247
ACUS01 KWNS 020530
SWODY1
SPC AC 020529

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1229 AM CDT Wed Jul 02 2025

Valid 021200Z - 031200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN ROCKIES/HIGH PLAINS...GREAT BASIN...AND UPPER
MIDWEST/GREAT LAKES...

...SUMMARY...
Isolated strong to severe thunderstorms may occur today across parts
of the northern Rockies/High Plains, Great Basin, and Upper
Midwest/Great Lakes.

...Northern Rockies/High Plains...
Ample daytime heating is forecast today on the northern/western
periphery of upper ridging centered over the Plains. Current
expectations are that high-based thunderstorms will develop
initially over the higher terrain of the northern Rockies, and
subsequently spread east-northeastward through the evening. Even
with low-level moisture and instability expected to remain
modest/weak, a very well-mixed boundary layer will be in place
across this region and the adjacent High Plains. Thunderstorm
downdrafts will likely be able to efficiently mix modestly enhanced
mid-level flow to the surface, and isolated severe gusts should
occur with this activity as it moves across MT and vicinity through
this evening. Confidence in a more concentrated corridor of severe
winds was not high enough to include greater severe probabilities
with this update.

...Great Basin...
Modestly enhanced southerly flow will be present today over parts of
the Great Basin in association with a decaying/weak upper trough/low
over CA and the western Great Basin. While some cloud cover may
limit diurnal heating and related steepening of low-level lapse
rates to some extent this afternoon, it still appears probable that
a generally well-mixed boundary layer will exist across much of NV
into western UT. At least scattered thunderstorms should spread
northward across these areas this afternoon/evening, with isolated
severe wind gusts possible.

...Upper Midwest/Great Lakes...
As upper ridging builds over the Plains today, a shortwave trough
over Ontario will dig southeastward and provide glancing large-scale
ascent over parts of the Upper Midwest and Great Lakes. A seasonably
moist low-level airmass is expected to remain over most of these
regions, and daytime heating will likely aid in the development of
moderate to strong instability along/south of a front. Some
enhancement to the mid/upper-level west-northwesterly flow should
support sufficient deep-layer shear for organized thunderstorms, and
a conditionally favorable environment for severe thunderstorms
remains apparent. Primary uncertainty remains overall convective
coverage given generally weak large-scale ascent. Have therefore
maintained the Marginal Risk for severe hail/wind across these
regions with minimal changes.

...Eastern North Carolina...
Weak upper troughing will advance eastward today across the southern
Mid-Atlantic and Carolinas as a surface cold front likewise moves
slowly east-southeastward across these areas. Poor lapse rates aloft
will likely limit updraft strength, and deep-layer shear is also
expected to remain weak. While thunderstorms should develop through
the afternoon along/ahead of the front across eastern NC and
vicinity, the potential for damaging winds currently appears too
limited to include low severe probabilities at this time.

..Gleason/Lyons.. 07/02/2025

$$