382
ACUS03 KWNS 300728
SWODY3
SPC AC 300727

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 AM CDT Tue Apr 30 2024

Valid 021200Z - 031200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE UPPER MISSISSIPPI VALLEY INTO THE SOUTHERN PLAINS...

...SUMMARY...
Scattered strong to severe storms will be possible on Thursday from
parts of the upper Mississippi Valley into the southern Plains.

...Synopsis...
On Thursday, a shortwave trough is forecast to move across the
northern Plains during the day, and across the upper MS Valley into
Friday morning, becoming negatively tilted. Meanwhile, the primary
surface low is expected to move from eastern NE across IA and into
WI, with a secondary trough extending northwestward across MN and
ND. Extending south of the low, a cold front will stretch from IA
into OK during the afternoon, with a plume of low to mid 60s F
dewpoints ahead of the front. Southwesterly winds of 40+ kt at 850
will aid warming and destabilization across IA and northern IL
during the day as a warm front lifts north.  To the south, a dryline
will remain over west-central Texas, with a very moist and unstable
air mass to the east.

...Upper MS Valley into KS/MO...
Substantial/ongoing rain and thunderstorms are expected Thursday
morning from the front/outflow near the NE/IA border northeastward
along and north of the warm front across IA, southern MN and WI.
Predictability in terms of placement is low, but any ongoing MCS may
be capable of strong to locally severe gusts, and marginal hail
cannot be ruled out north of the warm front with 1000+ MUCAPE.
Additional storms may develop southward along the front into KS and
MO during the day with the help of heating. However, the ejecting
wave to the north will tend to limit large-scale support with
southward extent. Still, areas of gusty winds or marginal hail will
be possible.

...OK into TX...
Heating along the dryline, and perhaps ahead of the sagging cold
front, will likely yield scattered daytime storms, though shear will
be relatively weak over OK. Stronger high-level winds will exist
over TX beneath the southern-stream jet extending northeastward out
of Mexico, and this may favor a few storms with large hail along the
dryline in TX. Cool midlevel temperatures and straight hodographs
will also favor hail. A small/targeted Slight Risk could be added
for parts of the TX dryline in later outlooks as predictability
increases.

..Jewell.. 04/30/2024

$$