ACUS01 KWNS 231244
SWODY1
SPC AC 231242

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Wed Apr 23 2025

Valid 231300Z - 241200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN/CENTRAL PLAINS...

...SUMMARY...
Scattered strong to severe thunderstorms are forecast over parts of
the southern/central Plains today and tonight, with large hail and
damaging winds possible.

...Southern/Central Plains...
Convective clusters have persisted through the early morning hours
across parts of TX, aided by modest low-level warm/moist advection.
This activity has generally weakened, but it could still pose some
threat for mainly isolated gusty winds towards the ArkLaTex and
Upper TX Coast. In its wake, a convectively overturned airmass will
exist today over much of central TX, while modified low-level
moisture will once again advect west-northwestward over the
southern/central High Plains. A similar convective scenario to
yesterday remains apparent, with generally modest west-southwesterly
mid-level flow present over much of the southern/central Plains.
Multiple low-amplitude perturbations should advance
east-northeastward in this regime across the central CONUS through
the period. At the surface, a front draped southwest to northeast
over the central Plains and a dryline extending southward over the
southern Plains should both serve as foci for convective initiation
later today.

Steep mid-level lapse rates are once again expected to be in place
across the warm sector. Diurnal heating of a modestly moist
low-level airmass in combination with these steep lapse rates should
aid in the development of moderate to locally strong instability by
mid afternoon. Weak low-level winds veering and gradually
strengthening with height through mid/upper levels will foster
around 25-35 kt of effective bulk shear, which should be adequate
for modest convective organization. Current expectations are for
isolated to scattered thunderstorms to once again develop along both
the front and dryline by mid to late afternoon. A mix of multicells
and slow-moving supercells is anticipated, with associated threats
for both severe/damaging winds and large hail.

The Slight Risk has been expanded northeastward across KS and into
far southern NE based on latest guidance trends showing greater
coverage of potentially intense thunderstorms this afternoon/evening
along and near the front. The potential for thunderstorms to grow
upscale into one or more clusters this evening remains uncertain
owing to weak large-scale forcing for ascent. Even so, a
strengthening low-level jet overnight may aid in convective
longevity and a continued threat for isolated damaging winds.

...Upper Midwest...
Daytime heating along with a plume of modest low-level moisture
along/near a surface front should aid in the development of isolated
to scattered thunderstorms this afternoon. Steep lapse rates aloft
and favorable deep-layer shear may support isolated hail and gusty
winds with this activity through the early evening, before it
eventually weakens with the loss of daytime heating.

...Southeast...
Isolated instances of marginally severe hail and/or damaging winds
may occur with convection forecast to increase in coverage this
afternoon across parts of the Southeast along/south of a remnant
surface front. Generally modest flow aloft and weak deep-layer shear
should keep the overall severe threat fairly isolated/marginal.

..Gleason/Broyles.. 04/23/2025

$$
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ACUS01 KWNS 241231
SWODY1
SPC AC 241230

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0730 AM CDT Thu Apr 24 2025

Valid 241300Z - 251200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN/CENTRAL PLAINS...

...SUMMARY...
Isolated to scattered severe thunderstorms are possible today and
tonight across parts of the southern/central Plains. Large to very
large hail and severe wind gusts may occur with this activity.

...Southern/Central Plains...
Aided by modest low-level warm/moist advection, an expansive but
slow-moving MCS has persisted through the early-morning hours across south-central OK into north-central TX. Isolated damaging winds may
occur with this activity through the morning as it spreads
southeastward across a moist but weakly unstable airmass. The
potential for the MCS to either restrengthen, or for additional
robust convection to develop along its outflow this afternoon
remains rather uncertain. Even so, the downstream airmass should
gradually destabilize through the day, and both damaging winds and
hail may occur with the MCS if it can maintain surface-based inflow.
Have therefore expanded the Marginal Risk eastward towards the
ArkLaTex and east TX to account for this scenario. Greater severe
probabilities may need to be considered if it becomes clear that the
MCS will produce swaths of damaging winds later today.

Otherwise, another day of isolated to widely scattered severe
thunderstorms is forecast across the southern/central High Plains. A
broad zone of modestly enhanced west-southwesterly mid-flow will
persist across these regions though the period, with multiple
convectively augmented vorticity maxima present. A front extending northeastward across KS from a weak low in far southeast CO, along
with a dryline extending southward from the low across the southern
High Plains, should once again help focus convective initiation
later today. Even with multiple prior days of convection occurring,
the northeastward advection of an EML over the Southwest will
provide steepened mid-level lapse rates across the warm sector.
Daytime heating of the moist low-level airmass, in concert with the
steep lapse rates aloft, will support at least moderate instability
along/south of the convectively reinforced front and east of the
dryline by mid afternoon. While deep-layer shear should remain
fairly modest, it will still be sufficient for organized updrafts.

Current expectations are for isolated to widely scattered
thunderstorms to form from parts of eastern CO (in a weak low-level
upslope flow regime) into the OK/TX Panhandles and west TX
along/east of the dryline. Similar to prior days, a mixed mode of
supercells and multicells should occur, with large to very large
hail possible with any slow-moving supercells. Severe/damaging winds
may occur with any clusters that can develop through the evening,
although this threat may tend to remain fairly isolated. A tornado
or two also appears possible, especially with any sustained
supercell this evening near the front/dryline intersection across
southwest KS into the eastern OK/TX Panhandle vicinity. Based on
extensive convection that occurred overnight across western KS, the
northern extent of the Slight Risk has been adjusted some across the
central Plains.

...Southeast Nebraska into Iowa...
A convectively augmented/low-amplitude shortwave trough will move
northeastward from parts of southeast NE into IA and vicinity today.
Although low-level moisture should remain fairly limited, it is
forecast to gradually increase along/south of a front by this
afternoon. Any thunderstorms that can develop and spread
northeastward could pose an isolated hail/wind threat given
sufficient deep-layer shear for updraft organization.

..Gleason/Broyles.. 04/24/2025

$$
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