000 AXNT20 KNHC 090550 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED SEP 09 2009 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... HURRICANE FRED IS CENTERED NEAR 12.6N 30.6W AT 09/0300 UTC OR ABOUT 385 NM WSW OF THE SOUTHERNMOST CAPE VERDE ISLANDS MOVING WNW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10N-15N BETWEEN 28W-34W. WIDELY SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 7N-15N BETWEEN 26W-34W. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 64W S OF 18N MOVING W NEAR 18 KT. A MAXIMUM IN DEEP LAYER MOISTURE IS NOTED IN THE TOTAL PRECIPITABLE WATER IMAGERY N OF 14N ACROSS THE NE CARIBBEAN WHICH IS LEADING TO AN INCREASED AREA OF WIDELY SCATTERED SHOWERS N OF 15N BETWEEN 60W-67W...INCLUDING PORTIONS OF THE LEEWARD ISLANDS...US/UK VIRGIN ISLANDS...AND PUERTO RICO. TROPICAL WAVE IS ALONG 82W S OF 19N MOVING W NEAR 15 KT. THIS WAVE REMAINS ILL-DEFINED ACROSS THE WRN CARIBBEAN AND MODERATELY DRY AIR ON NLY FLOW ALOFT IS NOTED IN THE UPPER LEVELS. NO DEEP CONVECTION ACCOMPANIES THIS WAVE. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 17N17W 15N27W 10N34W 7N45W 9N61W. BESIDES THE CONVECTION ASSOCIATED WITH HURRICANE FRED... SCATTERED SHOWERS ARE ALONG THE W AFRICA COAST FROM 7N-18N BETWEEN 12W-19W. POSSIBLE ISOLATED SHOWERS ARE ALSO FROM 3N-7N BETWEEN 24W-49W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED ACROSS SRN MEXICO NEAR 18N99W AND EXTENDS UPPER RIDGING ACROSS MUCH OF THE GULF. HOWEVER...AN UPPER LEVEL TROUGH CLIPS THE FAR NE GULF AND NRN FLORIDA PENINSULA N OF 27N. BETWEEN THESE TWO UPPER LEVEL FEATURES...WNW FLOW ALOFT DOMINATES AND IS CARRYING MIDDLE TO HIGH CLOUDINESS EWD N OF 25N W OF 88W WITH A FEW POSSIBLE EMBEDDED ISOLATED SHOWERS. THE LACK OF ANY SIGNIFICANT SURFACE FEATURES AND AN OVERALL WEAK PRESSURE GRADIENT IS PROVIDING THE GULF WITH GENERALLY LIGHT WINDS CIRCULATING AROUND A SURFACE RIDGE THAT EXTENDS FROM THE SE CONUS TO NEAR TUXPAN MEXICO. UPPER LEVEL DIFFLUENCE IN ASSOCIATION WITH THE UPPER LEVEL RIDGE IS GENERATING SCATTERED SHOWERS ACROSS THE WRN BAY OF CAMPECHE S OF 22N W OF 95W...INCLUDING PORTIONS OF INTERIOR SRN MEXICO. THE UPPER LEVEL TROUGHING ACROSS THE FLORIDA PENINSULA IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS S OF 26N E OF 83W... INCLUDING PORTIONS OF THE FLORIDA KEYS AND STRAITS OF FLORIDA. CARIBBEAN SEA... AN UPPER LEVEL TROUGH DIPS SW FROM A SW NORTH ATLC UPPER LOW CENTERED NEAR 23N69W ACROSS HISPANIOLA AND THE CENTRAL CARIBBEAN TO THE SW CARIBBEAN AND OVER PANAMA. NLY UPPER LEVEL WINDS ARE FOUND W OF 77W AND ARE PROVIDING AN OVERALL SUBSIDENT ATMOSPHERE ACROSS THE NW CARIBBEAN AND PORTIONS OF CENTRAL AMERICA. HOWEVER...SCATTERED SHOWERS AND TSTMS HAVE PERSISTED S OF CUBA DUE TO THE PRESENCE OF A SURFACE TROUGH ANALYZED FROM 25N78W TO 20N81W AND ARE LOCATED FROM 17N-22N BETWEEN 77W-83W. MOSTLY DRY AIR ON SWLY WINDS ALOFT ARE ACROSS THE REMAINDER OF THE CARIBBEAN BASIN E OF 77W. A FEW ISOLATED SHOWERS AND TSTMS ARE S OF 10N OVER THE SW CARIBBEAN DUE TO THE PROXIMITY OF THE ITCZ AXIS ALONG 8N. MODERATE TO FRESH TRADE WINDS CONTINUE ACROSS THE BASIN IN THE LOW LEVELS...WITH PASSING ISOLATED SHOWERS N OF 14N E OF 72W. THE TROPICAL WAVE ALONG 64W WILL CONTINUE TO ENHANCE THESE SHOWERS ACROSS THE NRN LEEWARD ISLANDS...US/UK VIRGIN ISLANDS AND PUERTO RICO OVER THE NEXT 12-24 HOURS. ATLANTIC OCEAN... A SURFACE TROUGH ENTERS THE DISCUSSION AREA NEAR 32N74W AND EXTENDS SSW OVER THE WRN TIP OF GRAND BAHAMA ISLAND TO NEAR MIAMI FLORIDA. THIS TROUGH IS SUPPORTED ALOFT BY UPPER LEVEL TROUGHING N OF 27N W OF 75W. ANOTHER SURFACE TROUGH IS ANALYZED FROM ANDROS ISLAND IN THE BAHAMAS NEAR 25N78W ACROSS CENTRAL CUBA AND INTO THE NW CARIBBEAN NEAR 20N81W. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH AND UPPER LEVEL DIFFLUENCE E OF THE UPPER LEVEL TROUGHING ARE GENERATING SCATTERED SHOWERS AND A FEW ISOLATED TSTMS OVER A LARGE PORTION OF THE W ATLC N OF 22N W OF 72W. FARTHER TO THE E...AN UPPER LEVEL LOW IS CENTERED NEAR 23N69W AND IS GENERATING AN AREA OF SCATTERED SHOWERS FROM 19N-26N BETWEEN 62W-69W. EAST OF THIS AREA A 1013 MB SURFACE LOW IS CENTERED NEAR 20N59W AND IS REMNANT ENERGY FROM THE TROPICAL WAVE MOVING ACROSS THE ERN CARIBBEAN. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE CENTER OF THE LOW IN THE ERN SEMICIRCLE. INTO THE CENTRAL ATLC...A DISSIPATING COLD FRONT DIPS INTO THE DISCUSSION AREA NEAR 31N39W AND EXTENDS WSW TO 29N48W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT. S OF THE FRONT...A SURFACE TROUGH IS ANALYZED ALONG 24N40W TO 16N42W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE FROM 21N-25N BETWEEN 36W-41W. ACROSS THE TROPICAL ERN ATLC...AN UPPER LEVEL RIDGE IS E OF 40W AND IS ENHANCING THE CONVECTION ASSOCIATED WITH HURRICANE FRED. $$ HUFFMAN