SPC Jul 3, 2025 0100 UTC Day 1 Convective Outlook

SPC 0100Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0759 PM CDT Wed Jul 02 2025

Valid 030100Z - 031200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
MONTANA...

...SUMMARY...
Isolated to widely scattered severe thunderstorm gusts remain
possible across parts of eastern Oregon into Idaho and Montana this
evening. Isolated severe thunderstorms may also occur over portions
of the Upper Midwest/Great Lakes.

...Eastern Oregon into the Northern Rockies/High Plains...
Convection has developed this afternoon/evening along the western
and northern periphery of upper troughing centered over the High
Plains. Surface observations and various forecast soundings suggest
a very well mixed airmass is present from eastern OR into the
northern Rockies/High Plains, with surface temperature/dewpoint
spreads of 30-40+ F common. While instability and deep-layer shear
are both forecast to remain fairly modest, there may be some loosely
organized clusters posing a threat for isolated to scattered severe
winds this evening. The greatest concentration of thunderstorms and
severe winds may still focus across parts of central/eastern MT over
the next several hours, where the Slight Risk has been maintained.
See Mesoscale Discussion 1544 for more details on the short-term
severe threat across this area.

...Upper Midwest/Great Lakes...
Widely scattered thunderstorms should continue across parts the
Upper Midwest and Great Lakes this evening, as the glancing
influence of upper troughing over Ontario and the northern Great
Lakes overspreads this region. Modest low-level flow per area VWPs
gradually veers to northwesterly at mid/upper levels, which is
supporting around 30-35 kt of deep-layer shear. Occasional
thunderstorm organization has been noted with the ongoing activity
given a sufficiently unstable airmass, and isolated damaging
winds/hail should remain possible for a couple more hours before
convection eventually weakens later this evening.

...Great Basin/Southwest...
Convection earlier today has largely overturned the airmass across
much of NV into western UT. Occasional strong to severe gusts will
remain possible with any ongoing/additional convection across the
Sierra into the Great Basin and Southwest where low-level lapse
rates remain steepened. But, overall severe wind potential is
expected to remain rather isolated, with a small Marginal Risk for
wind maintained across parts of southern NV and vicinity where
low-level lapse rates remain steepened amid 30-40 kt of southerly
deep-layer shear.

..Gleason.. 07/03/2025

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