Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0753 PM CDT Fri Sep 04 2026
Valid 050100Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE SOUTHERN GREAT LAKES INTO THE MID AND UPPER OHIO VALLEY...
...SUMMARY...
Severe storms capable of scattered occurrences of damaging wind with
gusts up to 70 mph are expected across the southern Great Lakes and
mid/upper Ohio Valley overnight. More isolated severe storms capable
of large hail and severe wind gusts may occur over portions of the
northern Plains. Strong to severe storms with a risk for damaging
wind gusts may persist for another couple of hours in the southern
Mid-Atlantic.
...Great Lakes into the Ohio Valley...
Forcing for ascent attendant to a weak mid-level disturbance
cresting the mid-level ridge is contributing to a couple of areas of
thunderstorm activity this evening over portions of eastern IA and
central WI. The 00Z DVN sounding is likely representative of the
inflow air mass for these storms, featuring a moist boundary layer
and relatively steep mid-level lapse rates with MLCAPE of around
4000 J/kg. It remains unclear whether a subset of the current storms
will grow upscale into a cold-pool-driven MCS overnight, or whether
additional storms will develop farther to the east across portions
of southern Lake MI and southwest Lower MI in the next few hours.
Either way, there is a consistent model signal for a bowing
convective system to evolve across portions of northeast IN into OH,
along the cool side of a composite surface boundary extending from
central WI through central IN into eastern KY.
Regional VWPs and 00Z soundings indicate the presence of 30-35 kt
northwest winds in the mid levels along the axis of the prospective
MCS track, which will contribute to sufficient deep-layer shear for
cold-pool organization. As such, a corridor of more concentrated
wind damage appears possible along with severe gusts up to 70 mph.
...Northern Plains...
A cluster of mainly elevated thunderstorms is ongoing this evening
over north-central SD, with that activity likely rooted above a warm
capping inversion observed by the 00Z ABR sounding. Additional
storms are expected to develop overnight along a nocturnally
strengthening low-level jet, where warm advection and moisture
transport will be maximized. Mid-level flow and resultant vertical
shear are forecast to weaken overnight owing to the proximity of the
mid-level ridge. However, the presence of steep mid-level lapse
rates and associated moderate to strong instability suggests the
potential for isolated severe storms capable of large hail and
severe wind gusts. As such, 5% wind and hail probabilities have been
included in this forecast update.
...Southern Mid-Atlantic...
Clusters of strong to severe thunderstorms ongoing over portions of
southeast VA into north-central and northeast NC will remain capable
of mainly damaging wind gusts for the next hour or two. Thereafter,
storms are expected to gradually weaken as the boundary layer
stabilizes.
..Mead.. 09/05/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVL0vh
