000 AXNT20 KNHC 110003 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI SEP 10 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 2315 UTC. ...SPECIAL FEATURES... TROPICAL STORM IGOR IS CENTERED NEAR 16.7N 33.3W AT 10/2100 UTC OR ABOUT 620 MI...995 KM W OF THE CAPE VERDE ISLANDS MOVING W AT 18 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. PLEASE SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/ WTNT21 KNHC FOR MORE DETAILS. EASTERLY VERTICAL WIND SHEAR HAS DECREASED OVER IGOR AND UPPER LEVEL OUTFLOW HAS INCREASED. WARMER SEA SURFACE TEMPERATURES WILL ALSO GIVE IGOR A BETTER OPPORTUNITY FOR INTENSIFICATION WITH THE POSSIBILITY OF REACHING HURRICANE STRENGTH BY SUNDAY. NUMEROUS STRONG CONVECTION IS FROM 15N-18N BETWEEN 34W-37W. IN ADDITION SCATTERED MODERATE CONVECTION IS FROM MAINLY W OF THE CENTER FROM 14N-19N BETWEEN 33W-38W. A 1009 MB SURFACE LOW IS OVER THE WINDWARD ISLANDS NEAR 13N60W. WIDELY SCATTERED MODERATE CONVECTION COVERS THE AREA FROM 11N-15N BETWEEN 60W-63W. ENVIRONMENTAL CONDITIONS SHOULD BECOME MORE FAVORABLE FOR DEVELOPMENT INTO A TROPICAL CYCLONE OF THE NEXT 48 HRS AS THE SYSTEM MOVES WNW AT 5 KT. ...TROPICAL WAVES... TROPICAL WAVE IS INLAND OVER W AFRICA ALONG 8W FROM 6N-15N MOVING W 10-15 KT. VISIBLE SATELLITE IMAGERY INDICATES LOW-LEVEL CYCLONIC FLOW IS ABOUT THE WAVE AXIS CONCENTRATED NEAR A 1012 MB LOW ALONG THE AXIS NEAR 11N. SCATTERED MODERATE/STRONG CONVECTION IS MAINLY W OF THE AXIS TO THE AFRICAN COASTLINE. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9W S OF 18N MOVING W AT 15 KT. A 1008 MB LOW IS EMBEDDED ON THE WAVE AXIS NEAR 12N9W. WIDELY SCATTERED CONVECTION IS FROM 5N-15N BETWEEN 7W-14W. ...DISCUSSION... GULF OF MEXICO... A 1015 MB HIGH IS CENTERED OVER THE NE GULF OF MEXICO NEAR 28N86W. 5-10 KT ANTICYCLONIC SURFACE WINDS DOMINATES THE GULF. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER S FLORIDA S OF 27N...AND OVER INLAND CUBA W OF 80W. SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS ARE OVER THE FLORIDA KEYS AND THE STRAITS OF FLORIDA. ISOLATED MODERATE CONVECTION IS OVER THE YUCATAN PENINSULA AND THE EASTERN BAY OF CAMPECHE FROM 19N-21N BETWEEN 89W-92W. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER E TEXAS NEAR 31N96W. AN UPPER LEVEL LOW IS CENTERED OVER THE SW GULF NEAR 22N95W. STRONG SUBSIDENCE COVERS MOST OF THE GULF EXCEPT WHERE CONVECTION IS NOTED. EXPECT... LITTLE CHANGE OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A RATHER LAX SURFACE PRESSURE GRADIENT IS OVER THE CARIBBEAN SEA THUS TRADEWINDS ARE MOSTLY 10-15 KT. CONVECTION FROM THE REMNANTS OF GASTON HAS REACHED THE WESTERN CARIBBEAN. A SURFACE TROUGH NOW EXTENDS FROM CENTRAL CUBA TO S OF THE CAYMAN ISLANDS ALONG 80W FROM 12N-22N. ISOLATED MODERATE CONVECTION IS FROM 13N-24N BETWEEN 76W-83W MOVING W. WIDELY SCATTERED MODERATE CONVECTION IS ALSO OVER THE WINDWARD ISLANDS. SEE THE SPECIAL FEATURES SECTION ABOVE. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS OVER THE E CARIBBEAN NEAR 15N63W. AN UPPER LEVEL RIDGE IS OVER THE W CARIBBEAN WITH A COL OVER THE CENTRAL CARIBBEAN. CONSIDERABLE UPPER LEVEL MOISTURE COVERS MOST OF THE AREA. EXPECT...CONVECTION FROM THE REMNANTS OF GASTON AND THE LOW OVER THE WINDWARD ISLANDS TO MOVE W OVER THE NEXT 24 HOURS WITH CONVECTION. ATLANTIC OCEAN... A 1025 MB HIGH IS OVER THE E ATLANTIC NEAR 34N33W PRODUCING FAIR WEATHER. ELSEWHERE...A WEAK 1015 MB LOW IS OVER THE CENTRAL ATLANTIC NEAR 26N45W. A SURFACE TROUGH EXTENDS S TO 13N45W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE TROUGH AXIS. OF NOTE IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE W ATLANTIC W OF 70W. AN UPPER LEVEL TROUGH IS N OF 20N BETWEEN 50W-70W. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE E ATLANTIC NEAR 23N33W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA