SPC Jun 3, 2025 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0736 AM CDT Tue Jun 03 2025

Valid 031300Z - 041200Z

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

...SUMMARY...
Scattered severe thunderstorms are possible from the southern Great
Plains to the Midwest. Damaging winds and large hail are the primary
concerns.

...Central/Southern Plains into the Midwest...
Recent satellite imagery shows a well-defined shortwave trough over
eastern CO/northeastern NM, embedded within larger upper troughing
that extends over much of the western and central CONUS. An
extensive area of showers and thunderstorms (i.e. from the TX Hill
Country into IA and MN) is ongoing ahead of this shortwave trough
and its associated cold front. These showers and thunderstorms will
likely continue eastward/northeastward throughout the day, which
could limit diurnal heating along the frontal zone, particularly
from the IL/IA border vicinity northward. This limited heating will
temper the overall buoyancy in those areas, keeping the severe risk
isolated despite the presence of stronger deep-layer shear than
areas farther south.

Moderate diurnal heating appears likely ahead of the cold front 
from the IA/MO/IL border intersection vicinity southwestward across
MO and into eastern OK and KS. However, the amount of precipitation
currently ongoing in this region and upstream does introduce some
doubt to whether or not highs in the mid 80s will be realized. Even
if temperatures stay in the upper 70s/low 80s, abundant low-level
moisture coupled with relatively modest mid-level temperatures
should still result in an uncapped airmass ahead of the front during
the early afternoon. Given the line-parallel orientation of the
deep-layer shear across this region, expectation is for a
predominantly linear storm mode, with occasional bowing segments
capable of producing damaging gusts. 

The strongest heating ahead of the cold front is anticipated from
western OK south into the TX Hill Country. Here, afternoon
temperatures will likely reach the low 90s amid dewpoints in the
upper 60s (perhaps even the low 70s). These surface conditions will
help support strong to very strong buoyancy ahead of the front, with
MLCAPE over 2500 J/kg for much of this region by 21Z. Robust
thunderstorms are expected to develop when the front interacts with
this buoyancy, with potential for some pre-frontal development
within areas of low-level confluence as well. An initially more
cellular mode is likely, and vertical shear is forecast to be strong
enough to support supercells. Large hail will be the primary risk
with these storms, but some low tornado potential exists as well,
particularly near a low expected to be over the southwest
OK/northwest TX region during the afternoon. Given the frontal
forcing and widespread coverage, a quick transition to a linear mode
appears likely, with damaging gusts becoming the primary severe
risk. The deep-shear vector here should be more orthogonal to the
line than areas farther north, fostering the potential for a more
forward-propagating convective line across central OK and
north-central/central TX from the late afternoon through the
evening. Strong to occasionally severe thunderstorms should continue
along the front as it moves into TX Hill Country tonight.

..Mosier/Broyles.. 06/03/2025

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