000 AXNT20 KNHC 271904 AAA TWDAT TROPICAL WEATHER DISCUSSION...AMD NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU SEP 27 2007 AMENDED TO UPDATE FOR TROPICAL STORM LORENZO 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM KAREN IN THE ATLANTIC OCEAN AT 27/1500 UTC WAS NEAR 13.7N 47.3W OR 800 NM/1480 KM EAST OF THE WINDWARD ISLANDS. KAREN IS MOVING WEST-NORTHWEST 10 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 55 KT WITH GUSTS TO 65 KT. PLEASE READ THE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT2/ WTNT32 KNHC FOR MORE DETAILS. KAREN IS DISORGANIZED BUT IT IS MAINTAINING TROPICAL STORM STRENGTH. KAREN IS CURRENTLY IN AN AREA OF UNFAVORABLE UPPER-LEVEL WINDS...AND SOME FURTHER WEAKENING IS FORECAST DURING THE NEXT 24 HOURS. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 170 NM/315 KM FROM THE CENTER. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 11N TO 14N BETWEEN 44W AND 46W...AND FROM 15N TO 17N BETWEEN 46W AND 48W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION ARE ELSEWHERE TO THE EAST OF KAREN FROM 10N TO 20N BETWEEN 35W AND 47W. TROPICAL DEPRESSION THIRTEEN WAS UPGRADED TO TROPICAL STORM LORENZO AT 27/1800 UTC. THE CENTER OF TROPICAL STORM LORENZO WAS NEAR 20.5N 95.5W...MOVING WEST-SOUTHWEST 3 KT. THIS POSITION ALSO IS ABOUT 113 NM/130 KM EAST-SOUTHEAST OF TUXPAN MEXICO AND ABOUT 113 NM/130 KM SOUTHEAST OF CABO ROJO MEXICO. THE MAXIMUM SUSTAINED WIND SPEEDS WERE 50 KT WITH GUSTS TO 60 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE WAS 1004 MB. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER THE AWIPS/WMO HEADERS MIATCMAT/WTNT23 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT3/ WTNT33 KNHC FOR MORE DETAILS. TROPICAL STORM 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. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN A 60 TO 90 NM RADIUS OF 20N96W...IN A BURST OF DEEP CONVECTIVE PRECIPITATION IN WHICH THE MAXIMUM CLOUD TOP TEMPERATURES NEAR 79 DEGREES CELSIUS AND THE HIGHEST CLOUD TOPS REACHING 52000 FEET. ...TROPICAL WAVES... AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 25W/26W SOUTH OF 18N MOVING WEST 10 TO 15 KT. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 12N TO 13N BETWEEN 24W AND 25W...AND FROM 12N TO 14N BETWEEN 28W AND 30W. ISOLATED MODERATE SHOWERS FROM 16N TO 17N BETWEEN 20W AND 22W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 72W SOUTH OF 21N MOVING WEST 10 TO 15 KT. AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTER IS IN THE CENTRAL CARIBBEAN SEA NEAR 14N73W. ISOLATED MODERATE SHOWERS ARE BETWEEN 67W AND 73W IN UPPER LEVEL DIFFLUENT FLOW THAT IS BETWEEN AN ATLANTIC OCEAN-TO-CARIBBEAN SEA TROUGH AND THE ANTICYCLONIC FLOW AROUND THE 14N73W CENTER. ...THE ITCZ... 10N12W 10N22W 10N27W 9N34W 11N41W 11N49W 9N54W 8N60W. ISOLATED MODERATE SHOWERS FROM 4N TO 8N BETWEEN 10W AND 20W. A FEW CELLS OF SHOWERS ARE FROM 6N TO 8N BETWEEN 23W AND 26W...AND FROM 5N TO 10N BETWEEN 34W AND 37W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE ALONG THE GUYANA COAST FROM 6N TO 8N BETWEEN 57W AND 59W. ISOLATED MODERATE SHOWERS ARE WITHIN 30 TO 45 NM ON EITHER SIDE OF 7N50W 9N54W 11N60W. DISCUSSION... THE REST OF THE GULF OF MEXICO AWAY FROM T.S. LORENZO... A 1013 MB LOW PRESSURE CENTER HAS FORMED IN THE ATLANTIC OCEAN AT 27/1200 UTC ABOUT 80 NM EAST OF MELBOURNE FLORIDA. THIS LOW CENTER IS ALONG A 32N78W 28N79W 25N80W 23N83W-IN-CUBA TROUGH. A SURFACE TROUGH IS IN THE WATERS OF THE WESTERN ATLANTIC OCEAN...EXTENDING FROM A 1013 MB SURFACE LOW PRESSURE CENTER ABOUT 80 NM EAST OF MELBOURNE FLORIDA TO CUBA. ALL THE PRECIPITATION IS IN THE ATLANTIC OCEAN. MIDDLE TO UPPER LEVEL DRY AIR COVERS THE GULF OF MEXICO WATERS AWAY FROM THE TROPICAL STORM IN THE SOUTHWESTERN CORNER OF THE AREA. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS A LARGE MAJORITY OF THE AREA...EXCEPT FOR A MIDDLE TO UPPER LEVEL TROUGH FROM MIAMI FLORIDA TO THE FLORIDA STRAITS...TO CUBA...AND INTO THE NORTHWESTERN CARIBBEAN SEA NEAR 18N80W...ABOUT 90 NM WEST OF JAMAICA. THE CARIBBEAN SEA... UPPER LEVEL ANTICYCLONIC CIRCULATION FLOW COVERS THE NORTHWESTERN CORNER OF THE AREA...ANTICYCLONIC FLOW AROUND THE PERIPHERY OF T.S. LORENZO. A NARROW TROUGH CUTS INTO THE AREA FROM WESTERN CUBA TO AN AREA ABOUT 90 NM WEST OF JAMAICA. UPPER LEVEL ANTICYCLONIC FLOW COVERS THE REST OF THE CARIBBEAN SEA...AROUND AN UPPER LEVEL CYCLONIC CIRCULATION CENTER NEAR 14N73W. THE ATLANTIC OCEAN... AN UPPER LEVEL RIDGE ON TOP OF A TROUGH IS THE PATTERN WEST OF 65W IN THE ATLANTIC OCEAN THE TROUGH IS PART OF THE SYSTEM CONNECTED TO THE MELBOURNE FLORIDA SURFACE LOW PRESSURE CENTER AND THE CLOUDS AND SHOWERS FROM THE NORTHERN BAHAMAS BEYOND 32N BETWEEN 74W AND 79W. MIDDLE TO UPPER LEVEL DRY AIR HAS MOVED OVER FLORIDA...PUSHING ALL THE CLOUDS AND PRECIPITATION AWAY FROM FLORIDA AND PUTTING IT IN ATLANTIC OCEAN. A MIDDLE TO UPPER LEVEL TROUGH GOES FROM ONE CYCLONIC CIRCULATION CENTER NEAR 32N47W TO 31N55W 19N57W 16N61W IN THE EASTERN CARIBBEAN SEA. A COLD FRONT PASSES THROUGH 32N37W TO 28N46W...DISSIPATING AT 28N45W AND CONTINUING TO 26N57W AND 30N64W. THE SOUTHERNMOST POINT OF THE MIDDLE TO UPPER LEVEL TROUGH IS NORTH OF THE AREA. THE 32N47W 16N61W TROUGH HAS OVERTAKEN THE AREA OF THE COLD FRONT. A 1026 MB HIGH PRESSURE CENTER IS NEAR 34N56W. ANTICYCLONIC FLOW IS NORTH OF THE SURFACE HIGH PRESSURE CENTER. AN UPPER LEVEL RIDGE IS ALONG 24N38W 19N39W 10N39W. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION CENTER NEAR 32N15W PASSING OVER THE CANARY ISLANDS...AND SETTLING NEAR 20N21W. $$ MT