ACUS01 KWNS 082001
SWODY1
SPC AC 081959

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0259 PM CDT Wed Jul 08 2026

Valid 082000Z - 091200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
NORTHEAST COLORADO...SOUTHWEST NEBRASKA...AND NORTHWEST KANSAS...

...SUMMARY...
Thunderstorms with severe wind gusts and hail will be possible this
afternoon and evening across parts of the central Plains, and from
the Missouri Valley into the upper Mississippi Valley. Isolated
severe gusts may also occur from the northern Great Basin into the
northern High Plains, from North Carolina into southern Virginia,
and over southeast Arizona.

...20Z Update...
The forecast remains on track, and only minor changes were made with
this update. 

The SLGT risk in the central High Plains was expanded northward into
northeast WY, southwest SD, and far southeast MT -- driven by
15-percent wind probabilities. High-based thunderstorms are already
forming/strengthening along the high terrain in northern WY and
southern MT. Given steep lapse rates/moderate buoyancy and an
elongated/straight hodograph (around 40 kt of effective shear)
downstream, a few organized clusters will pose a risk for scattered
severe wind gusts and isolated large hail. See MCD #1543 for more
information. 

Farther east, the SLGT risk in the Midwest was expanded northward
into southeastern MN and central WI, based on the latest placement
of the surface boundary. Thunderstorm clusters will pose a risk for
damaging wind gusts through the afternoon. As these storms track
southward into a moist/unstable air mass across northern IA this
evening/tonight, upscale growth could promote a locally greater
concentration of damaging wind gusts.

..Weinman.. 07/08/2026

.PREV DISCUSSION... /ISSUED 1112 AM CDT Wed Jul 08 2026/

...WI/MN/IA...
A fast-moving shortwave trough is moving eastward across ND.  As
this system approaches the western Great Lakes region this
afternoon, thunderstorms are expected to form along a surface
boundary extending from southeast MN into central WI.  A moist and
very unstable air mass will be present along the boundary, aiding in
the development of a few severe storms.  Sufficient deep-layer shear
will promote supercell structures capable of damaging wind gusts and
hail.  An isolated tornado or two is also possible.  This activity
will build westward along the boundary into northern IA by early
evening.  A cluster or two of this activity could congeal into
bowing structures with a continued severe wind risk this evening.

...High Plains...
The upper ridge over the Rockies has weakened today, resulting in
stronger westerly flow into parts of WY/CO/NE/KS.  Scattered
high-based thunderstorms are expected to form by mid-afternoon over
the mountains and foothills of CO/southern WY and spread eastward
into the Plains.  Moisture will be limited near the foothills, but
weak easterly surface winds will maintain 40s dewpoints in eastern
CO, leading to convective intensification.  Most CAM solutions show
thunderstorms capable of locally severe wind gusts tracking eastward
through the evening into parts of southwest NE and western KS before
dissipating after midnight.

...Northern Great Basin/Northern Rockies...
Moderately strong westerly flow aloft, steep low-level lapse rates,
and ample mid-level moisture will result in conditions favorable for
scattered high-based thunderstorms over a relatively broad area this
afternoon and evening.  Gusty/damaging winds will be possible with
the strongest storms.

...Southeast AZ...
Widely scattered high-based thunderstorms are expected to form over
the higher terrain of southeast AZ and propagate south-southwestward
through the early evening.  Inverted-v profiles will promote a risk
of gusty/damaging winds in a few of the storms.

$$