170
ACUS01 KWNS 251940
SWODY1
SPC AC 251939

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0239 PM CDT Tue Jun 25 2024

Valid 252000Z - 261200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
PLAINS TO THE MID-MISSISSIPPI AND OHIO VALLEYS...

...SUMMARY...
Damaging wind gusts and large hail are possible across parts of the
central/southern Great Plains and Midwest into this evening.

...20z Update...

The ongoing outlook remains on track. Only  minor adjustments were
made to the Marginal (level 1 of 5) risk in South Dakota to account
for current trends where convection is developing. Other changes
were made to the 10 percent general thunderstorm line based on
latest observations and trends. For more details, refer to previous
outlook discussion below. For short term severe potential across
portions of SD reference MCD 1410.

..Leitman.. 06/25/2024

.PREV DISCUSSION... /ISSUED 1125 AM CDT Tue Jun 25 2024/

...OH Valley...
A large but weakening MCS is spreading southeastward across parts of
OH/IN/IL, with a broken line of strong cells along the leading line.
 The western flank of this activity over IL may intensify by mid
afternoon, spreading into parts of eastern MO and southern IL/IN,
posing a risk of damaging wind gusts and hail.

...IA/MO/NE...
Farther west, a hot, humid air mass is present today across much of
MO, southern IA, and eastern NE.  Widely scattered intense
thunderstorms are expected to form later this afternoon - mainly
along a boundary from southern IA into eastern NE.  These storms
would be in a sufficiently sheared environment for supercell
structures capable of very large hail and damaging winds.  Storms
are expected to sag southward through the evening.  Models differ on
evolution of storms overnight, with some solutions suggesting a
larger MCS building into southern MO by the end of the period.

...SD/NE...
An axis of southeasterly low-level winds and dewpoints in the mid
60s to 70s extends from the Black Hills region into southeast SD and
central NE.  Strong heating in this area will result in ample CAPE,
leading to scattered afternoon and evening storms.  Steep mid-level
lapse rates and moderately strong west-northwest flow aloft will
promote supercells capable of very large hail, damaging winds, and
perhaps a tornado.

$$