651
ACUS01 KWNS 180053
SWODY1
SPC AC 180051

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0751 PM CDT Tue Sep 17 2024

Valid 180100Z - 181200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE HIGH PLAINS...

...SUMMARY...
Thunderstorms capable of producing scattered to numerous severe wind
gusts and hail will continue to develop across the High Plains this
evening. Some of the wind gusts may be significant (75+ mph).

...Southern and Central High Plains...
A mid-level low is evident on water vapor imagery over the northern
Rockies, with cyclonic southwesterly flow located from the Four
Corners into the central and northern Plains. Ahead of the trough, a
band of strong large-scale ascent appears to be spreading into the
central High Plains, where a large plume of mid-level moisture is
located. Thunderstorms are ongoing ahead of this band of ascent, and
are moving into a moderately unstable airmass where MLCAPE is
estimated to be in the 1000 to 2000 J/kg range. Concerning the shear
environment, regional WSR-88D VWPs in east-central Colorado have 0-6
km shear from 40 to 50 knots, with some directional shear in the
lowest 3 km. In addition, the RAP has a strengthening low-level jet
analyzed from far eastern Colorado and western Kansas northward into
southeastern South Dakota. As the low-level jet continues to
strengthen, the lift, shear and instability will continue to support
severe thunderstorm development over the southern and central High
Plains this evening. In response, an organized line segment will
continue to move eastward across western Nebraska, western Kansas
and the Texas Panhandle, where scattered severe wind gusts are
expected. Wind gusts above 70 knots will be possible along the more
organized parts of the line. The threat should persist into the mid
to late evening.

...Northern High Plains...
Water vapor imagery shows an upper-level low over eastern Idaho,
with divergent mid-level from the south and south-southeast across
much of the northern High Plains. An axis moderate instability is
analyzed from central North Dakota into northeastern Montana, where
MLCAPE is estimated in the 2000 to 3000 J/kg range. Thunderstorms
are ongoing near the instability axis in northeastern Montana.
Additional storms have developed further south near the South
Dakota-Wyoming state line. The latest WSR-88D VWP at Glasgow,
Montana has easterly flow at the surface, with a sharply veering
wind profile in the low-levels. 0-6 km shear is estimated to be near
40 knots. This environment, along with steep low to mid-level lapse
rates should continue to support a severe threat for several more
hours. A potential for severe wind gusts and isolated large hail
will exist with the stronger storms.

..Broyles.. 09/18/2024

$$