discussion sacada del wunderground:
msgid/genadmin/navpacmetoccen Pearl Harbor hi/jtwc//
subj/prognostic reasoning for typhoon 07w warning nr08//
rmks/
1. For meteorologists.
2. 12 hour summary and analysis.
A. Typhoon (TY) 07w (Pabuk) has intensified and consolid-
ated further over the past 12 hours and has been upgraded to
typhoon status. The system continues to track quickly westward
under a strong mid-level subtropical ridge positioned north.
The dynamic models have become more consistent and are in good
agreement with a westward track.
B. TY 07w is located approximately 285 nm southeast of
Taipei, Taiwan, and has tracked westward at 17 knots over the
past 06 hours. The 06/12z 500mb analysis depicted a strong
steering ridge north of the system with a weakness located east
of Shanghai, China. The 07/00z analysis now indicates that the
ridge has strengthened and now extends westward into China. The
500mb winds over the Okinawa area are east-southeasterly at 20-
30 knots and are southeast at 10-15 knots over eastern China.
TY 07w has maintained good equatorward outflow but poleward
outflow continues to be restricted due to convergence by upper
level ridging north ofv the system. The current intensity is
based on Dvorak estimates of 65 knots from pgtw and knes (jma
currently lower at 55 knots). The current position is based on
a 062104z SSMI image which depicts a curved convective band
over the eastern quadrant. This supports the current track speed
and positioning along 22n.
3. Forecast reasoning.
A. Based on the latest upper air analyses, the ridge supports
a westward track until landfall on Taiwan. Therefore, the track
has been shifted south of the previous forecast and indicates a
more logical westward track overall.
B. TY 07w is forecast to continue tracking westward and will
significantly weaken as it tracks across Taiwan after tau 12.
The system will further weaken after tau 36 when it moves into
China and is expected to dissipate after tau 48. Dynamic aids are
in good agreement with this track. TY 07w should continue to
strengthen for the next 12 hours.
Forecast team: Bravo//
nnnn
http://www.wunderground.com/tropical/wp200707.disc.html