887
ACUS01 KWNS 040557
SWODY1
SPC AC 040555

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1255 AM CDT Fri Jul 04 2025

Valid 041200Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA...

...SUMMARY...
Scattered strong to severe thunderstorms with mainly a wind threat
are expected this afternoon and evening over parts of the
northern/central Plains toward the upper Mississippi Valley.
Isolated severe gusts and hail may also occur today from eastern
Oregon into portions of the northern Great Basin/Rockies.

...Synopsis...
Upper ridging initially over the Plains and Upper Midwest this
morning should gradually become more positively tilted as it shifts
eastward across the Great Lakes/Midwest and MS Valley through the
period. Multiple mid-level perturbations will round the upper ridge
today, with the most notable shortwave trough advancing eastward
from the central Rockies to the northern Plains this afternoon and
evening. A separate upper trough/low will move inland across the
Pacific Northwest towards the northern Rockies. At the surface, a
seasonably moist low-level airmass will reside to the south of a
front over the northern Plains, and east of lee troughing along much
of the length of the High Plains. The cold front is forecast to make
only slow east-southeastward progress across the northern
Plains/Upper Midwest through this evening.

...Northern Plains/Upper Midwest...
Daytime heating should encourage the development of moderate to
locally strong MLCAPE along/ahead of the front by early afternoon
across the northern Plains. Current expectations are for scattered
to numerous thunderstorms to develop along the length of the surface
boundary in the Dakotas as forcing for ascent associated with a
mid-level shortwave trough overspreads this region. While mid-level
flow and related deep-layer shear are not forecast to be overly
strong, they should still be sufficient for some updraft
organization as thunderstorm clusters merge and potentially develop
cold pools. Scattered severe/damaging winds appear probable across
parts of eastern ND into northern MN, and a Slight Risk has been
introduced for this area given the high concentration of
thunderstorms expected. This activity should spread into much of MN
through the evening before eventually weakening as it encounters a
less unstable airmass with eastward extent.

...Central Plains...
Compared to the northern Plains, generally weaker mid-level flow is
expected with southward extent across the central High Plains today.
Even so, marginally supportive deep-layer shear should aid in modest
thunderstorm organization as convection develops along/near the
surface lee trough this afternoon. Scattered to numerous
thunderstorms will likely develop in a moderately unstable airmass,
with some consolidation/upscale growth possible into the early
evening. With steepened low-level lapse rates expected, occasional
strong to severe wind gusts may occur with this activity.

...Eastern Oregon into the Northern Great Basin/Rockies...
A strong mid-level jet is forecast to overspread parts of the
northern Great Basin and Rockies today as an upper trough/low
gradually moves inland over the Pacific Northwest. In the wake of
morning showers and thunderstorms, renewed convection is anticipated
this afternoon from parts of eastern OR into the northern Great
Basin/Rockies. Although low-level moisture will remain limited,
steepened low-level lapse rates with diurnal heating and enhanced
mid-level flow should support at least isolated severe wind
potential with any convection that develops and subsequently spreads
east-northeastward through the evening. Some potential for marginal
supercells and occasional severe hail may also exist given moderate
to strong deep-layer expected from parts of eastern OR into ID and
western WY vicinity.

..Gleason/Supinie.. 07/04/2025

$$