SPC Aug 24, 2026 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1122 AM CDT Mon Aug 24 2026

Valid 241630Z - 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 severe wind
gusts will be possible this afternoon and evening across parts of
the Upper Midwest as well as the central High Plains. Other severe
thunderstorms with mainly a damaging wind threat are possible across
the central Gulf Coast and coastal Carolinas.

...Central Gulf Coast...
Satellite/radar mosaic late this morning shows a cluster of storms
moving south along the MS River. Mostly clear skies will promote
additional heating to the south over the coastal plain, which will
further destabilize the airmass and lead to steepening 0-2 km lapse
rates (in excess of 8 deg C/km) as temperatures warm into the lower
90s deg F. Deep-layer northerly steering flow will favor southward
movement of the thunderstorm cluster and new updraft development on
the leading edge of the cold pool. As this convection likely
continues to develop and become surface-based through the mid
afternoon, there will be a corresponding increase in potential for
scattered wet microbursts (55-65 mph gusts capable of wind damage)
with the stronger cores. This activity will likely push south of
the coast by the early evening.

...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. Widely scattered
thunderstorms are forecast to develop late this afternoon into the
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 gusts 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 the mid levels should support
initial supercells capable of large hail, prior to a clustering of
these southeastward-moving thunderstorms. The risk for scattered
severe gusts may linger through mid/late evening across the central
High Plains before increasing MLCIN encourages gradual weakening.

...Coastal Carolinas...
A larger-scale low/troughing centered over the St. Lawrence Valley
will maintain cyclonic mid to high-level flow over the region this
afternoon. The 12 UTC Charleston, SC and Newport, NC raobs showed a
very unstable airmass in place to the southeast of a cold front
draped over the Carolinas. Veering and strengthening flow with
height will support deep-layer shear (30-35 kt) favorable for storm
organization. The stronger storms will be capable of a
hail/wind-damage risk this afternoon. See MCD #2112 for short-term
details through early afternoon regarding severe potential.

...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...
Partly cloudy skies will promote some heating and resulting in
weak instability (500-1000 J/kg MLCAPE) by early to mid afternoon.
Forecast soundings show elongated hodographs due to a 100+ kt upper
speed max overhead. A few of the stronger thunderstorms may be
capable of a localized hail/wind risk for a few hours before this
marginal threat subsides by early evening.

..Smith/Chalmers.. 08/24/2026


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SPC Aug 24, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


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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SPC Aug 24, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1259 AM CDT Mon Aug 24 2026

Valid 241200Z - 251200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST...CENTRAL HIGH PLAINS...MIDDLE GULF
COAST AND COASTAL CAROLINAS...

...SUMMARY...
Severe thunderstorms capable of large hail and damaging wind gusts
will be possible mainly this afternoon and evening across the
Dakotas and northwest Minnesota as well as the central High Plains.
Other severe storms may focus across the lower Mississippi Valley
and middle Gulf Coast, as well as the coastal Carolinas.

...Dakotas/Upper Midwest to central High Plains...
An eastward-moving shortwave trough will emerge from the Canadian
Rockies and move across the Canadian prairies through tonight, with
a belt of moderately strong flow aloft and multiple MCVs influencing
the Dakotas to Minnesota. Residual early day convection and
lingering cloud cover will be complicating factors as far as the
later-day forecast scenario.

That said, at least widely scattered thunderstorms should develop
and increase by late afternoon within a moist/unstable air mass near
the eastward-moving front and weak surface wave across the
east-central Dakotas and/or cross the international border and move
southeastward into the region. Deep-layer wind profiles would be
conducive to some supercells and the development of
east/southeastward-moving clusters by evening, with large hail and
damaging winds possible.

More removed from the stronger cyclonic flow aloft, additional
higher-based storms are expected by late afternoon and early evening
south-southwestward across the Black Hills/western Nebraska in
vicinity of the front and preceding trough. Sufficient
strength/veering of winds with height should support some initial
supercells capable of hail, prior to a clustering of these
southeastward-moving storms, with wind damage being a possibility
through mid/late evening across the central High Plains.

...Coastal Carolinas...
The region will be influenced by moderately strong cyclonic flow
aloft, with a moist and moderate-to-strongly unstable environment
along the coastal plain to the east of a stationary/slow-moving
front. The degree of buoyancy and upwards of 35-40 kt effective
shear could support some initial supercells with hail this
afternoon, although damaging winds should be the most prevalent
concern as storms become more numerous. Severe potential should tend
to wane by around sunset.

...Lower Mississippi Valley/Middle Gulf Coast...
Widely scattered elevated convection has developed early in the
overnight across the Ozarks, and this regime may increase and
probably shift south-southeastward today, potentially becoming
surface based into the afternoon, influenced by cold pool
development. It seems plausible that an upscale-growing/forward
propagating cluster could gradually evolve during the day, with
damaging wind potential increasing across the ArkLaMiss
south-southeastward toward the Gulf Coast.

...Northern Great Basin/central Rockies...
Scattered high-based thunderstorms are expected to develop this
afternoon amid classic inverted-V profiles. Since these storms will
develop along the periphery of stronger flow aloft, some
organization is possible. Multiple dry microbursts may occur, some
of which may pose a severe gust threat.

...Maine...
By late morning into early afternoon, partially clearing skies will
encourage surface temperatures to rise into the 70s F, resulting in
marginal instability (e.g. a few hundred J/kg MLCAPE) given
relatively poor mid-level lapse rates. Nonetheless, a southerly
mid-to upper-level jet streak will overspread northern New England
during the afternoon, resulting in highly elongated hodographs and
30-40 kt of effective shear. As such, any storms that can develop
and become sustained should become organized multicells capable of
supporting a few damaging gusts and possibly some hail.

..Guyer/Weinman.. 08/24/2026


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SPC Aug 23, 2026 2000 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 2000Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0259 PM CDT Sun Aug 23 2026

Valid 232000Z - 241200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN ROCKIES/PLAINS AND GREAT BASIN...

...SUMMARY...
Thunderstorms capable of producing large hail and severe wind gusts
are forecast across parts of the northern Rockies/Plains this
afternoon and evening. Other thunderstorms with mainly a severe
wind threat are probable over portions of the northern Great Basin.

...20z Update...

...Northern Rockies/Plains and Great Basin...
Subtle adjustments were made to the existing Marginal/Slight risk
areas based on ongoing convective trends. Recent CAM/TLE guidance
suggests that upscale growth of convection into one or more linear
clusters may result in localized corridors of greater
damaging/severe wind coverage across portions of northern Utah and
central Montana. The evolution of this scenario remains somewhat
uncertain, however, which precludes the addition of 30% wind
probabilities at this time. See MCDs 2099, 2100, and 2101 for
additional short-term details.

...Coastal Carolinas...
Recent mesoanalysis and observational data depict modestly elongated
hodographs and effective shear around 35 kts in place across
portions of the Coastal Carolinas. Despite poor mid-level lapse
rates, this may allow for the occurrence of isolated, marginally
severe hail with the most robust updraft cores. Thus, a targeted 5%
hail probability area was included with this update, which is
similarly supported by AI/ML guidance and recent CAM solutions.

Elsewhere, the forecast remains largely on track, with only minor
adjustments made based on the latest forecast and observational
trends. See the discussion below for additional details.

..Chalmers/Moore.. 08/23/2026

.PREV DISCUSSION... /ISSUED 1135 AM CDT Sun Aug 23 2026/

...Great Basin into the Northern Rockies/High Plains...
Water-vapor imagery this morning shows an eastward-migrating
shortwave trough over the Pacific Northwest. A belt of 40-50 kt of
west-southwesterly mid-level flow will overspread the northern
Rockies and adjacent High Plains of central/eastern MT by this
afternoon. Heating along with ascent attendant to the disturbance
will favor initial storm development over the higher terrain over
southwest/western MT. Steepening lapse rates over the High Plains
will favor the potential for scattered severe gusts as thunderstorms
move/develop over the plains during the late afternoon and evening.
A mix of multicells and supercells may yield a risk for severe hail
early before upscale growth into linear clusters (60-80 mph gusts)
likely evolves during the evening.

A somewhat separate area of convection should develop this afternoon
across parts of the northern Great Basin and Upper Snake Valley.
While mid-level flow will be somewhat weaker across this region
compared to locations farther north, the presence of generally 50s
surface dewpoints across northern UT and vicinity suggests that
sufficient low-level moisture exists to support robust updrafts.
Very steep lapse rates will favor ample evaporative cooling in the
stronger downdrafts. Scattered severe gusts (60-80 mph) are
possible with the stronger thunderstorm cores and outflow.

...Northern/Central Plains...
Morning surface analysis places a moisture plume (lower to mid 60s
deg F dewpoints) extending from the TX-OK Panhandles
north-northwestward through eastern CO/NE Panhandle and into the
Black Hills vicinity. It is within this corridor moderate to strong
instability is forecast by mid-late afternoon along/east of a lee
surface trough. At least isolated thunderstorms should develop by
peak afternoon heating across these areas, with west-northwesterly
flow strengthening with height through mid/upper levels. Around
35-45 kt of deep-layer shear will support supercells and associated
threat for large hail from northeast CO northward into the western
Dakotas.

Farther south, high-based convection is forecast to slowly
spread/move east of the Raton Mesa into the TX-OK Panhandles during
the early evening. Very steep lapse rates and inverted-V profiles
will favor evaporative cooling and an isolated threat for severe
gusts with the stronger downdrafts and outflow surges.

...Northeast...
Midday satellite imagery shows an upper trough/low over Ontario with
a series of embedded shortwave impulses rotating through its base.
A lead disturbance over the Lower Great Lakes will continue to
rotate northeastward across the western portion of the Northeast and
influence scattered thunderstorm development this afternoon.
Heating of an adequately moist airmass but relatively meager
mid-level lapse rate environment will result in weak buoyancy
developing through mid afternoon as convection deepens. Around
30-35 kt of deep-layer shear will support some updraft organization
mainly in the form of bands of storms. An isolated risk for strong
to locally severe gusts is expected across much of this region this
afternoon. Towards early evening, an upstream impulse will approach
the Lake Erie vicinity with some uptick in storm coverage and
perhaps a lingering risk for wind damage before this activity
weakens by the mid evening.

...Southeast...
Isolated to scattered thunderstorms will likely develop along/south
of a weak front draped across the lower MS Valley into the Gulf
Coast states, and continuing northeastward into the Carolinas. An
isolated threat for strong to locally severe gusts may result in
pockets of wind damage with the more intense wet microbursts.

...Northeast Oklahoma/Southeast Kansas into the Ozarks...
Some modest increase in isentropic ascent associated with
a south-southwesterly low-level jet, may aid thunderstorm
development late tonight into early Monday morning across parts of
northeast OK/southeast KS into the Ozarks. Instability is forecast
to remain fairly weak (MUCAPE generally less than 1000 J/kg), but
some clustering may occur with a low chance for localized severe
gusts.

...Arizona...
On the western periphery of a mid-level anticyclone centered over
eastern NM, weak southeasterly mid-level flow will remain across
southern/central AZ. Model guidance only depicts weak buoyancy
across much of central and southern AZ, with the exception of
perhaps over far southern AZ. Nonetheless, hot temperatures and a
deeply mixed boundary layer lend some potential for a localized
microburst risk.


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