Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0255 PM CDT Tue Jun 03 2025
Valid 032000Z - 041200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ROM 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.
...20z Update...
...Northern Missouri...
The primary forecast update pertains to the organizing/intensifying
convective line entering western MO (as of 19 UTC). Downstream of
this line, satellite trends show dissipating cirrus with increasing
low/mid-level cumulus associated with a northward advection of
low-level moisture and increasing diurnal heating. Consequently, it
is becoming increasingly probable that downstream destabilization
will be sufficient and timely enough to maintain the strengthening
line as it moves into northern MO and perhaps into southeast IA
later this evening. Recent CAM guidance appears to be capturing this
trend well and show a consistent severe wind signal through this
corridor. Recent VWP observations from KEAX show sufficient
low-level shear within the recovering air mass (driven by
strengthening low-level warm advection) to support a threat of
embedded circulations/brief tornadoes within the line. As such, 5%
tornado probabilities have been introduced.
...Southern Plains...
Thunderstorm coverage is beginning to increase from southern KS into
central OK/northern TX as temperatures warm into the mid 80s with
eroding inhibition. This trend is expected to continue as a cold
front continues to push east into a moist/unstable air mass. The
KTLX VWP continues to sample sufficient deep-layer shear for
organized convection, including the potential for a supercell or two
ahead of the primary convective line. While severe hail/wind will be
possible with pre-line discrete cells, the primary severe risk will
likely manifest with the developing convective line later this
afternoon and evening.
..Moore.. 06/03/2025
.PREV DISCUSSION... /ISSUED 1127 AM CDT Tue Jun 03 2025/
...Central/Southern Plains into the Midwest...
Water-vapor imagery late this morning shows a mid-level shortwave
trough over the central Great Plains, embedded within larger upper
troughing centered over MT/WY and the Dakotas that extends over much
of the north-central U.S. A cold front extends from the western
Great Lakes southwestward to a weak low near the OK/KS/TX Panhandle
region. An extensive area of showers and thunderstorms exists from
KS eastward into the mid MS Valley near the frontal zone.
A low-predictability forecast scenario regarding specific details of
storm evolution is expected this afternoon into the evening. A
relatively weak capping inversion was sampled by the 12 UTC Norman,
OK and Fort Worth/Midland, TX raobs (9 to 10 deg C at 700 mb) over
the southern Great Plains. Heating in wake of morning convection
and related cloud debris will promote a very unstable boundary layer
by early to mid afternoon. Expecting a diurnal increase in
low-level moisture coincident with the evapotranspiration cycle and
lowest 100-mb mean mixing ratios increasing from 14-15 to 16-17 g/kg
(translated to surface dewpoints rising from 68-70 to 72-76 deg F).
Forecast soundings show 2500-3500 J/kg MLCAPE from southwest MO into
central TX. The 12 UTC model run of the NAM appears to be an
unrealistic outlier solution showing enhanced low-level shear across
OK during the afternoon. As convective inhibition erodes across the
southern Great Plains east of a dryline/cold front and south of
reinforced outflow draped across southern KS into northern MO,
expecting scattered to numerous thunderstorms to develop during the
afternoon into the evening period. Severe gusts and large hail
appear to be the primary severe hazards. Strong to occasionally
severe thunderstorms should continue along the front as it moves
into TX Hill Country tonight. An elongated corridor of low-tornado
potential will be maintained this outlook update from the southern
Great Plains northeastward through the lower MO Valley and into the
western Great Lakes. A belt of 40-kt 2 km southwesterly flow will
be maintained across western into northern MO and spatially
overlapping outflow in the lower MO Valley. Limited heating will
temper the overall buoyancy across the northern half of MO into IA,
likely tempering the overall severe risk. Additionally, with the
line-parallel orientation of the deep-layer shear across this
region, the expectation is for a predominantly linear storm mode,
with occasional bowing segments capable of producing damaging gusts.
Read more CHECK UPDATE ZOOM GRAPHIC
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