCE OF THIS FEATURE. THE WAVE COUPLED WITH THE ITCZ IS GENERATING SCATTERED MODERATE CONVECTION OVER WESTERN VENEZUELA AND NORTHERN COLOMBIA...AND IS ALSO HELPING TO INDUCE ISOLATED TO SCATTERED SHOWERS OVER HISPANIOLA. TROPICAL WAVE IS ALONG 81W/82W S OF 21N MOVING W NEAR 10 KT. THE WAVE IS DIFFICULT TO DISCERN FROM SATELLITE IMAGERY THOUGH THERE MAY STILL EXIST A WEAK SURFACE LOW NEAR 12N81W. THE ONLY SIGNIFICANT CONVECTION OCCURRING IN THE VICINITY OF THE WAVE IS OVER LAND IN PANAMA...COSTA RICA AND CUBA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N16W 14N28W 14N32W 9N40W 10N50W 11N58W. IN ADDITION TO SHOWERS/CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...CLUSTERS OF SCATTERED MODERATE CONVECTION ARE ALONG THE COAST OF SW AFRICA FROM 8-15N WEST OF 19W. WIDELY SCATTERED SHOWERS ARE FROM 5N-10N BETWEEN 41W-55W. 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 20N96W AND 18N94W. WIDELY SCATTERED MODERATE CONVECTION IS OCCURRING FROM 20-23N WEST OF 94W. A WEAK 1011 MB LOW IS CENTERED OVER N FLORIDA NEAR 30N84W. A SURFACE TROUGH EXTENDS MAINLY SOUTH TO 26N85W. ISOLATED SHOWERS ARE ASSOCIATED WITH THE TROUGH OVER THE NE CORNER OF THE GULF. A WEAK HIGH PRESSURE CENTER OF 1014 MB IS AT 27N92W. 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 SW PORTION INCLUDING THE BAY OF CAMPECHE...AND OVER THE NE GULF AND FLORIDA...DURING THE NEXT 24 HOURS. CARIBBEAN SEA... ATTENTION REMAINS FOCUSED ON TROPICAL DEPRESSION SIX APPROACHING THE WINDWARD ISLANDS JUST BELOW TROPICAL STORM STRENGTH. WATCHES AND WARNINGS HAVE BEEN ISSUED. IT IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 2 TO 5 INCHES ACROSS THE WINDWARD ISLANDS...WITH MAXIMUM AMOUNTS TO 7 INCHES. 1 TO 3 INCHES OF RAIN ARE EXPECTED ACROSS TRINIDAD AND TOBAGO...COASTAL VENEZUELA AND THE OFFSHORE ISLANDS...AND THE NETHERLAND ANTILLES 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...THOUGH IT MAY BE RESPONSIBLE FOR THE CENTRAL CARIBBEAN CONVECTION. 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 THE TROPICAL WAVE AND CURRENTLY TROPICAL DEPRESSION SIX DURING THE NEXT 24 HOURS. ATLANTIC OCEAN... AS OF 03Z...A SURFACE TROUGH ENTERS THE AREA NEAR 31N72W THEN CONTINUES WSW TO 29N78W. SCATTERED MODERATE CONVECTION IS E OF THE TROUGH AXIS FROM 26N-31N BETWEEN 65W-73W. A DISSIPATING STATIONARY FRONT CLIPS THE CENTRAL ATLANTIC ALONG 31N42W TO 30N50W 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