Clearpost.online It's your post, so post it!

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0252 PM CDT Tue Aug 27 2024

Valid 272000Z - 281200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE
GREAT LAKES AND UPPER MISSISSIPPI VALLEY...

...SUMMARY...
Severe thunderstorms capable of damaging thunderstorm winds and
occasional large hail and a tornado or two are possible across the
Great Lakes region and portions of the Midwest through tonight.

...20z Update...
The prior forecast remains largely on track with minor changes. The
Slight and Marginal risk area over parts of WI was trimmed behind
extensive convection ongoing over the Lake and northern MI. Ongoing
severe storms over parts of the Great Lakes are expected to
gradually expand in coverage and intensity over southern lower MI,
northern IL and IN through the remainder of the afternoon and into
the evening/overnight. The primary risk remains damaging winds
associated with organized clusters or bowing segments, but hail and
a tornado or two will also remain possible.

Farther south into parts of the Mississippi Valley and eastern
Plains, additional storm development/intensification is probable
this afternoon within a warm and unstable air mass ahead of a weak
cold front. Vertical shear is somewhat weaker displaced south of the
main shortwave trough, but robust boundary-layer heating should
suffice for periodic intensification of multicell storms. At least
some damaging wind or hail risk may develop with clusters of strong
to severe storms across eastern KS and south-central IA from this
afternoon through the evening.

..Lyons.. 08/27/2024

.PREV DISCUSSION... /ISSUED 1142 AM CDT Tue Aug 27 2024/

...Great Lakes/Midwest/Central Plains...
A rather co*plex mesoscale scenario exists particularly across the
Great Lakes region, influenced by multiple MCSs/outflows since last
evening. Multiple MCVs are apparent across the region including
western Upper Michigan, potentially including an MCV with evolving
asymmetric quasi-linear convection across east-central Wisconsin
late this morning. Within a zone of pre-frontal confluence/augmented
outflow, MCS persistence and further upscale/southward peripheral
growth is possible into Lower Michigan/northern Illinois into a very
unstable air mass, but this is far from certain. For additional
short-term information, see Mesoscale Discussion 2013.

Where storm clusters do develop and intensify regionally, ample
buoyancy, particularly south of the aforementioned late-morning MCS,
and sufficient deep-layer shear will support damaging wind and
isolated large hail potential. The severe threat could reach as far
as the Lake Ontario vicinity late tonight/early Wednesday.

Farther southwest, nearer to the cold front and potentially
augmented by residual outflow, CAPE and especially vertical shear
will be weaker from southeast Iowa/western Illinois into northern
Missouri and eastern Kansas/southeast Nebraska. A few organized
multicells are possible atop a strongly heated boundary layer, with
strong wind gusts and severe hail possible.