ACUS03 KWNS 090727
SWODY3
SPC AC 090726

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0226 AM CDT Tue Jun 09 2026

Valid 111200Z - 121200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
MISSOURI THROUGH EASTERN IOWA...NORTHERN AND CENTRAL ILLINOIS AND
SOUTHERN WISCONSIN INTO WESTERN LOWER MICHIGAN...

...SUMMARY...
Scattered to numerous severe storms capable of potentially strong
tornadoes, large hail, and destructive winds appear likely from
portions of the lower Missouri and mid Mississippi Valleys into the
upper Great Lakes. More sporadic occurrences of damaging wind and
large hail are possible across the southern Plains, upper Ohio
Valley and lower Great Lakes toward the Mid-Atlantic Coast.

...Synopsis...

A potent short-wave trough initially over the central High Plains
Thursday morning is forecast to accelerate through the upper Great
Lakes with a trailing perturbation moving through the central Plains
into mid MS Valley Thursday night. Both disturbances will be located
on the cyclonic aside of an unseasonably strong mid-level jet with
500-mb wind speeds approaching 70-80 kt. The 00z models have slowed
the progression of the mid-level wave, as well as the associated
surface low, which is forecast to develop from northeast KS along
the synoptic front or remnant outflow from overnight storms into
southern WI by afternoon and northern lower MI or the UP by Thursday night.

...Lower Missouri Valley/Mid Mississippi Valley into the Upper Great Lakes...

A very moist boundary layer will combine with steep mid-level lapse
rates to yield a moderate to strongly unstable air mass by afternoon
to the south of the composite surface boundary. A cluster of mainly
elevated thunderstorms is expected to be ongoing Thursday morning
across portions of the mid MO Valley, to the northeast of the
surface low. Those storms are expected to become progressively more
surface-based and intense by mid to late morning into afternoon
while rapidly moving northeast, coincident with the surface low.
Forecast sounding within the inflow environment of those storms
indicate strong low-level and deep-layer shear, supportive of
supercells and bowing segments capable of potentially strong
tornadoes, in addition to large hail and damaging winds.

Additional severe storms are expected to develop along the trailing
front from the lower MO and mid MS Valleys southwest through the
Ozarks into southern Plains. The progressive nature of the mid-level
system suggests the potential for long-tracked supercells and bowing
structures capable of tornadoes and swaths of destructive winds.

...Upper Ohio Valley and Lower Great Lakes to the Mid-Atlantic Coast...

While large-scale forcing for ascent is expected to remain
relatively weak, model guidance indicates scattered, afternoon storm
development from the lee of the lower Great Lakes through the
central Appalachians to the vicinity of a lee trough in the
Mid-Atlantic. Vertical shear is expected to remain relatively weak;
however, the presence of a moist and moderately unstable air mass
will support wet microburst activity and an associated risk for
sporadic damaging winds.

..Mead.. 06/09/2026

$$
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 * Origin: Capitol City Online (618:250/10)