wdpn31 pgtw 190300 msgid/genadmin/navpacmetoccen Pearl Harbor hi/jtwc// subj/prognostic reasoning for tropical storm 02w warning nr 21// rmks/ 1. For meteorologists. 2. 12 hour summary and analysis. A. The storm has been downgraded to a tropical storm due to rapid weakening over the past 12 hours. Deep convection has waned significantly since the last forecast. Ts 02w continues to track north-northeastward towards southern China. Though the upper level environment continues to provide excellent poleward outflow, increased vertical wind shear, limited interaction with hainan, and low ocean heat content have become primary factors for the observed weakening trend. B. Ts 02w continues to broaden and weaken in the South China Sea, 60 nm from the southern coast of Mainland China. The cirrus-filled eye feature that was present 12 hours ago has since dissolved into a broad central dense overcast with weakened spiral banding wrapping into an elongating low level circulation center (LLCC). Initial intensity estimates are based on satellite intensity estimates from pgtw, knes and rjtd ranging from 45 to 55 knots. Position confidence has also decreased due the broadened nature of the storm. A. The forecast reasoning remains unchanged from the previous forecast. B. Ts 02w will continue to track poleward until it makes landfall to the west of Hong Kong by tau 12. The objective aids are in good agreement with the track forecast. The storm will continue weakening prior to landfall as it encounters a heightened vertical wind shear gradient near 22.0n. Once ashore the topography of southern China will expedite further weakening. Ts 02w will dissipate over land by tau 24.