042
ACUS02 KWNS 010551
SWODY2
SPC AC 010549

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1249 AM CDT Wed May 01 2024

Valid 021200Z - 031200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE UPPER MISSISSIPPI VALLEY SOUTHWESTWARD INTO PARTS OF NORTHWEST
TEXAS...

...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 morning, a shortwave trough will be located over the
northern High Plains, with a leading 70+ kt 500 mb speed max over NE
and SD. This wave will move toward the upper MS Valley in
negative-tilt fashion, deepening all the while. To the south,
relatively weak midlevel flow will exist from the Southwest into the
southern Plains, but a high-level jet will extend from Mexico into
TX. A midlevel wave will also exist over central and eastern TX
early, with associated heavy rains forecast per WPC outlooks.

At the surface, low pressure is forecast to be located near
northwest MO, with a trough extending into northwest TX early in the
day. The primary surface low will move northeastward across IA and
into WI late in the day, while the southern extension of the
trough/wind shift makes slow southward progress across OK and
northern TX.

A warm front will lift north across IA and IL ahead of the low, with
at least low 60s F dewpoints into eastern IA and northern IL by
afternoon. While a southwesterly low-level jet will aid theta-e
advection early, wind fields around 850 mb will generally weaken as
the upper trough continues northeastward.

...Mid MO Valley into the Upper MS Valley...
Thunderstorms are likely to be ongoing along the cold front from
southeast NE into northeast KS, and across much of IA where a 50+ kt
low-level jet will enhance lift and theta-e advection. Behind this
initial activity, areas of heating will lead to a diurnal increase
in storms from IA into MO near the cold front and/or near residual
outflows. Shear will decrease over time as the shortwave trough
lifts north; however, low-level shear near the warm front may still
favor a low-end tornado risk during the afternoon. Otherwise,
localized strong gusts or marginal hail may occur with storms along
the cold front.

...Central and Western OK into northern TX...
Heating will occur ahead of the sagging boundary and along a
dryline, where 60s F dewpoints will remain in place. Forecast
soundings indicate moderate instability will develop, with over 2000
J/kg MUCAPE expected. However, midlevel lapse rates will not be
particularly steep, owing to possible midlevel subsidence behind the
east TX wave. Still, strong heating will lead to an uncapped air
mass, and sufficient convergence near the boundaries should lead to
at least isolated strong to severe storms. Locally strong downbursts
or hail may occur with slow-moving, southeastward-propagating storms
or small clusters.

..Jewell.. 05/01/2024

$$