052
ACUS01 KWNS 100049
SWODY1
SPC AC 100048

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 PM CDT Wed Jul 09 2025

Valid 100100Z - 101200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS
PARTS OF THE EASTERN DAKOTAS...CENTRAL AND EASTERN
NEBRASKA...SOUTHWESTERN MINNESOTA AND WESTERN IOWA...

...SUMMARY...
Scattered strong thunderstorm development, perhaps including an
organizing cluster or two, remains possible tonight and could pose a
risk for severe wind and hail across the northern Great Plains/Mid
Missouri Valley vicinity.

...01Z Update...

...Northern Great Plains/Mid Missouri Valley...
Scattered, generally high-based strong thunderstorm development,
which initiated within lee surface troughing across the northern
high plains, has slowly propagated into the central Dakotas and
Nebraska, in the presence of at least modestly sheared, but weak
(10-20 kt) westerly deep-layer mean flow.  Seasonably moist
boundary-layer air (including 70+ F surface dew points) along a
baroclinic zone across the central into eastern Dakotas and Nebraska
is contributing to a corridor of moderate to strong potential
instability, beneath steep lower/mid-tropospheric lapse rates.
However, the thermodynamic profiles include very warm elevated
mixed-layer air (including 700 mb temperatures of +12 to 14 C),
which will contribute to increasingly substantive inhibition with
the onset of boundary-layer cooling.

It remains unclear how long forcing for ascent will be sufficient to
maintain ongoing convective development this evening, but a
nocturnally strengthening low-level jet, aided by boundary-layer
decoupling, is forecast across western Kansas toward the mid
Missouri Valley through 03-06Z.  This would seem to offer better
potential for the maintenance and perhaps intensification of the
cluster now propagating south/southeast of Valentine NE.  Otherwise,
warm advection aided by the low-level jet could focus renewed
thunderstorm initiation and upscale growth on the eastern periphery
of the more strongly capping elevated mixed-layer air, across the
southeastern South Dakota/eastern Nebraska/western Iowa vicinity
later tonight.

..Kerr.. 07/10/2025

$$