000 AXNT20 KNHC 280613 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI SEP 28 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 FEATURES... TROPICAL STORM KAREN HAS SHOWN SIGNS OF WEAKENING DURING THE PAST 6 HOURS BUT IS STILL A TROPICAL STORM OVER THE OPEN WATERS OF THE CENTRAL ATLANTIC. AT 28/0300 UTC KAREN WAS NEAR 14.8N 49.5W OR ABOUT 780 NM EAST OF THE WINDWARD ISLANDS...MOVING WEST NORTHWEST NEAR 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WINDS ARE 50 KT WITH GUSTS TO 60 KT. SEE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. STRONG SWLY SHEAR CONTINUES TO HINDER ANY DEVELOPMENT. IN FACT CONVECTION NEAR THE CENTER HAS DIMINISHED SIGNIFICANTLY DURING THE PAST 6 HOURS. A GRADUAL WEAKENING IS FORECAST FOR THE NEXT FEW DAYS. A BAND OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF THE CENTER FROM 11N-17N BETWEEN 43W-47W. HURRICANE LORENZO IS CENTERED NEAR 20.5N 96.5W AT 28/0300 UTC OR OR ABOUT 70 MILES...110 KM...EAST-SOUTHEAST OF TUXPAN MEXICO MOVING WEST AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT GUSTS 85 KT. SEE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT3/ WTNT33 KNHC FOR MORE DETAILS. LORENZO SHOULD MAKE LANDFALL ALONG THE COAST OF MEXICO WITHIN THE NEXT 12 HOURS. LORENZO IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES OVER THE MEXICAN STATE OF VERACRUZ...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 15 INCHES. HURRICANE FORCE WINDS ONLY EXTEND 10-20 NM FROM THE CENTER. MEXICAN RADAR FROM ALVARADO SHOWS A SMALL COMPACT EYE ALONG THE MEXICAN COAST WITH A SMALL AREA OF CONVECTION MOVING WEST. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 19N-22N BETWEEN 95W-98W. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLC ALONG 27W SOUTH OF 19W MOVING W 10-15 KT. THE WAVE SHOWS UP WELL IN LOW LEVEL SATELLITE DERIVED WINDS AND VORTICITY...AND THE UW CIMSS TPW PRODUCTS WITH A GOOD MOISTURE SURGE. SIGNIFICANT DEVELOPMENT OF THIS SYSTEM IS NOT ANTICIPATED FOR THE NEXT 24 HOURS. A CLUSTER OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF THE WAVE AXIS FROM 13N-16N BETWEEN 24W AND 26W. SIMILAR CONVECTION IS W OF THE WAVE AXIS FROM 12N-14N BETWEEN 27N-29N. A TROPICAL WAVE IS OVER THE CARIBBEAN ALONG 74W/75W S OF 22N MOVING W NEAR 10-15 KT. THIS WAVE IS PRODUCING CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION OVER THE SOUTHERN BAHAMAS FROM 20N-24N BETWEEN 72W-75W. CONVECTION ASSOCIATED WITH THIS WAVE IS FORECAST TO SPREAD OVER EASTERN CUBA AND JAMAICA TOMORROW. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 11N25W 9N35W 13N45W 9N60W. BESIDES THE CONVECTION MENTIONED ABOVE WITH T.S. KAREN AND THE TROPICAL WAVE OVER THE E ATLC...ISOLATED MODERATE CONVECTION IS FROM 4N-6N BETWEEN 20W-28W. DISCUSSION... GULF OF MEXICO... HURRICANE LORENZO...WHICH IS ABOUT TO MAKE LANDFALL ON THE MEXICAN COAST IS THE MAIN WEATHER FEATURE ACROSS THE GULF OF MEXICO. THE SLOW MOTION OF LORENZO WILL LIKELY PRODUCE TORRENTIAL RAINFALL ALONG ITS PATH. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. IN THE UPPER LEVELS...AN UPPER HIGH IS OVER LORENZO WITH A RIDGE AXIS EXTENDING NE TO N FLORIDA. DRIER AIR IS FILTERING INTO THE N GULF. BESIDES FOR LORENZO IN THE FAR SW GULF STRONG SUBSIDENCE PREVAILS. EXPECT CONVECTION OVER THE W GULF W OF 95W DURING THE NEXT 24 HOURS MOSTLY DUE TO LORENZO. CARIBBEAN SEA... A TROPICAL WAVE IS MOVING WWD ACROSS THE CENTRAL CARIBBEAN WITH CONVECTION N OF HISPANIOLA. SEE TROPICAL WAVE SECTION. ISOLATED MODERATE CONVECTION IS INLAND OVER N COLOMBIA FROM 5N-10N BETWEEN 72W-77W. SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF W CUBA FROM 19N-20N BETWEEN 77W-79W. TRADE WINDS 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 S OF HISPANIOLA NEAR 15N73W. ANTICYCLONIC FLOW IS BETWEEN 60W-80W. SIGNIFICANT UPPER LEVEL MOISTURE AND BROKEN HIGH CLOUDS COVERS THE ENTIRE CARIBBEAN. EXPECT CONVECTION OVER MOST OF THE CARIBBEAN AND CENTRAL AMERICA W OF 75W. ATLANTIC OCEAN... A 1012 MB LOW IS OVER THE W ATLANTIC NEAR 30N78W. A SURFACE TROUGH EXTENDS SW FROM THE LOW TO S FLORIDA. CLUSTERS OF SCATTERED MODERATE CONVECTION IS E OF THE LOW FROM 27N-32N BETWEEN 70W-76W. A SURFACE TROUGH IS OVER THE CENTRAL ATLANTIC ALONG 28N47W 20N61W. ISOLATED MODERATE CONVECTION IS FROM 22N-26N BETWEEN 50W-60W. A 1023 MB HIGH IS OVER THE E ATLANTIC NEAR 30N30W. IN THE UPPER LEVELS...A RIDGE IS N OF 20N BETWEEN 60W-70W. AN UPPER LEVEL LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 30N56W. WLY FLOW IS OVER THE E ATLANTIC N OF 20N E OF 40W. A LARGE UPPER LEVEL HIGH IS OVER THE TROPICS NEAR 11N35W. ANTICYCLONIC FLOW IS FROM EQ-20N BETWEEN 20W-50W. $$ FORMOSA