ACUS03 KWNS 270721
SWODY3
SPC AC 270721

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0221 AM CDT Tue Apr 27 2021

Valid 291200Z - 301200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE OH VALLEY...

...SUMMARY...
Isolated strong to severe thunderstorms are possible across the
middle and upper Ohio Valley on Thursday.

...Synopsis...
A northern-stream shortwave trough is forecast to extend from
northwest Ontario into central KS early Thursday morning. A
southern-stream upper low will likely be centered over the southern
High Plains at the same time. The northern-stream system is expected
to remain progressive throughout the day, moving through the Upper
MS Valley, Upper Great Lakes, and much of the OH Valley. In
contrast, the southern-stream system is only expected to make
minimal eastward progression, likely ending the period centered over
the Big Bend region of TX.

A surface low associated with the northern-stream shortwave is
expected to be centered over the Mid MS Valley early Thursday,
before then quickly progressing northeastward throughout the day. As
it moves northeastward, an attendant cold front will sweep
southeastward through the Mid MS and OH Valleys. Low to mid 60s
dewpoints will likely precede this front across the OH Valley,
contributing to modest instability despite poor mid-level lapse
rates and abundant cloud cover. Moderate to strong mid-level flow
will also be in place over the OH Valley, with the resulting
environmental conditions that could support a few strong to severe
storms. Damaging wind gusts and/or a brief tornado are the primary
threats.

..Mosier.. 04/27/2021

$$