000 AXNT20 KNHC 170548 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI SEP 17 2010 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 0445 UTC. ...SPECIAL FEATURES... HURRICANE KARL IS CENTERED NEAR 19.7N 94.8W AT 17/0600 UTC OR ABOUT 80 NM ENE OF VERACRUZ MEXICO AND ABOUT 165 NM ESE OF TUXPAN MEXICO MOVING W AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 967 MB. MAXIMUM SUSTAINED WIND SPEED IS 90 KT WITH GUSTS TO 110 KT. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT3/WTNT33 AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS WITHIN 60 NM OF THE CENTER IN ALL QUADRANTS WITH SCATTERED MODERATE/STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM S OF 21N W OF 94W TO INLAND OVER THE S MEXICO. HURRICANE IGOR IS CENTERED NEAR 22.2N 59.2W AT 17/0600 UTC OR ABOUT 325 NM NE OF THE NORTHERN LEEWARD ISLANDS AND ABOUT 675 NM SSE OF BERMUDA MOVING NW AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 935 MB. MAXIMUM SUSTAINED WIND SPEED IS 110 KT WITH GUSTS TO 135 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS WITHIN 6O NM FROM THE CENTER IN THE NE SEMICIRCLE WITH SCATTERED MODERATE/STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 19N-23N BETWEEN 57W-62W. OUTER RAINBANDS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 14N-20N BETWEEN 51W-57W AND FROM 20N-27N BETWEEN 52W-62W. HURRICANE JULIA IS CENTERED NEAR 23.5N 42.9W AT 17/0300 UTC OR ABOUT 1195 NM SW OF THE AZORES MOVING WNW AT 21 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 983 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS TO 85 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE CENTER IN THE NW QUADRANT WITH SCATTERED MODERATE CONVECTION 60 NM OF THE CENTER ELSEWHERE. ...TROPICAL WAVES... TROPICAL WAVE IS OFF THE COAST OF AFRICA ALONG 18W/19W S OF 16N MOVING W 5-10 KT. SATELLITE IMAGERY SHOWS BROAD CYCLONIC TURNING NEAR THE WAVE AXIS NEAR 12N. NO ASSOCIATED SHOWER ACTIVITY/ CONVECTION. ...ITCZ... THE ITCZ/MONSOONAL TROUGH REMAINS ACROSS THE ATLC BASIN FROM 7N21W 11N29W THEN RESUMES NEAR 11N33W 9N40W TO 11N46W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 10N-14N BETWEEN 28W-38W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 7N-13N BETWEEN 22W-26W AND FROM 7N-10N BETWEEN 41W-47W. ...DISCUSSION... GULF OF MEXICO... THE PRIMARY CONCERN FOR THE S GULF OF MEXICO IS HURRICANE KARL THAT COULD BECOME A MAJOR HURRICANE BEFORE MAKING LANDFALL LATER ON FRI OVER MEXICO...SEE SPECIAL FEATURES ABOVE. THE BROAD UPPER RIDGE ASSOCIATED WITH KARL COVERS THE GULF E OF 97W PROVIDING DIFFLUENCE ALOFT TO SUPPORT OUTER RAINBANDS WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVERING MOST OF THE GULF WATERS TO INLAND OVER THE COAST OF LOUISIANA/TEXAS AND TO THE COAST OF THE FLORIDA PENINSULA AND OVER THE FLORIDA KEYS LEAVING THE FLORIDA PANHANDLE CLEAR TONIGHT. A SHORTWAVE UPPER TROUGH IS OVER E TEXAS FROM SAN ANTONIO TO NEAR BROWNSVILLE WITH ACCOMPANYING MODERATE SUBSIDENCE AND DRY AIR AND THUS CLEAR SKIES. CARIBBEAN SEA... ALTHOUGH HURRICANE KARL IS IN THE S GULF OF MEXICO...THE BROAD UPPER RIDGE ASSOCIATED WITH KARL COVERS THE W CARIBBEAN W OF 80W BRINGING HIGH CLOUDS TO THE AREA. AN UPPER RIDGE ANCHORED S OF HURRICANE IGOR IN THE W TROPICAL ATLC IS GIVING THE E CARIBBEAN S TO SW FLOW ALOFT INDUCING AN INVERTED UPPER TROUGH THAT EXTENDS FROM W COLOMBIA NEAR 9N71W TO HAITI NEAR 18N72W. THE N FLOW ALOFT OVER THE SW CARIBBEAN COUPLED WITH THE CONVERGING SURFACE FLOW IS GENERATING ISOLATED SHOWERS/THUNDERSTORMS S OF 13N BETWEEN 73W-82W. STRONG SUBSIDENCE WITH DRY STABLE AIR COVERS THE CARIBBEAN N OF 13N BETWEEN 64W-77W GIVING THE AREA MOSTLY CLEAR SKIES TONIGHT. ATLANTIC OCEAN... HURRICANE IGOR REMAINS A CONCERN FOR THE ATLC WATERS TONIGHT WHILE HURRICANE JULIA BEGINS TO WEAKEN...SEE SPECIAL FEATURES ABOVE. THE UPPER RIDGE ASSOCIATED WITH HURRICANE KARL STILL COVERS THE FAR W ATLC W OF 77W. A SURFACE RIDGE IS BUILDING SW OVER THE W ATLC AND THE N GULF OF MEXICO. OTHERWISE...STRONG SUBSIDENCE AND DRY AIR ALOFT COVERS THE W ATLC FROM 65W-80W GIVING THE AREA FAIR WEATHER TONIGHT. THE UPPER RIDGE ASSOCIATED WITH IGOR COVERS THE CENTRAL ATLC FROM 16N-30N BETWEEN 50W-65W. THE UPPER RIDGE ASSOCIATED JULIA HAS NARROWED OVER THE PAST 24 HOURS EXTENDING MOSTLY N/S. AN E/W UPPER RIDGE HAS ONCE AGAIN DOMINATED THE E TROPICAL ATLC ALONG 20N TO 35W. THE LAST VISIBLE SATELLITE IMAGERY SHOWS DRY SAHARAN AIR AND DUST COVERING THE E ATLC FROM 16N-28N E TO 32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW