000 AXNT20 KNHC 181803 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT SEP 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... HURRICANE IGOR IS CENTERED NEAR 26.6N 64.1W AT 18/1800 UTC OR ABOUT 400 NM S OF BERMUDA MOVING NW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 945 MB. MAXIMUM SUSTAINED WIND SPEED IS 95 KT WITH GUSTS TO 115 KT. IGOR REMAINS LARGE AND OUTER RAINBANDS ARE EXPECTED TO BEGIN IMPACTING BERMUDA DURING THE NEXT 12-18 HRS. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS FROM 24N-28N BETWEEN 62W-65W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 22N-29N BETWEEN 61W-67W. TROPICAL STORM JULIA IS CENTERED NEAR 28.9N 51.0W AT 18/1500 UTC OR ABOUT 1515 NM WSW OF THE AZORES MOVING NW AT 16 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. WATER VAPOR IMAGERY AND SATELLITE DERIVED WINDS INDICATE THAT THE UPPER LEVEL OUTFLOW OF IGOR IS SHEARING JULIA RESULTING IN THE WEAKENING TO TROPICAL STORM FORCE. FURTHER WEAKENING IS EXPECTED OVER THE NEXT SEVERAL DAYS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS FROM 26N-29N BETWEEN 49W-51W WITH SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 25N-30N BETWEEN 47W-52W. ...TROPICAL WAVES OR TROPICAL LOWS... 1008 MB LOW IS SW OF THE CAPE VERDE ISLANDS NEAR 13N27W MOVING W NEAR 15 KT. TOTAL PRECIPITABLE WATER IMAGERY INDICATES AN AREA OF MAXIMUM MOISTURE SURROUNDING THE LOW. WIDELY SCATTERED MODERATE CONVECTION IS NW OF THE CENTER FROM 12N-17N BETWEEN 25W-31W. ...ITCZ... THE ITCZ AXIS HAS MAINLY BROKEN DOWN DUE TO THE LARGE SCALE WIND FIELD FROM IGOR AND JULIA. ONLY A PORTION REMAINS ALONG 10N38W 10N48W. WIDELY SCATTERED MODERATE CONVECTION IS OFF THE COAST OF SOUTH AMERICA FROM 4N-9N BETWEEN 45W-51W. FURTHER W NEAR THE WINDWARD ISLANDS...ISOLATED MODERATE CONVECTION IS FROM 7N-14N BETWEEN 56W-60W EMBEDDED IN MOISTURE BEING DRAWN NWD BEHIND IGOR. ELSEWHERE...SCATTERED MODERATE CONVECTION IS OFF THE COAST OF WEST AFRICA FROM 4N-9N BETWEEN 10W-17W. ...DISCUSSION... GULF OF MEXICO... A 1008 MB LOW...THE REMNANTS OF HURRICANE KARL...IS INLAND OVER S MEXICO NEAR 18N98W. MOST ALL CONVECTION HAS DISSIPATED NEAR THE LOW CENTER. THE W GULF OF MEXICO HOWEVER STILL HAS SCATTERED MODERATE TO NUMEROUS STRONG CONVECTION FURTHER N FROM 20N-30N BETWEEN 92W-99W. THE REMAINDER OF THE GULF AND FLORIDA HAS MOSTLY FAIR WEATHER. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER THE CENTRAL GULF NEAR 26N90W. CONSIDERABLE UPPER LEVEL MOISTURE COVERS THE GULF W OF 85W. EXPECT... CONTINUED CONVECTION OVER S TEXAS AND THE W GULF OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A BROAD AREA OF UPPER LEVEL MOISTURE COVERS THE NE CARIBBEAN E OF 70W DUE TO HURRICANE IGOR. SCATTERED SHOWERS ARE OVER THE LEEWARD ISLANDS AND PUERTO RICO N OF 16N AS NOTED BY RADAR. WIDELY SCATTERED MODERATE CONVECTION IS OVER THE WINDWARD ISLANDS FROM 11N-15N BETWEEN 60W-64W. ELSEWHERE... SCATTERED MODERATE CONVECTION IS OVER N COLOMBIA AND THE SW CARIBBEAN FROM 10N-12N BETWEEN 70W-83W. ELSEWHERE...SCATTERED SHOWERS ARE IN THE VICINITY OF THE CAYMAN ISLANDS FROM 18N-21N BETWEEN 80W-83W. WEAK 10-15 KT SURFACE WINDS COVERS MOST OF THE CARIBBEAN. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED OVER THE SW CARIBBEAN NEAR 14N83W. STRONG SUBSIDENCE COVERS THE NW CARIBBEAN. AN UPPER LEVEL HIGH IS CENTERED OVER THE WINDWARD ISLANDS NEAR 13N62W. CONSIDERABLE UPPER LEVEL MOISTURE IS OVER THE E CARIBBEAN E OF 70W. EXPECT...CONTINUED SHOWERS AND CONVECTION OVER THE E CARIBBEAN E OF 70W AND OVER THE S CARIBBEAN S OF 15N OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... HURRICANE IGOR...T.S. JULIA...TOGETHER WITH A TROPICAL LOW ARE THE PRIMARY SURFACE FEATURES OVER THE ATLANTIC. IGOR POSES A THREAT TO BERMUDA. SEE ABOVE. THE IGOR EYEWALL IS NOW APPROACHING BUOY 41049 WHERE TROPICAL STORM FORCE WINDS AND 35 FT SEAS ARE BEING REPORTED. OF INTEREST... SATELLITE IMAGERY SHOWS THE UPPER OUTFLOW OF IGOR IS SHEARING JULIA. VISIBLE IMAGERY ALSO SHOWS A LARGE AREA OF DUST OVER THE E ATLANTIC FROM 15N-25N E OF 40W TO W AFRICA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MRF/SMM