msgid/genadmin/navpacmetoccen Pearl Harbor hi/jtwc//
subj/prognostic reasoning for typhoon 05w warning nr15//
rmks/
1. For meteorologists.
2. 12 hour summary and analysis.
   A. Typhoon (TY) 05w (Usagi) has further intensified to 120 kts, 
aided by the dual poleward and equatorward outflow channels. The
system continues to track northwestward on the southwestern
periphery of the subtropical ridge (str) anchored east of Japan.
Analysis of water vapor imagery indicates the upper level trough 
which was over the kanto plain yesterday has pulled out. However, 
synoptic analysis at 500 mb shows a break remains between the str 
east of Japan and a Second Ridge west of Okinawa. 
   B. Typhoon (TY) 05w (Usagi) is located approximately 250 nm
west of iwo to. The system has tracked northwestward
at 12 knots over the past 06 hours. The current intensity of 120 kts
is based on Dvorak estimates of 6.5/6.5 by pgtw and 6.0/6.0 by rjtd.
3. Forecast reasoning.   
   A. The forecast reasoning for TY 05w has not changed.
   B. TY 05w will continue to track northwest under the influence
of the str to its east, making landfall over Kyushu near tau 36. The 
available objective aids have collectively shifted the track slightly 
back to the east over the past two warning cycles, as the models are 
indicating the str will not build as far west as in previous runs. 
The future strength of the str may be hindered by a shortwave trough 
currently over the northern Yellow Sea. The storm will reach its Max 
intensity in the first 12 hours of the forecast as the dual outflow 
channels persist. After tau 36 the storm will weaken due to landfall 
and interaction with the midlatitude westerlies after it crests the 
subtropical ridge axis. 
   C. Once TY 05w moves north of the ridge axis, the storm will 
encounter the midlatitude baroclinic zone located at 40n between
Taus 72 and 96. Extratropical transition will be complete between 
Taus 96 and 120 east of hokkaido. The system will accelerate after 
tau 72 under the influence of the midlatitude westerlies. The avail-
able objective aids have come into better agreement with the extended 
period forecast. 
Forecast team: Delta//