msgid/genadmin/navpacmetoccen Pearl Harbor hi/jtwc//
subj/prognostic reasoning for tropical storm 02w warning nr 05//
rmks/
1. For meteorologists.
2. 12 hour summary and analysis.
   A. Recent animated multispectral imagery reveals consolidation
of the system as it tracks into the South China Sea northwestward 
from palawan. A mesoscale anticyclone has continued to build over
the system providing radial outflow in conjunction with a stronger
poleward outflow channel. The system is currently south of the
upper level subtropical ridge axis and in favorable sea surface
temperatures and ocean heat content. 
   B. The current storm intensity is based on Dvorak satellite
intensity estimates of 35 knots from pgtw and knes. The intensity
has remained steady over the past 12 hours due to interaction
with palawan during the early stages of the system's lifecycle.
Ts 02w is tracking northwestward south of a strong east-to-west
oriented subtropical ridge axis. 
3. Forecast reasoning
   a. The forecast reasoning remains unchanged from the previous
prognostic reasoning bulletin.  
   B. A shallow short wave trough will transit to the east of
southeastern China within the next 06 to 12 hours, allowing for
the mid-level steering ridge to build in from the east and steer
the system more westward. A second mid to upper-level midlatitude
trough transiting across southern China will begin to weaken the
subtropical steering ridge, allowing the system to take a pro-
gressive northward track along the western periphery of the ridge.
Model guidance is in good agreement with this scenario. The storm
will gradually intensify through the first 72 hours in a favorable
environment. 
   C. Beyond tau 72 the track will continue to gain more of a
northward component as the system nears the subtropical ridge axis.
The system is expected to weaken in close proximity to a baroclinic
zone located to the north of hainan. Land interaction with hainan,
coupled with low ocean heat content and higher shear values, will
account for the weakening. 
Forecast team: Bravo//