000 AXNT20 KNHC 241038 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN AUG 24 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 FEATURES... A 1009 MB BROAD AND ELONGATED AREA OF LOW PRESSURE PAIRED WITH A TROPICAL WAVE OVER THE EASTERN CARIBBEAN SEA ALONG 69W IS PRODUCING A LARGE BUT DISORGANIZED AREA OF SHOWERS AND THUNDERSTORMS. ATMOSPHERIC CONDITIONS APPEAR CONDUCIVE FOR SOME DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS...AND A TROPICAL DEPRESSION COULD FORM AS IT MOVES GENERALLY WESTWARD AT 10 TO 15 KT OVER THE EASTERN AND CENTRAL CARIBBEAN SEA. THIS WAVE WILL CONTINUE TO PRODUCE SQUALLY WEATHER OVER PORTIONS OF THE SOUTHERN LEEWARD ISLANDS...WINDWARD ISLANDS...AND THE NORTHERN COAST OF VENEZUELA TODAY. ...TROPICAL WAVES... A TROPICAL WAVE IS WEST OF THE CAPE VERDE ISLANDS ALONG 28W/29W MOVING WEST AT 10-15 KT. A QSCAT PASS FROM AROUND 0740 UTC SHOWS CLEARLY A CYCLONIC CIRCULATION ALONG THE WAVE AXIS NEAR 12.5N28.5W. A 1010 MB LOW WAS ANALYZED ON THE 0600 UTC SURFACE MAP IN THAT AREA. A CLUSTER OF MODERATE CONVECTION IS WITHIN 150 NM NW QUADRANT OF THE LOW CENTER. FIRST VIS IMAGERY FOR THE DAY ALSO SHOWS SOME SIGNS OF BANDING. A TROPICAL WAVE IS ALONG 51W/52W S OF 24N. AN INVERTED V-SIGNATURE IS EVIDENT ON SATELLITE IMAGERY. THE LOW PRES PREVIOUSLY ASSOCIATED WITH THIS WAVE HAS WEAKENED...BUT CONVECTION HAS SLIGHTLY INCREASED E OF THE WAVE LINE. SCATTERED MODERATE CONVECTION IS FROM 20N-24N BETWEEN 47W-56W...MORE CONCENTRATED WITHIN 200 NM E OF THE NORTHERN END OF THE WAVE AXIS. UPPER-LEVEL WINDS ARE FORECAST TO GRADUALLY BECOME LESS CONDUCIVE...BUT SOME SLOW DEVELOPMENT OF THIS DISTURBANCE IS STILL POSSIBLE DURING THE NEXT COUPLE OF DAYS AS IT MOVES W-NW OR NW AT 10-15 KT. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 16N16W 13N26W 9N35W 13N50W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 7N-12N EAST OF 21W TO THE COAST OF W AFRICA. A LARGE AREA OF MODERATE TO STRONG CONVECTION IS INLAND OVER W AFRICA APPROACHING THE COAST THROUGH WESTERN MAURITANIA AND N SENEGAL. SCATTERED MODERATE CONVECTION IS FROM 5N-8N BETWEEN 46W-50W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 09Z...THE CENTER OF TROPICAL DEPRESSION FAY WAS LOCATED NEAR LATITUDE 31.6 NORTH...LONGITUDE 88.2 WEST...OR ABOUT 50 NM...88 KM...NORTH OF MOBILE ALABAMA. THE DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR 8 MPH. A GENERAL WESTWARD MOTION WITH LITTLE CHANGE IN FORWARD SPEED IS EXPECTED DURING THE NEXT DAY...BUT FAY COULD BECOME NEARLY STATIONARY ON MONDAY. ON THE FORECAST TRACK...FAY WILL BE MOVING OVER SOUTHERN MISSISSIPPI TODAY AND WILL BE LOCATED OVER EASTERN LOUISIANA ON MONDAY. VERY GRADUAL WEAKENING IS FORECAST DURING THE NEXT COUPLE OF DAYS. CURRENTLY...RAINBANDS ASSOCIATED WITH FAY CONTINUES TO AFFECT THE SE CONUS BETWEEN GEORGIA AND LOUISIANA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OVER THE COASTAL WATERS OF FLORIDA PARTICULARLY ON THE WEST SIDE. AN UPPER-LEVEL HIGH ANCHORED OVER NW MEXICO DOMINATES THE WESTERN HALF OF THE GULF AND IS HELPING TO INDUCE SCATTERED SHOWERS AND ISOLATED TSTMS OVER E MEXICO N OF 20N E OF 100W. A NARROW UPPER LEVEL TROUGH IS ALONG THE CENTRAL GULF WHILE A SECOND UPPER-LEVEL HIGH CENTERED OVER WESTERN CUBA EXTENDS A RIDGE NWD ACROSS THE E GULF AND THE FLORIDA PENINSULA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE NOTED OVER THE N GULF WATERS N OF 26N. THIS ACTIVITY REMAINS ASSOCIATED WITH THE CIRCULATION OF FAY WHICH IS ALSO PRODUCING NW TO W WINDS IN THE 15-20 KT RANGE ACROSS THE NORTHERN GULF WATERS E OF 92W AND N OF 27N. MAINLY LIGHT WINDS ARE SEEN ACROSS THE REMAINDER OF THE AREA. THE CARIBBEAN SEA... CONVECTION HAS INCREASED OVERNIGHT OVER THE EASTERN CARIBBEAN. ALL THIS WEATHER IS ATTRIBUTED TO A LARGE AREA OF LOW PRES AND A TROPICAL A TROPICAL WAVE. SEE SPECIAL FEATURE ABOVE. PRES ARE FALLING NEAR 2 MB OVER THAT AREA. WINDS ARE EXPECTED TO INCREASE TO 15-20 KT OVER THE EASTERN CARIBBEAN TODAY THROUGH MON DUE TO THE PRESENCE OF THE TROPICAL WAVE/LOW. AN UPPER-LEVEL TROUGH FROM THE W ATLC ENTERS THE CARIBBEAN SEA THROUGH HISPANIOLA THEN CONTINUES SW TO N COLOMBIA. UPPER DIFFLUENCE BETWEEN THIS TROUGH AND A RIDGE OVER THE E CARIBBEAN IS SUPPORTING THE DEVELOPMENT OF SHOWERS AND TSTMS OVER THE AREA. THE UPPER-LEVEL HIGH LOCATED OVER W CUBA COVERS MOST OF THE CENTRAL AND WESTERN CARIBBEAN GIVING THE AREA ELY UPPER LEVEL FLOW. THE ATLANTIC OCEAN... THE SUBTROPICAL RIDGE ENVELOPS THE FORECAST AREA PRODUCING MOSTLY EASTERLY SURFACE FLOW OVER THE ATLANTIC OCEAN FROM 23N-32N BETWEEN W AFRICA AND 80W. TIGHT PRES GRADIENT BETWEEN THE SFC HIGH AND LOWER PRES OVER AFRICA IS PRODUCING A SWATH OF MODERATE TO STRONG NELY WINDS BETWEEN THE MADEIRA/CANARY ISLANDS AND THE WEST AFRICAN COAST. IN THE UPPER LEVELS...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE REGION WITH A COUPLE OF UPPER-LEVEL LOWS LOCATED NEAR 34N70W AND OVER THE E ATLC NEAR 28N29W. THE CENTRAL ATLC IS UNDER THE INFLUENCE OF AN UPPER-LEVEL HIGH THAT EXTENDS A RIDGE SOUTH OVER THE N TROPICAL ATLC AND THE E CARIBBEAN. AN AREA OF SHOWERS WITH EMBEDDED TSTMS HAS DEVELOPED OVER THE W ATLC FROM 24N-32N BETWEEN 65W-75W...AND IS ASSOCIATED WITH THE AFOREMENTIONED UPPER-LEVEL LOW THAT HAS A TROUGH ALONG 71W/72W EXTENDING INTO THE CARIBBEAN SEA. $$ GR