000 AXNT20 KNHC 291027 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT SEP 29 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 FEATURES... KAREN IS HOLDING STEADY UNDER STRONG UPPER LEVEL SOUTHWESTERLY FLOW AS A MINIMAL TROPICAL STORM OVER THE OPEN WATERS OF THE CENTRAL ATLANTIC. AT 29/0900 UTC KAREN IS NEAR 16.6N 52.9W OR ABOUT 590 MILES...950 KM...EAST OF THE LEEWARD ISLANDS... MOVING WEST NORTHWEST NEAR 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. KAREN HAS LITTLE CONVECTION NEAR THE CENTER AND A LOT E OF THE CENTER. A GRADUAL WEAKENING IS FORECAST FOR THE NEXT FEW DAYS DUE TO THE UNFAVORABLE UPPER WIND ENVIRONMENT. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 17N-19N BETWEEN 46W-53W...AND FROM 13N-17N BETWEEN 47W-51W. TROPICAL STORM MELISSA AT 29/0900 UTC IS NEAR 14.1N 27.4W OR ABOUT 260 MILES...420 KM...WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS MOVING WEST NEAR 2 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. THE CLOUD PATTERN HAS REMAINED THE SAME FOR THE PAST 24 HOURS. THE CENTER IS IS ON THE W SIDE OF THE ELLIPTICAL SIZED CONVECTION AREA. THE SYSTEM IS FORECAST TO REMAIN A TROPICAL STORM FOR A FEW DAYS...THEN DISSIPATE TO A REMNANT LOW BY 120 HOURS DUE TO PERSISTENT VERTICAL SHEAR. PRESENTLY SCATTERED MODERATE TO STRONG CONVECTION IS FROM 13N-16N BETWEEN 25W-28W. ...TROPICAL WAVES... A TROPICAL WAVE IS BETWEEN T.S. MELISSA AND T.S. KAREN ALONG 36W SOUTH OF 20W MOVING W 10-15 KT. THE WAVE SHOWS UP IN LOW LEVEL SATELLITE DERIVED WINDS AND VORTICITY...AND THE UW CIMSS TPW PRODUCTS WITH A LOW AMPLITUDE MOISTURE SURGE. WIDELY SCATTERED MODERATE CONVECTION IS FROM 4N-6N BETWEEN 30W-36W. A TROPICAL WAVE IS OVER THE CARIBBEAN ALONG 83W S OF 21N MOVING W NEAR 10-15 KT. SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF NICARAGUA FROM 10N-12N BETWEEN 82W-84W. THE WAVE IS ALSO ENHANCING SCATTERED MODERATE CONVECTION OVER JAMAICA FROM 16N-18N BETWEEN 76W-79W. MOISTURE FROM THIS WAVE WILL CONTINUE TO AFFECT CUBA AND CENTRAL AMERICA TODAY. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 8N18W 12N25W 9N35W 13N50W 10N62W. BESIDES THE CONVECTION MENTIONED ABOVE WITH TROPICAL CYCLONES AND THE TROPICAL WAVE OVER THE EASTERN ATLANTIC... SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALONG THE COAST OF W AFRICA FROM 10N-12N BETWEEN 16W-18W. DISCUSSION... GULF OF MEXICO... A COLD FRONT IS OVER THE NORTHERN GULF WATERS FROM N FLORIDA TO E TEXAS NEAR CORPUS CHRISTI ALONG 30N81W 29N90W 28N96W. THE FRONT IS DELINEATED BY A WIND SHIFT AND SLIGHT THERMAL COOLING. NO SHOWERS OR CONVECTION ARE ALONG THE FRONT. A SURFACE TROUGH EXTENDS N/S OVER THE W GULF OF MEXICO ALONG 26N98W 20N97W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 20N-27N BETWEEN 95W-98W. THE REMAINDER OF THE GULF OF MEXICO HAS LIGHT ELY SURFACE FLOW WITH MOSTLY FAIR WEATHER. IN THE UPPER LEVELS...AN UPPER HIGH WITH SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE W GULF NEAR 23N94W WITH A RIDGE AXIS EXTENDING N TO LOUISIANA. THE BASE OF A TROUGH WITH STRONG SUBSIDENCE IS OVER NE GULF AND N FLORIDA N OF 27N AND E OF 90W. THIS UPPER LEVEL TROUGH IS HOSTING THE FRONTAL SYSTEM MENTIONED ABOVE. EXPECT THE COLD FRONT TO PUSH DOWN TO S FLORIDA DURING THE NEXT 24 HOURS. EXPECT CONVECTION OVER S FLORIDA. ALSO EXPECT ONSHORE FLOW TO PRODUCE CONVECTION ALONG THE TEXAS COAST DURING THE NEXT 24 HOURS. CARIBBEAN SEA... A TROPICAL WAVE IS MOVING WWD ACROSS THE W CARIBBEAN WITH CONVECTION. SEE TROPICAL WAVE SECTION. SCATTERED MODERATE TO STRONG CONVECTION IS INLAND OVER N COLOMBIA FROM 7N-10N BETWEEN 73W-76W. TRADEWINDS REMAIN LIGHT TO MODERATE ACROSS THE BASIN. IN THE UPPER LEVELS...A SMALL UPPER LEVEL LOW IS OVER THE NW CARIBBEAN NEAR 19N83W. AN UPPER LEVEL HIGH IS N OF COLOMBIA NEAR 12N77W. ANTICYCLONIC FLOW IS OVER THE CENTRAL AND EASTERN CARIBBEAN. SIGNIFICANT UPPER LEVEL MOISTURE AND BROKEN HIGH CLOUDS COVERS THIS AREA. EXPECT CONVECTION OVER MOST OF THE CARIBBEAN AND CENTRAL AMERICA W OF 65W DURING THE NEXT 24 HOURS. ATLANTIC OCEAN... A SURFACE TROUGH IS OVER THE W ATLANTIC EXTENDING S TO CENTRAL CUBA ALONG 30N76W 23N79W. CLUSTERS OF ISOLATED MODERATE CONVECTION IS E OF THE TROUGH AXIS FROM 22N-32N BETWEEN 70W-77W. A 1022 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 37N51W. ANOTHER 1019 MB HIGH IS OVER THE E ATLANTIC NEAR 26N24W. IN THE UPPER LEVELS...A TROUGH IS OVER THE W ATLANTIC N OF 25N W OF 75W. A RIDGE IS N OF 20N BETWEEN 70W-75W. A LARGE UPPER LEVEL LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 26N61W. WLY FLOW IS OVER THE E ATLANTIC N OF 20N E OF 40W. A LARGE UPPER LEVEL HIGH IS OVER THE TROPICS NEAR 12N35W. ANTICYCLONIC FLOW IS FROM EQ-20N BETWEEN 20W-50W. $$ FORMOSA