000 AXNT20 KNHC 161112 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURES... TROPICAL STORM KARL IS CENTERED NEAR 19.8N 91.6W AT 16/0900 UTC OR ABOUT 60 NM W OF CAMPECHE MEXICO AND ABOUT 335 NM E OF TUXPAN MEXICO MOVING W-NW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 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 ALONG THE COAST OF MEXICO IN THE E BAY OF CAMPECHE S OF 20N E OF 93W. WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM S OF 21N E OF 96W TO INLAND OVER THE YUCATAN AND S MEXICO. HURRICANE IGOR IS CENTERED NEAR 20.5N 56.8W AT 16/0900 UTC OR ABOUT 380 NM E-NE OF THE NORTHERN LEEWARD ISLANDS AND ABOUT 830 NM S-SE OF BERMUDA MOVING W-NW AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 929 MB. MAXIMUM SUSTAINED WIND SPEED IS 125 KT WITH GUSTS TO 155 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. SCATTERED STRONG CONVECTION IS WITHIN 6O NM FROM THE CENTER IN ALL QUADRANTS WITH SCATTERED MODERATE/STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 16N-23N BETWEEN 52W-60W. HURRICANE JULIA IS CENTERED NEAR 21.2N 36.2W AT 16/0900 UTC OR ABOUT 760 NM W-NW OF THE CAPE VERDE ISLANDS MOVING NW AT 16 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 970 MB. MAXIMUM SUSTAINED WIND SPEED IS 90 KT WITH GUSTS TO 110 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60/75 NM OF LINE FROM 21N37W TO 24N36W. SATELLITE PRESENTATION OF JULIA HAS CONTINUED TO DETERIORATE OVER THE PAST FEW HOURS WITH MOST OF THE DEEP CONVECTION DISPLACED TO THE NORTH OF THE CENTER. ...ITCZ... THE ITCZ/MONSOONAL TROUGH REMAINS ACROSS THE ATLC BASIN BEING DISTORTED SOMEWHAT BY HURRICANES IGOR AND JULIA EXTENDING FROM 10N14W 9N19W 12N22W THEN RESUMES NEAR 11N36W 10N42W TO 12N50W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 60/75 NM OF LINE FROM 12N19W TO 10N26W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 6N-12N BETWEEN 27W-40W. ...DISCUSSION... GULF OF MEXICO... THE PRIMARY CONCERN FOR THE S GULF OF MEXICO IS THAT T.S. KARL COULD BECOME A HURRICANE ON FRI BEFORE MAKING LANDFALL OVER MEXICO...SEE SPECIAL FEATURES ABOVE. THE BROAD UPPER RIDGE ASSOCIATED WITH T.S. KARL COVERS THE GULF E OF 97W PROVIDING DIFFLUENCE ALOFT TO SUPPORT OUTER RAINBANDS WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 30N BETWEEN THE COAST OF THE FLORIDA PENINSULA AND 95W INCLUDING THE FLORIDA KEYS. A NARROW SWATH OF STRONG SUBSIDENCE AND DRY AIR IS OVER THE FAR W GULF N OF 22N W OF 96W AND THUS REMARKABLY CLEAR SKIES THERE THIS MORNING. CARIBBEAN SEA... ALTHOUGH T.S. KARL REMAINS IN THE GULF OF MEXICO...THE BROAD UPPER RIDGE ASSOCIATED WITH T.S. KARL COVERS THE W CARIBBEAN N OF 11N W OF 75W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 11N W OF 75W TO OVER CUBA AND 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 AREA E OF 75W WITH DRY STABLE AIR AND MOSTLY CLEAR SKIES WITH THE EXCEPTION OF SOME SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 16N TO OVER SW HAITI BETWEEN 72W-74W AND FROM 12N-14N BETWEEN 67W-71W. THE ITCZ/MONSOONAL TROUGH CROSSES COLOMBIA AND PANAMA GENERATING SCATTERED SHOWERS/THUNDERSTORMS S OF 11N BETWEEN 75W-79W AND WITHIN 45 NM ALONG THE REMAINDER OF THE COAST OF PANAMA. HIGH CLOUDS WITH POSSIBLE ISOLATED SHOWERS MOVING ACROSS THE LEEWARD/VIRGIN ISLANDS IN THE OUTER RAINBANDS OF HURRICANE IGOR. ATLANTIC OCEAN... HURRICANES IGOR AND JULIA ARE THE PRIMARY FOCUS FOR THE ATLC AGAIN THIS MORNING. THE UPPER RIDGE ASSOCIATED WITH T.S. KARL IS MOVING OUT OF THE W ATLC BUT CONTINUES TO PROVIDE DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 26N TO OVER CUBA W OF 79W INTO THE FLORIDA STRAITS. A WEAK SURFACE RIDGE COVERS THE REMAINDER OF THE W ATLC. A NARROW UPPER TROUGH EXTENDS INTO THE W/CENTRAL ATLC THROUGH 32N63W ALONG 25N67W THROUGH THE MONA PASSAGE INTO THE CARIBBEAN WITH DRY AIR E OF HURRICANE IGOR TO OVER THE BAHAMA ISLANDS. THE UPPER RIDGE ASSOCIATED WITH IGOR CONTINUES TO BE LARGE A RATHER UNIFORM. HURRICANE JULIA IS UNDER SOUTHERLY SHEAR DISRUPTING THE UPPER RIDGE WITH MOST OF THE OUTFLOW TO THE N. STRONG SUBSIDENCE/DRY STABLE AIR AND THUS MOSTLY CLEAR SKIES CONTINUES TO DOMINATE THE AREA BETWEEN IGOR AND JULIA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW