912
ACUS02 KWNS 010556
SWODY2
SPC AC 010554

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1254 AM CDT Sat Jun 01 2024

Valid 021200Z - 031200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN
AND CENTRAL PLAINS INTO THE UPPER MIDWEST...

...SUMMARY...
Strong to severe thunderstorms are possible from the northern and
central Plains into the Upper Midwest on Sunday.

...Northern/Central Plains into the Upper Midwest...
A fast-moving, low-amplitude shortwave trough is forecast to move
from the Intermountain West through the northern/central Plains and
into the Upper Midwest on Sunday. Lee surface troughing will sharpen
ahead of this shortwave, with cyclogenesis anticipated across the
western Dakotas Sunday morning. This low is then forecast to
progress northeastward across ND and into far northwestern Ontario.
A cold front attendant to this low will push eastward/southeastward
across the northern/central Plains and Upper Midwest. Southern
extent of this front will likely stall in the NE/KS border vicinity,
with secondary cyclogenesis over eastern CO and associated strong
southerly low-level flow limiting its southward progress.

Moisture advection across the Plains is expected to bring low 60s
dewpoints in the Dakotas, with mid 60s across NE and upper 60s
across KS. Cold mid-level temperatures and associated steep
mid-level lapse rates will advect into the region in tandem with the
approaching shortwave. The resulting combination of
low-level moisture, steep mid-level lapse rates, and diurnal heating
will support airmass destabilization and moderate buoyancy ahead of
the cold front. Thunderstorms are expected to develop quickly along
this front during the afternoon, likely beginning across western ND
before spreading southward. Given the linear forcing along the cold
front, quick upscale growth appears likely, although there could be
a minimum in thunderstorm coverage across SD, resulting two distinct
convective lines. The northern line is expected to move quickly
across ND and northern SD and into MN. Large hail is possible early
while development is more cellular, with damaging gusts more likely
thereafter. Moderate to strong southerly flow will likely precede
this line, supporting looping low-level hodographs and at least some
limited potential for a tornado or two within the line.

Greater buoyancy is anticipated with the southern line, as well as
higher storm bases, contributing to the potential for stronger
outflow and an increased potential for a forward-propagating
convective line. Some gusts over 65 kt appear possible as the line
progresses quickly eastward across NE. Thunderstorm intensity should
gradually diminish with eastern extent given less low-level moisture
and nocturnal stabilization.

...KS into Southwest TX and Western/Central OK...
A convective line may be ongoing across western/central OK early
Sunday morning, but predictability of the intensity and location of
the line is low, owing to the mesoscale processes that will dominant
its development. There is some chance the line continues
southeastward into TX, with potential to reintensify as it
encounters the moist and destabilizing airmass. However, limited
predictability precludes delineating any probabilities across
central/east TX.

Isolated thunderstorms are also possible during the afternoon
across the southern High Plains along the dryline. Large-scale
forcing for ascent will nebulous and mid-level temperatures will be
warm, limiting overall coverage. Even so, strong heating and
moderate low-level convergence along the dryline could still result
in convective initiation. Any storms that do develop could produce
large hail and damaging gusts.

...OH/TN Valleys into the Southeast...
Farther east, northeastward progression of a weakening shortwave
trough and associated surface low will aid in thunderstorm
development across the OH Valley. Airmass destabilization is also
anticipated across much of the Southeast, with afternoon
thunderstorm development likely, particularly along the Gulf Coast
where the sea breeze will focus development. Weak shear should
mitigate overall storm strength in both areas.

..Mosier.. 06/01/2024

$$