856
ACUS01 KWNS 270059
SWODY1
SPC AC 270057

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0757 PM CDT Sun May 26 2024

Valid 270100Z - 271200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE
MID-MISSISSIPPI RIVER VALLEY INTO THE LOWER OHIO RIVER VALLEY...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
MID-ATLANTIC REGION...

...SUMMARY...
Severe storms are expected to continue this evening and overnight
across the eastern Ozark Plateau into the Ohio and Tennessee Valley.
Tornadoes, some strong to intense, and large to very large hail will
remain the primary concerns this evening before transitioning to a
widespread severe wind threat (with embedded circulations)
overnight.

...Ozarks to Lower Ohio River Valley...
Numerous supercells are ongoing as of 01 UTC across the Ozark
Plateau into the lower OH River Valley with multiple confirmed
tornadoes noted over the past 1-2 hours per recent local storm
reports and confirmed tornado warning tags. These cells are expected
to persist for the next few hours amid a gradually improving
kinematic environment (see MCD #994 for more regional details
regarding this threat).

To the northwest of the supercells, a developing severe MCS is
becoming well organized and is forecast to push east/southeast
through the overnight hours. With destabilization occurring ahead of
the MCS across the lower OH River Valley (the 00 UTC BNA sounding
shows rich low-level moisture with ~1500 J/kg MLCAPE), the potential
for widespread damaging to severe winds appears to be increasing.
Recent CAM guidance, including experimental WoFS ensemble guidance,
appears to support this idea and depicts a swath of severe winds
(including the potential for significant wind gusts up to 75 mph)
extending well into southern IL/IN and much of KY. Consequently, a
wind-driven expansion of the Moderate risk area is warranted across
parts of the lower OH River Valley. Despite the linear storm mode,
favorable low-level SRH should support the potential for embedded
circulations. See MCD #995 for more short-term details regarding the
developing MCS and wind threat.

....Mid-Atlantic Region...
A residual QLCS continues to produce damaging winds across the
Mid-Atlantic region despite outrunning favorable deep-layer wind
shear. Downstream buoyancy remains favorable for some degree of line
maintenance heading into the late evening hours, which should
continue to support a damaging wind threat. Wind probabilities have
been increased across this region to reflect this potential, though
the threat is expected to diminish overnight amid increasing
nocturnal stabilization and displacement from stronger forcing for
ascent to the west. See MCD #993 for additional details.

..Moore.. 05/27/2024

$$