000 AXNT20 KNHC 091047 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... HURRICANE FRED IS CENTERED NEAR 13.2N 31.7W AT 09/0900 UTC OR ABOUT 435 NM WSW OF THE SOUTHERNMOST CAPE VERDE ISLANDS MOVING WNW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 970 MB. MAXIMUM SUSTAINED WIND SPEED IS 90 KT WITH GUSTS TO 110 KT. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 10N-16N BETWEEN 28W-35W. WIDELY SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 7N-17N BETWEEN 26W-35W. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 65W S OF 18N MOVING W NEAR 18 KT. A MAXIMUM IN DEEP LAYER MOISTURE IS NOTED IN THE TOTAL PRECIPITABLE WATER IMAGERY ACROSS THE ERN CARIBBEAN WHICH IS RESULTING IN AN AREA OF WIDELY SCATTERED SHOWERS N OF 16N BETWEEN 63W-68W...INCLUDING THE US/UK VIRGIN ISLANDS...PUERTO RICO AND THE MONA PASSAGE. TROPICAL WAVE IS ALONG 84W S OF 18N MOVING W NEAR 18 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 14N17W 14N27W 8N37W 6N49W 7N59W. BESIDES THE CONVECTION ASSOCIATED WITH HURRICANE FRED... ISOLATED MODERATE CONVECTION IS ALONG THE W AFRICA COAST FROM 11N-17N BETWEEN 16W-20W. POSSIBLE ISOLATED SHOWERS ARE ALSO FROM 2N-7N BETWEEN 36W-50W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED ACROSS SRN MEXICO NEAR 18N100W AND EXTENDS UPPER RIDGING ACROSS MUCH OF THE GULF. HOWEVER...AN UPPER LEVEL TROUGH CLIPS THE NERN FLORIDA PENINSULA N OF 27N. BETWEEN THESE TWO UPPER LEVEL FEATURES...NW FLOW ALOFT DOMINATES AND IS CARRYING MIDDLE TO HIGH CLOUDINESS EWD N OF 25N W OF 88W. THE DOPPLER RADAR MOSAIC IS DETECTING SCATTERED SHOWERS AND A FEW ISOLATED TSTMS ACROSS THE NW GULF N OF 24N W OF 86W. 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 THROUGH 25N90W TO NEAR TUXPAN MEXICO. UPPER LEVEL DIFFLUENCE IN ASSOCIATION WITH THE UPPER LEVEL RIDGE IS GENERATING SCATTERED SHOWERS SW OF A LINE FROM 24N98W TO 18N93W ACROSS THE FAR SW GULF AND WRN BAY OF CAMPECHE. THE UPPER LEVEL TROUGHING ACROSS THE FLORIDA PENINSULA IS SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM THE SW NORTH ATLC NEAR 25N79W TO ACROSS WRN CUBA AND INTO THE NW CARIBBEAN. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH IS GENERATING SCATTERED SHOWERS AND TSTMS S OF 26N E OF 82W...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 24N68W ACROSS HISPANIOLA AND THE CENTRAL CARIBBEAN TO OVER PANAMA. NLY UPPER LEVEL WINDS ARE FOUND W OF 75W AND ARE PROVIDING AN OVERALL SUBSIDENT ATMOSPHERE ACROSS THE NW AND SW 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 25N79W TO 20N83W AND ARE LOCATED FROM 18N-22N BETWEEN 78W-83W. MOSTLY DRY AIR ON SWLY WINDS ALOFT ARE ACROSS THE REMAINDER OF THE CARIBBEAN BASIN E OF 75W. HOWEVER...SCATTERED SHOWERS AND TSTMS ARE S OF 11N OVER THE SW CARIBBEAN DUE TO THE PROXIMITY OF THE ITCZ AXIS ACROSS PANAMA ALONG 8N. MODERATE TO FRESH TRADE WINDS CONTINUE ACROSS THE BASIN IN THE LOW LEVELS...WITH PASSING ISOLATED SHOWERS N OF 16N BETWEEN 63W-68W. THE TROPICAL WAVE ALONG 65W WILL CONTINUE TO ENHANCE THESE SHOWERS ACROSS THE US/UK VIRGIN ISLANDS...PUERTO RICO AND THE MONA PASSAGE 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 WEST PALM BEACH FLORIDA. THIS TROUGH IS SUPPORTED ALOFT BY UPPER LEVEL TROUGHING N OF 26N W OF 73W. ANOTHER SURFACE TROUGH IS ANALYZED FROM NEAR 25N79W ACROSS WRN CUBA AND INTO THE NW CARIBBEAN NEAR 20N83W. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH AND UPPER LEVEL DIFFLUENCE E OF THE UPPER LEVEL TROUGHING ARE GENERATING SCATTERED SHOWERS AND TSTMS OVER A LARGE PORTION OF THE W ATLC N OF 23N W OF 72W. FARTHER TO THE E...AN UPPER LEVEL LOW IS CENTERED NEAR 24N68W AND IS GENERATING AN AREA OF ISOLATED SHOWERS FROM 23N-27N BETWEEN 65W-70W. E OF THIS AREA... A 1014 MB SURFACE LOW IS CENTERED NEAR 20N60W AND IS REMNANT ENERGY FROM THE TROPICAL WAVE MOVING ACROSS THE ERN CARIBBEAN. SCATTERED SHOWERS AND TSTMS ARE FROM 19N-22N BETWEEN 58W-62W. INTO THE CENTRAL ATLC...A 1015 MB LOW IS CENTERED NEAR 31N43W AND EXTENDS A WEAK STATIONARY FRONT SW TO NEAR 28N52W. A PRE-FRONTAL TROUGH IS ANALYZED FROM THE LOW TO 26N47W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE STATIONARY FRONT. S OF THE FRONT...A SURFACE TROUGH IS ANALYZED ALONG 25N40W TO 15N42W. SCATTERED SHOWERS ARE OCCURRING FROM 19N-23N BETWEEN 38W-42W. ACROSS THE TROPICAL ERN ATLC...AN UPPER LEVEL RIDGE IS E OF 40W AND IS ENHANCING THE CONVECTION ASSOCIATED WITH HURRICANE FRED. $$ HUFFMAN