Valid 152000Z – 161200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
…SUMMARY…
Organized severe thunderstorms are not expected across the
contiguous U.S. today.
…Discussion…
Primary change to current outlook has been to trim general
thunderstorm area over the Great Lakes and OH Valley. In wake of
shortwave trough, forcing for ascent will be limited to weak
convergence and weak warm advection along and in advance of a
southeast-moving cold front the remainder of the period. As a
result, coverage of any additional thunderstorms is expected to be
sparse.
..Dial.. 09/15/2019
.PREV DISCUSSION… /ISSUED 1052 AM CDT Sun Sep 15 2019/
…Far southeast AZ and southwest NM…
A couple stronger storms are possible near the southeast
AZ/southwest NM/international border area to the south of a
low-amplitude shortwave impulse slowly moving from the Mogollon Rim
to the southern Rockies. Pockets of greater insolation should be
confined to the international border with abundant cloud
coverage/remnant stratiform rain farther north closer to the
shortwave impulse. Scattered thunderstorms will develop later this
afternoon as destabilization occurs within the cloud breaks.
Moderate buoyancy with MLCAPE of 1000-1500 J/kg in conjunction with
effective shear around 25 kt may support a couple updrafts
possessing weak/transient mid-level rotation. Amid modest mid-level
lapse rates, this setup would most likely yield small hail and
locally strong gusts. Overall threat appears too limited to warrant
a severe risk area.
$$