000 AXNT20 KNHC 150001 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 14 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... HURRICANE IGOR IS CENTERED NEAR 8.8N 53.1W AT 14/2100Z OR ABOUT 655 NM E OF THE NORTHERN LEEWARD ISLANDS MOVING WNW AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 933 MB. MAXIMUM SUSTAINED WIND SPEED IS 124 KT WITH GUSTS TO 150 KT. SATELLITE IMAGERY SHOWS IGOR HAS MAINTAINED A WELL-DEFINED EYE AND VERY GOOD CIRRUS OUTFLOW IN ALL DIRECTIONS. NUMEROUS STRONG CONVECTION IS WITHIN 90 NM OF THE CENTER WHILE NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS ELSEWHERE FROM 13N-24N BETWEEN 46W-56W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. HURRICANE JULIA IS CENTERED NEAR 16.7N 30.2W AT 14/2100 UTC OR ABOUT 405 NM WNW OF THE SOUTHERNMOST CAPE VERDE ISLANDS MOVING WNW AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 982 MB. MAXIMUM SUSTAINED WIND SPEED IS 75 KT WITH GUSTS TO 90 KT. ADDITIONAL STRENGTHENING IS POSSIBLE OVER THE NEXT 12-24 HOURS BEFORE JULIA COMES UNDER INCREASED WESTERLY SHEAR THAT WILL IMPACT THE CYCLONE. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS WITHIN 110 NM OF THE CENTER WHILE SCATTERED MODERATE AND ISOLATED STRONG IS ELSEWHERE FROM 13N-20N BETWEEN 27W-32W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. THE CONVECTION ASSOCIATED TO THE BROAD LOW PRESSURE AREA LOCATED IN THE NORTHWESTERN CARIBBEAN SEA HAS BECOME MORE ORGANIZED OVER THE PAST 6 HOURS...AND HAS BEEN UPGRADED TO TROPICAL STORM KARL. THIS SYSTEM IS CENTERED NEAR 18.4N 84.8W AT 15/0000 UTC OR ABOUT 230 MI...370 KM E OF CHETUMAL MEXICO MOVING WNW AT 13 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SCATTERED STRONG CONVECTION IS GENERATED BY THIS SYSTEM AND COVERS A GREAT AREA OF THE WNW CARIBBEAN W OF 80W N OF 11N INCLUDING INLAND PORTIONS OF CENTRAL AMERICA. THE OUTER BANDS EXTEND TO 25N W OF 71W. THEREFORE...LOCALLY HEAVY RAINFALL IS POSSIBLE OVER PORTIONS OF JAMAICA...CUBA...THE CAYMAN ISLANDS...THE YUCATAN PENINSULA... AND BELIZE DURING THE NEXT DAY OR TWO. THESE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES...ESPECIALLY IN AREAS OF MOUNTAINOUS TERRAIN. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. ...ITCZ... A MONSOONAL TROUGH REMAINS ACROSS THE ATLC BASIN BETWEEN HURRICANES IGOR AND JULIA ANALYZED AS A SURFACE TROUGH ALONG 11N31W TO 12N39W TO 17N44W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 2N-11N BETWEEN 7W-30W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL RIDGE OF HIGH PRESSURE COVERS THE GULF WITH UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE NORTH CENTRAL GULF NEAR 29N91W. THIS UPPER FLOW IS PROVIDING A DRY AIRMASS ALOFT ACROSS MUCH OF THE GULF...NOTED ON WATER VAPOR IMAGERY. THIS AIRMASS IS SUPPRESSING DEEP CONVECTION ACROSS THE BASIN. HOWEVER...A WEAK UPPER LEVEL SHORTWAVE IS CIRCULATING CLOSELY EAST TO THE CENTER OF THE UPPER HIGH...GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE EASTERN GULF WATERS N OF 25N E OF 87W. THIS AREA OF CONVECTION IS EXPECTED TO CONTINUE TO MOVE WEST ACROSS THE NORTH CENTRAL GULF OVER THE NEXT 24 HOURS. ALSO...A SURFACE TROUGH IS ANALYZED OVER THE WESTERN BAY OF CAMPECHE ALONG 95W S OF 22N AND IS PROVIDING FOCUS FOR SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE COASTAL WATERS OF MEXICO W OF 93W S OF 23N. THE OUTER BANDS ASSOCIATED WITH TROPICAL STORM KARL ARE BEGINNING TO ENTER THE FAR SE GULF THROUGH THE YUCATAN CHANNEL. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS REGARDING THIS SYSTEM. CARIBBEAN SEA... THE MAIN FEATURE OF CONCERN IS TROPICAL STORM KARL IMPACTING THE WNW CARIBBEAN. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS REGARDING THIS SYSTEM. ELSEWHERE EAST OF 75W...NUMEROUS SHOWERS AND THUNDERSTORMS ARE NOTED ACROSS THE CENTRAL CARIBBEAN FROM 14N TO 18N BETWEEN 65W AND 75W...ASSOCIATED TO THE OUTER BANDS OF CONVECTION GENERATED BY KARL. WATER VAPOR IMAGERY INDICATES THAT MOSTLY DRY AIR ALOFT AND STRONG SUBSIDENCE IS OVER THE ENE CARIBBEAN E OF 65W N OF 16N E OF 70W INCLUDING THE LEEWARD ISLANDS...PROVIDING OVERALL FAIR WEATHER CONDITIONS TO THIS REGION. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES A DEEP LAYER TROUGH COVERING THE NORTHWESTERN ATLC...SUPPORTING A DISSIPATING STATIONARY FRONT THAT EXTENDS ACROSS THE WESTERN AREA OF DISCUSSION ALONG 32N65W 27N72W 25N80W...GENERATING SCATTERED WEAK SHOWERS WITHIN 20 NM EITHER SIDE OF THE FRONT. THIS FRONT IS EXPECTED TO COMPLETELY DISSIPATE IN 24 HOURS. NUMEROUS HEAVY SHOWERS AND THUNDERSTORMS EXTEND N OF HAITI AND CUBA S OF 24N W OF 71W...INCLUDING THE SE BAHAMAS AND TURKS AND CAICOS ISLANDS...ASSOCIATED WITH TROPICAL STORM KARL DISCUSSED ABOVE IN THE SPECIAL FEATURES SECTION. ASIDE HURRICANES IGOR AND JULIA...THE REMAINDER OF THE ATLC N OF 22N IS UNDER THE INFLUENCE OF DRY AND STABLE AIR ALOFT AROUND AN UPPER LEVEL RIDGE SUPPORTING A 1030 MB HIGH LOCATED NORTH OF THE DISCUSSION AREA NEAR 43N29W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA