Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1221 AM CDT Thu Aug 10 2023

Valid 111200Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MID MS VALLEY AND UPPER MIDWEST...

...SUMMARY...
Severe thunderstorms capable of large hail, damaging gusts, and
perhaps a tornado or two are possible across portions of the Middle
Mississippi Valley and Upper Midwest on Friday.

...Central Plains into the Upper Midwest/Upper Great Lakes...
Upper ridging is expected to build across the southern Plains and
Southwest on Friday, as a pair of shortwave troughs traverse the
belt of enhanced flow north of this ridging from the northern Plains
into the Northeast. Lead shortwave is expected to move quickly
through northern New England early in the period, while the
westernmost shortwave drops from the Canadian Prairie Provinces
through the Upper Midwest and Upper Great Lakes.

A moist air mass is expected to be in place ahead of this shortwave,
with dewpoints ranging from the low 70s across eastern KS to the mid
60s across Lower MI. Strong diurnal heating will combine with this
low-level moisture to support moderate to strong buoyancy across the
entire region by the early afternoon. Surface low associated with
the approaching shortwave trough is forecast to move across northern
WI during the afternoon. An attendant cold front is expected to move
across IA and southern WI/northern IL during same period.
Convergence along this front will be minimized by veered surface
winds preceding the frontal passage. However, only minimal
convective inhibition is anticipated, and there will likely be
enough lift near the front for isolated to widely scattered
thunderstorm development. The moderate to strong vertical shear in
place will support updraft organization, with large hail and
damaging gusts possible with the more robust/mature cells. There
will also likely be enough low-level shear to support a
low-probability tornado threat. Warm-air advection is also expected
to support thunderstorms across lower MI, where environmental
conditions support an isolated severe potential.

Thunderstorms are also expected to develop across MN late Friday
afternoon as the shortwave moves through the region. Robust
mid-level flow associated with this shortwave will result in a
strongly sheared environment (i.e. 50 to 60 kt of effective bulk
shear). This strong shear will support supercells capable of large
hail and damaging gusts. Some potential for upscale growth will
exist with this activity.

...Southeast States...
A very moist air mass will remain in place across the Southeast,
with moderate to strong buoyancy expected to develop by
mid-afternoon. The glancing influence of a weak vorticity maximum
progressing through the TN into the Carolinas and/or outflow from
preceding storms may aid in thunderstorm development after the
airmass destabilizes. Shear will be modest, limiting storm
organization, but scattered to numerous storm coverage combined with
an outflow-dominant storm mode will support a risk for isolated
damaging gusts across much of the region.

..Mosier.. 08/10/2023