529
ACUS01 KWNS 200513
SWODY1
SPC AC 200512

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1212 AM CDT Sun Apr 20 2025

Valid 201200Z - 211200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
ARKANSAS INTO CENTRAL MISSOURI...

...SUMMARY...
Severe thunderstorms are expected on Sunday from east Texas into far
southeast Iowa and Illinois. A strong tornado and damaging wind
potential will exist from central Arkansas into central Missouri.

... Synopsis ...

A seasonably strong mid-level low will eject from the southern
Rockies/west Texas northeast toward the western Great Lakes on
Sunday. As the mid-level low impinges on the western periphery of
the Bermuda High the increasing height gradient will result in the
development of 90-100 knot mid-level jet across northeast Oklahoma
by late morning. This jet will slowly weaken as it moves northeast
through the day.

A surface cyclone will deepen through the day as it also lifts
northeast from Oklahoma toward Wisconsin. An attendant cold front to
the south of this low will push east through Oklahoma into Missouri
and Arkansas during the afternoon, and the attendant warm front will
lift north into northern Missouri and central Iowa. Increasing
southerly low-level flow, including a 50-60 knot low-level jet, will
advect low 60sF dewpoints into northern Missouri and mid 60sF
dewpoints as far north as southern-to-central Missouri.

Despite ongoing convection across much of Missouri and perhaps
northern Arkansas at the start of the period, modest heating and
increasing low-level moisture during the early afternoon should
result in MUCAPE between 1000 to perhaps 1500 J/kg ahead of the
surface cold front, most-likely across south-central Missouri.
Storms should develop along the front during the early afternoon and
progress east with the front. Forecast wind fields support a couple
of strong tornadoes either within isolated storms or within bowing
segments. As storms grow upscale during the afternoon, the severe
wind threat will increase, especially given the strength of the
low-level flow.

The severe threat should peak during the late afternoon before
beginning an overall weakening trend into the evening hours as the
mid-level low pulls away from the better moisture/instability.

..Marsh/Squitieri.. 04/20/2025

$$