[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT42 KNHC 162052
TCDAT2

TROPICAL STORM BILL DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL022015
400 PM CDT TUE JUN 16 2015

After an earlier westward wobble, Bill is now moving toward the
north-northwest or north based on Doppler radar data. My best
estimate for a storm motion is 330/08 kt. Bill is expected to move
north-northwestward tonight and turn toward the north over
north-central Texas on Monday as the cyclone moves through a break
in the subtropical ridge. By 36-48 hours, Bill is forecast to get
caught up into the mid-latitude westerlies and accelerate off to the
northeast and east-northeast. By 120 hours, the remnant circulation
is expected to merge with a frontal system across the Ohio Valley
region. The global models are in good agreement on this developing
scenario and the NHC forecast track is just an update of the
previous one, and lies close to a blend of the slower GFS, ECMWF,
and UKMET global models.

Although the inner-core banding structure of Bill has improved in
radar imagery, the cyclone is expected to slowly weaken as the
system continues to move farther inland. Bill should weaken to a
tropical depression by Wednesday morning and become a remnant low by
Wednesday evening when the system is moving across northern Texas.
The GFS, ECMWF, and UKMET models now suggest that baroclinic forcing
associated with an upper-level trough will help maintain the
post-tropical remnants as a distinct entity for a few days before
being absorbed by a frontal system by day 5.

Tropical-storm-force winds and heavy rains continue to occur well
away from the center.  The main hazard from Bill is expected to be
heavy rainfall and flooding across portions of eastern Texas and
eastern Oklahoma over the next day or two.  Please see products from
your local National Weather Service office for more information on
the flood threat.

FORECAST POSITIONS AND MAX WINDS

INIT  16/2100Z 28.4N  96.8W   45 KT  50 MPH...INLAND
 12H  17/0600Z 29.9N  97.5W   30 KT  35 MPH...INLAND
 24H  17/1800Z 32.0N  97.7W   25 KT  30 MPH...INLAND
 36H  18/0600Z 33.6N  97.1W   25 KT  30 MPH...POST-TROP/INLAND
 48H  18/1800Z 34.7N  95.7W   20 KT  25 MPH...POST-TROP/INLAND
 72H  19/1800Z 36.7N  92.0W   15 KT  15 MPH...POST-TROP/INLAND
 96H  20/1800Z 39.0N  86.0W   15 KT  15 MPH...POST-TROP/INLAND
120H  21/1800Z...ABSORBED BY FRONTAL SYSTEM

$$
Forecaster Stewart
This weather bulletin was brought to you by:
www.nashvilleweather.net