000 AXNT20 KNHC 160540 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU SEP 16 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... TROPICAL STORM KARL IS CENTERED NEAR 19.7N 91.2W AT 16/0600 UTC OR ABOUT 45 NM W-SW OF CAMPECHE MEXICO AND ABOUT 355 NM E-SE OF TUXPAN MEXICO MOVING W-NW AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 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 90 NM OF THE CENTER IN THE SW QUADRANT WITH SCATTERED MODERATE/STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 17N-20N E OF 94W TO INLAND OVER THE YUCATAN. KARL HAS MOVED INTO THE BAY OF CAMPECHE AND IS EXPECTED TO STRENGTHEN AND BECOME A HURRICANE BY FRIDAY. HURRICANE IGOR IS CENTERED NEAR 20.2N 56.5W AT 16/0300 UTC OR ABOUT 390 NM E-NE OF THE NORTHERN LEEWARD ISLANDS AND ABOUT 850 NM SE OF BERMUDA MOVING W-NW AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 942 MB. MAXIMUM SUSTAINED WIND SPEED IS 115 KT WITH GUSTS TO 140 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. SCATTERED STRONG CONVECTION IS WITHIN 12O NM FROM THE CENTER IN THE SW QUADRANT WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 16N-24N BETWEEN 51W-59W. HURRICANE JULIA IS CENTERED NEAR 20.2N 34.6W AT 16/0300 UTC OR ABOUT 655 NM W-NW OF THE CAPE VERDE ISLANDS MOVING NW AT 14 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 962 MB. MAXIMUM SUSTAINED WIND SPEED IS 100 KT WITH GUSTS TO 120 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERS THE AREA FROM 19N-22N BETWEEN 31W-37W. JULIA IS BEGINNING TO EXPERIENCE SOUTHERLY SHEAR AS THE CONVECTION IS MOSTLY N OF THE CENTER. ...ITCZ... THE ITCZ/MONSOONAL TROUGH REMAINS ACROSS THE ATLC BASIN BEING DISTORTED SOMEWHAT BY HURRICANES IGOR AND JULIA EXTENDING FROM 9N13W 8N19W 12N27W THEN RESUMES NEAR 10N34W 8N39W TO 10N45W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 7N-12N E OF 30W TO THE COAST OF SW AFRICA. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 5N-11N BETWEEN 33W-45W. ...DISCUSSION... GULF OF MEXICO... THE PRIMARY CONCERN FOR THE S GULF OF MEXICO IS T.S. KARL THAT IS HAS MOVED OFFSHORE IN THE BAY OF CAMPECHE...SEE SPECIAL FEATURES ABOVE. THE BROAD UPPER RIDGE ASSOCIATED WITH T.S. KARL COVERS THE GULF E OF 95W PROVIDING DIFFLUENCE ALOFT TO SUPPORT OUTER RAINBANDS WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 29N BETWEEN THE COAST OF THE FLORIDA PENINSULA TO 94W. AN UPPER TROUGH IS OVER THE FAR W GULF N OF 22N W OF 95W WITH STRONG SUBSIDENCE AND REMARKABLY CLEAR SKIES. CARIBBEAN SEA... ALTHOUGH T.S. KARL HAS MOVED ACROSS THE YUCATAN PENINSULA INTO THE S GULF OF MEXICO...THE BROAD UPPER RIDGE ASSOCIATED WITH T.S. KARL COVERS THE W CARIBBEAN W OF 75W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N TO OVER CUBA BETWEEN 80W-86W WITH ISOLATED CLUSTERS OF SIMILAR ACTIVITY S OF S OF 17N W OF 75W TO OVER CENTRAL AMERICA. AN UPPER TROUGH EXTENDS OVER THE E CARIBBEAN FROM THE W/CENTRAL ATLC THROUGH THE MONA PASSAGE TO THE GULF OF VENEZUELA COVERING THE ARE E OF 74W WITH DRY STABLE AIR AND MOSTLY CLEAR SKIES WITH THE EXCEPTION OF SOME SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 16N TO OVER SW HISPANIOLA BETWEEN 71W-74W. ATLANTIC OCEAN... HURRICANES IGOR AND JULIA ARE THE PRIMARY FOCUS FOR THE ATLC AGAIN TONIGHT. THE UPPER RIDGE ASSOCIATED WITH T.S. KARL IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 25N TO OVER CUBA W OF 78W INTO THE FLORIDA STRAITS. A WEAK SURFACE RIDGE COVERS THE REMAINDER OF THE W ATLC. A NARROW UPPER TROUGH EXTENDS ACROSS BERMUDA INTO THE W/CENTRAL ATLC ALONG 24N67W THROUGH THE MONA PASSAGE INTO THE CARIBBEAN WITH DRY STABLE AIR E OF HURRICANE IGOR TO OVER THE BAHAMA ISLANDS. THE UPPER RIDGES ASSOCIATED WITH IGOR AND JULIA ARE FAIRLY LARGE AND NEARLY UNIFORMED. STRONG SUBSIDENCE/DRY STABLE AIR AND THUS MOSTLY CLEAR SKIES DOMINATE THE AREA BETWEEN IGOR AND JULIA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW