JTWC Report PDF - Weather Underground

continuedto weaken. By 260600zthe maximmnsurfacewinds htd drcppedbelow 30 kt (15tis). Oespitethefact that a wsll-definedlowlevel circulationwasstillpresent,the lack of persistentcentralconvectionand the systemsrapidmovementto the wastsouthwestmade furtherdevelcgmentseem unlikely(Figure3-07-2). Aa a consequence,the finalwarningwasissuedat 260600z,with the caveatthat “the systemwill be clcselynmnitoredfor indicationsof possibleregeneration.” That was preciselywhathappen~ ! Almost immediatelyafterJeff was finalled,convectionbeganto redevelopabout the lcwlevelcentersincethe shearinginfluenceof thetroughwas absent.Throughoutthe nightof the 26thJeff regenera~d,and ~ immediatelyalertedIMena AB(WM347931)and other custcmerscn Okinawaof thechange. Weathersatellik reccrmaissan~reveal~ adramaticincreasein centralconvectionwhen warningswere again issuedon Jeff, as a 35 kt (18tis)TropicalStorm, at 270000Z (Figure3-07-3). BecauseJeff was less than 24-hoursfran affectingOkinawa,Kadem AB went to Conditionof ReadinessIII as aprecaution. AS Jeff nearedOkinmm it s1-,passingabout 75 nm south @ Okinawaat 280530Z. Thewarningsverifiedwell. MaX.im sustainedwitis atKsdenaAS were 25 kt (13u#s), with a peak gust to39 kt (20tie.)at 280208Z. Naha (WFX347930)had a~ak gust of 47 kt (24I#s) at 280355Z. Eighteenhoura afterpassingsouth of Okinawa,Jeff attainedtyphocxintensity. BY that tine, the ‘fyphm tndturnd to the west-northwestas it startedto movearctuilthe westernside of the subtropicalridge.Futkr intensificaticnto a peak of 75 kt (39II/s)crmrred as ‘I’y@cmJeff approached,and msde lam3-fallon, the coast of mainlandChina approximately180 nm (333km) south of Shanghai (WI)58367) (Figure3-07-4). Once onshore,surfacefrictionaleffectacauseda rapid decreasein maximumwirds. Thepersistentcentralconvectionbegan to fall apartand, once again,the systemwas finalled,although“movementback off the ccast and regeneraticn in theYellcwSea” remaineda distinctpossibility(Figure3-07-5).Im3eed,Jeff was rot finishedyet. Warningnumber36 was issuedat 0000Zon 1 Augustas meteorologicalsatellitereconnaisaancereportedsignificantlyincreasdconvectionover water. The trackwas H to the ncrth-northeastaround the wssternedge of the subtropicalridge. Acceleraticmwasgradualas Jeff redevel~ mxinwm surfacewinds of50 kt (26u#S) @ 1800zon 1 Atxy.st.Strongsouthwesterlywindsaloft himleredthe system!sattenpttofurtherintensifyarxlachieveverticalaligmwsmtFigwte3-07-2. The ne.mtyconvect-ion~fiee&no-.LevetcL.tcuf@tion o~ Jedd a4 Lt woA @ta.Ltedioh the I@.&Ztie [26050LZZ July NOAA v.i.mdi.n!ugtvy].FigoW2 3-07-3.Zf?ge mxa.tiondLtiV.LAu & imag~).Lt4IUtij duvnaVMSP40