Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0730 AM CDT Mon Aug 24 2026
Valid 241300Z - 251200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS/UPPER MIDWEST...CENTRAL HIGH PLAINS...LOWER
MISSISSIPPI VALLEY/CENTRAL GULF COAST...AND COASTAL CAROLINAS...
...SUMMARY...
Severe thunderstorms capable of producing large hail and damaging
winds will be possible this afternoon and evening across the Dakotas
and northwest Minnesota as well as the central High Plains. Other
severe thunderstorms with mainly a damaging wind threat may focus
across the lower Mississippi Valley and coastal Carolinas.
...Dakotas/Upper Midwest into the Central High Plains...
A mid-level shortwave trough over Alberta/Saskatchewan will move
eastward across the Canadian prairie provinces through tonight, with
a belt of moderately strong flow aloft and multiple MCVs influencing
the northern Plains to Upper Midwest. Residual/ongoing convection
this morning and lingering cloud cover will be complicating factors
for thunderstorm development and evolution later today.
Even so, widely scattered thunderstorms should develop by late
afternoon or early evening within a moist/unstable airmass near an
eastward-moving front and weak surface wave across central/eastern
ND. Other convection may initiate and then move southeastward from
south-central Canada. Around 35-45 kt of deep-layer shear will
support supercells initially with a large hail threat. The
development of east/southeastward-moving clusters should eventually
occur this evening, with scattered severe/damaging winds possible.
Farther south and a bit more removed from the stronger cyclonic flow
aloft, additional high-based thunderstorms are expected to form by
late afternoon/early evening across the Black Hills/western NE in
the vicinity of the surface front. Strengthening and sufficient
veering of winds with height through mid levels should support
initial supercells capable of large hail, prior to a clustering of
these southeastward-moving thunderstorms. Scattered severe/damaging
winds may occur with this activity through mid/late evening across
the central High Plains before increasing MLCIN encourages gradual
weakening.
...Coastal Carolinas...
The Carolinas will be influenced by modestly enhanced cyclonic flow
aloft today, with a moist and moderately to strongly unstable
environment forecast along the coastal plain to the east of a
slow-moving front. This favorable instability and around 30-40 kt of
effective bulk shear should support initial supercells with some
hail risk this afternoon. However, scattered damaging winds will
probably become the primary concern as thunderstorms increase in
coverage. Severe potential should tend to wane by early evening as
convection moves offshore and/or weakens with the loss of daytime
heating.
...Lower Mississippi Valley/Central Gulf Coast...
Widely scattered elevated convection has developed this morning from
southeast KS into AR in a low-level warm advection regime. This
convection will shift south-southeastward today, potentially
becoming surface based into the afternoon as diurnal heating
supports downstream destabilization of a rather moist low-level
airmass. Even though deep-layer shear will remain weak, an
upscale-growing/forward-propagating cluster may evolve during the
afternoon, with scattered damaging wind potential increasing across
the ArkLaMiss south-southeastward toward the central Gulf Coast.
...Northern Great Basin into the Central Rockies...
Isolated to scattered high-based thunderstorms are expected to
develop this afternoon across parts of the northern Great Basin into
the central Rockies amid steepening low-level lapse rates with a
very well-mixed boundary layer. Since this convection will develop
along the periphery of stronger flow aloft, modest organization is
possible even though low-level moisture and related instability
should remain weak. Occasional dry microbursts may occur, some of
which could pose an isolated threat for severe gusts.
...Maine...
Across northern ME, partially clearing skies this afternoon should
encourage surface temperatures to rise into the 70s, resulting in
weak instability (up to 250-500 J/kg MLCAPE) given relatively poor
mid-level lapse rates. Even so, a southerly mid/upper-level jet will
overspread northern New England during the afternoon, resulting in
highly elongated hodographs and 30-40 kt of effective bulk shear.
Any thunderstorms that can develop and be sustained could become
organized multicells capable of producing isolated damaging gusts
and perhaps marginally severe hail.
..Gleason/Broyles.. 08/24/2026
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