ACUS01 KWNS 211938
SWODY1
SPC AC 211937

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0237 PM CDT Sat Mar 21 2026

Valid 212000Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
SOUTHERN APPALACHIANS TO THE CAROLINAS...

CORRECTED FOR GEOGRAPHIC AREA HEADLINE

...SUMMARY...
Isolated strong to severe thunderstorms may produce marginally
severe hail and damaging winds this afternoon and evening from the
southern Appalachians into the Carolinas.

...20Z Update...
The previous forecast (see below), remains on track. Please see
Mesoscale Discussion 283 for short-term information on the severe
threat across portions of the southern Appalachians.

..Squitieri.. 03/21/2026

.PREV DISCUSSION... /ISSUED 1129 AM CDT Sat Mar 21 2026/

...Southern Appalachians into the Carolinas...
Recent satellite imagery shows a somewhat subtle and broad shortwave
trough progressing southeastward through the MS Valley, along the
far northeast periphery of the upper ridging covering much of the
Southwest and southern Plains. Limited low-level moisture precedes
this wave, with recent surface analysis sampling dewpoints ranging
from the upper 50s across much of AL to the mid 40s across much of
the Carolinas. Modest low-level moisture advection is anticipated
today ahead of this wave. However, this advection will be countered
by diurnal mixing, and the general expectation is for dewpoints to
be in the upper 40s/low 50s from eastern TN into the Carolinas as
the wave moves in the area this afternoon. Even with this limited
low-level moisture, cool mid-level temperatures and associated steep
mid-level lapse rates will support weak buoyancy and the potential
for isolated to widely scattered thunderstorms this afternoon and
early evening.

Large-scale ascent will be modest, supporting an initially more
cellular, loosely organized storm mode. This region will be on the
southern periphery of the stronger mid-level flow, likely resulting
in sufficient shear for organization within any deeper, more
persistent updrafts. As such, updrafts are expected to gradually
intensify as they move into the western and central Carolinas.
Marginally severe hail is possible with the strongest cores. A trend
towards a more linear/line segment mode is expected with time, and
persistent steep low-level lapse rates may support occasional strong
to damaging downdraft winds as well. The onset of nocturnal
boundary-layer stabilization should result in a decreasing severe
threat as the storms move into the coastal Carolinas.

$$

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ACUS01 KWNS 030810
SWODY1
SPC AC 030808

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0308 AM CDT Fri Apr 03 2026

Valid 031200Z - 041200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
MISSOURI AND SOUTHERN IOWA...

CORRECTED FOR CORRECTED CATEGORICAL GRAPHIC

...SUMMARY...
Storms are expected to evolve into an extensive line by Friday
evening from Iowa to Oklahoma and northwest Texas, with the primary
threats of large hail and damaging winds. A few tornadoes and
isolated very large hail will be possible from northern Missouri
into southern Iowa with any sustained supercells.

A midlevel trough, emanating from a previous TPV, will move across
the northern US today and tonight. This feature will maintain a
modest surface cyclone that will progress northeastward from central
Kansas to southern Wisconsin by Saturday morning. As the surface low
lifts northeast, a west-east orientate warm front will push
northward toward Lower Michigan.

... Northern Missouri and Southern Iowa ...

As the surface cyclone lifts northeast in response to increasing
pressure falls in advance of the midlevel trough, southerly winds
will draw low-level moisture northward, with low-to-mid 60Fs
dewpoints possible along and south of the aforementioned warm front.
Residual steep mid-level lapse rates and modest insolation will
contribute to MLCAPE values up to 2000 J/kg (and MUCAPE values
approach 3000 J/kg). Despite the low-level jet weakening through the
day, deep-layer shear will be sufficient for supercells along and
south of the warm front and east of the Pacific cold front/dryline.
However, given persistent warm-air advection/isentropic ascent
associated with the advancing warm front, concerns abound regarding
the number of storms, storm interactions, and an overall messy storm
mode evolution.

If a more discrete mode emerges, the overall kinematic wind field
would support sustained supercells and an increased tornado threat
along both the Pacific Front/dryline and the northward moving warm
front. Very large hail would also be possible. If a more linear mode
emerges, the primary severe hazard would focus more on strong winds
and a QLCS tornado threat. Of note, even with a more linear mode,
uncertainty in the coverage of potential strong convective winds is
low owing to a weakening low-level jet and storm interactions. The
Level 3/Enhanced was kept at this time, but the need for a
wind-driven Level 3/Enhanced will be revisited in subsequent
forecasts.

... Central Illinois east into Ohio and north into Lower Michigan
...

Thunderstorms will be possible along the northward moving warm front
during the afternoon on Friday. Although there is uncertainty
regarding the number/coverage of storms, the overall thermodynamic
and kinematic fields would support the potential for hail and wind
along and north of the warm front. Across the western portions of
this area, a brief tornado threat would exist as any discrete
supercells traverse through the warm frontal zone.

... Southeast Kansas/Southwest Missouri southwest toward Northwest
Texas...

Thunderstorms will develop southward from northern Missouri into
Oklahoma during the afternoon as the Pacific cold front/dryline
pushes east into an increasingly unstable airmass. At the same time,
additional thunderstorms are likely to develop across Northwest
Texas and southwest Oklahoma in association with a subtle
perturbation within the subtropical jet. Forecast wind fields
indicate low-level flow will be weaker here than areas farther north
and east, and have pronounced weakness in the 3-6 km AGL range. The
combination of this wind field and the widespread nature of the
convection would lend itself to large hail and damaging winds as the
main severe hazards, although a tornado cannot be ruled out with any
discrete storm or along the leading edge of any organized linear
segments.

... Southwest Texas ...

Isolated thunderstorms will be possible during the afternoon/evening
along the higher terrain and a surface dryline. Wind fields will
support supercells capable of producing large hail and damaging
winds. However uncertainty regarding overall storm coverage
precludes a categorical upgrade to Level 2/Slight Risk.

..Marsh/Chalmers.. 04/03/2026

$$

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ACUS01 KWNS 080111
SWODY1
SPC AC 080109

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0809 PM CDT Tue Apr 07 2026

Valid 080100Z - 081200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

CORRECTED FOR WORDING

...SUMMARY...
Isolated thunderstorms remain possible tonight over the northern and
southern High Plains. Severe thunderstorms are not expected.

...Synopsis...
A mid-level trough continues to progress across the northern
Rockies, providing enough mechanical lift amid cooler temperatures
aloft to support isolated high-based thunderstorms atop a dry
boundary layer. A low-amplitude mid-level impulse will also continue
to traverse the southern Rockies, supporting scattered lightning
flashes given the presence of scant buoyancy. These storms should
gradually diminish through the evening as boundary-layer
stabilization from nocturnal cooling takes place.

..Squitieri.. 04/08/2026

$$

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ACUS01 KWNS 110123
SWODY1
SPC AC 110121

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0821 PM CDT Fri Apr 10 2026

Valid 110100Z - 111200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

CORRECTED FOR THUNDER LINE ORIENTATION

...SUMMARY...
Isolated to scattered thunderstorms remain possible during the late
evening hours across parts of the southern Plains and Great Basin;
however, the overall severe risk appears limited.

...Southern Plains...
Latest MRMS imagery depicts steady weakening of convection across
northeast NM and across northern OK with the onset of nocturnal
cooling and expanding convective outflows. While a couple of
stronger storms are noted across far eastern NM and southwest TX,
weak deep-layer wind shear and diminishing buoyancy should favor a
weakening trend heading into the late evening hours.

Additional elevated thunderstorms are anticipated well north of the
stalled surface boundary along the OK/KS border with recent CAM
guidance suggesting multi-cell clusters developing across portions
of central to northeast KS after 03 UTC. The recent 00z DDC RAOB
likely sampled the environment this convection will develop in, and
hints that at least a small hail threat may materialize with
initially discrete cells prior to upscale growth within the first
couple of hours after initiation.

...Great Basin...
Similar to the southern Plains, convective trends have largely shown
signs of weakening over the past hour across central to northern NV
where surface temperatures are quickly cooling into the 60s. The
combination of rain-cooled air/outflows and the onset of nocturnal
cooling should further reduce any remaining mixed-layer buoyancy
(which was already fairly marginal per regional 00z RAOBs).
Consequently, the thermodynamic environment no longer appears
supportive of intense convection, though a strong storm or two may
persist for the next hour as the boundary layer continues to
stabilize.

..Moore.. 04/11/2026

$$

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ACUS01 KWNS 160611
SWODY1
SPC AC 160609

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0109 AM CDT Thu Apr 16 2026

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
ACROSS PARTS OF WESTERN AND CENTRAL NEW YORK INTO SOUTHERN
VERMONT...

CORRECTED FOR TYPOS AND WORDING

...SUMMARY...
A few severe thunderstorms are possible this afternoon in a corridor
across western through central New York (state) and adjacent
southern Vermont.

...Discussion...
A significant mid-level trough and embedded low now digging across
the Pacific Northwest is forecast to split as it continues inland
through this period. One perturbation, perhaps including a
continuing cyclonic circulation, is forecast to turn eastward across
the northern Rockies through the central Canadian/U.S. border area.
Another perturbation is forecast to dig southeastward across the
Great Basin into early Friday. It appears that the larger-scale
evolving troughing will be preceded by a significant cold frontal
surge to the lee of the northern U.S. Rockies, through much of the
northern and central Great Plains by 12Z Friday.

Downstream, initially prominent mid-level ridging centered near the
southern Atlantic Seaboard is forecast to become increasingly
suppressed, as one short wave trough, approaching southwestern
portions of the Great Lakes region early today, turns eastward then southeastward across the lower Great Lakes vicinity into northern
Mid Atlantic. It appears that this will be trailed by another
perturbation, which is forecast to progress east of the Ozark
Plateau through the lower Ohio and Tennessee Valleys, before digging
across the southern Appalachians, downstream of short wave ridging
building across and east of the mid/upper Mississippi Valley.

...Mid South into lower Great Lakes and Northeast...
The primary and trailing short wave troughs advancing to the east of
the Mississippi Valley are forecast to be preceded by the remnants
of overnight convection across parts of the lower Great Lakes, Ohio
Valley, and Mid South at the outset of the period. The impacts of
associated cloud cover and outflow on destabilization within the
warm sector of a broad, but weak, surface low migrating northeast of
the lower Great Lakes during the day remain unclear. However,
various model output, including convection allowing guidance,
suggest that destabilization and strengthening shear along a warm
frontal zone (as it strengthens with differential heating) may
become a focus for organized strong thunderstorm development across
New York state by afternoon. It appears that this may include an
evolving cluster, perhaps preceded by more discrete thunderstorm
activity, in an environment conducive to evolving supercell
structures, with potential to produce severe hail, wind and a risk
for a couple of tornadoes.

Additional thunderstorm activity may eventually develop and
strengthen, accompanied by at least a risk for strong to severe wind
gusts by late afternoon, in a corridor of stronger daytime heating
ahead of a developing cold front spreading into the upper Ohio
Valley/Allegheny and Cumberland Plateau.

Farther west/southwest, there is not a well-defined signal in the
latest model output, but a corridor of differential surface heating
along weakening trailing convective outflow across the Mid South
vicinity could become a focus for supercell development. It
currently appears that this potential could peak across north
central into northeastern Arkansas by late this afternoon, aided by
moderate boundary-layer destabilization and stronger mid-level
forcing for ascent associated with a cyclonic vorticity center
migrating across the region.

...Southern Great Plains...
Moderate to strong potential instability is forecast to develop
beneath steep lapse rates, along and east of a dryline which likely
will be retreating westward across the high plains by early this
evening. While this will be conditionally supportive of severe
thunderstorm development, forcing to support initiation of sustained thunderstorms remains unclear, aside from, perhaps, the higher
terrain near/east of the Texas Big Bend. Beneath moderate to strong southwesterly mid/upper flow, this could include an isolated
supercell or two which could propagate across the Rio Grande River,
before weakening in the presence of increasing inhibition this
evening.

..Kerr/Lyons.. 04/16/2026

$$

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ACUS01 KWNS 171705
SWODY1
SPC AC 171703

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
1203 PM CDT Fri Apr 17 2026

Valid 171630Z - 181200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM FAR
NORTHWEST OKLAHOMA THROUGH CENTRAL AND EASTERN KANSAS INTO
WEST-CENTRAL MISSOURI...

CORRECTED FOR ORIENTATION OF THE 45% HAIL PROBABILITIES

...SUMMARY...
Numerous severe thunderstorms are likely this afternoon into tonight
across parts of the Upper Midwest southward across the lower
Missouri Valley and central/southern Great Plains. Initially this
may be accompanied by a risk for large to giant hail and a few
strong tornadoes, before severe wind gusts of 60 to 90 mph become
the most prominent hazard by this evening.

...Synopsis...
Recent surface analysis places a low over south-central MN, with a
cold front extending southwestward to another low over central KS. A
warm front also extends southwestward from the MN low through far
southwest MN and far northern IL into central IN. This warm front is
demarcated well by the 56 deg F isodrosotherm. Farther south, a
dryline extends from the triple point KS low back southwestward
through the TX Panhandle and into far southeast NM. A broad, moist
warm sector exists to the east of the cold front and dryline,
characterized largely by dewpoints in the low to mid 60s.

A well-defined shortwave trough is apparent on satellite imagery,
extending from southern Saskatchewan back southwestward into the
eastern Great Basin. This wave is forecast to continue eastward,
with a attendant increase in the mid-level flow across much of the
Plains and Upper/Mid MS Valley. The cold front will surge eastward/southeastward in response to this wave as well, interacting
with the warm sector to support numerous strong to severe
thunderstorms from parts of the Upper Midwest southward across the
lower Missouri Valley into southern Plains.

...Upper/Mid MS Valley...
Moderate to strong low-level moisture advection is expected across
the Upper MS Valley today as the surface low mentioned in the
synopsis progresses northeastward, with an attendant northward shift
of the warm front as well. The risk across this region may evolve in
several phases, beginning with the elevated thunderstorms currently
ongoing across northwest WI. This storms will likely continue
northeastward, posing a risk for severe hail and isolated damaging
gusts. Additional development is possible northwest of this activity
along the occluded front, with some hail possible here as well.

Farther south, the northeastward advecting low-level moisture
coupled with strong heating and steep lapse rates will result in a
strongly unstable airmass along and just south of the warm front by
the early afternoon. Storm initiation is anticipated within this
open warm sector by early afternoon, forced by a mix of warm-air
advection, low-level confluence, and subtly increasing large-scale
ascent. This activity should be ahead of the front and initially
discrete. The overall parameter space will be characterized by
strong to very strong buoyancy, moderate deep-layer vertical shear,
and strong low-level helicity. Supercells capable of all hazards are
expected, including large to very large (i.e. 3"+ hail), strong to
intense tornadoes, and severe wind gusts. Storm interactions are
expected to strongly influence the tornado risk, with the initially
discrete mode likely becoming messy quickly.

Farther west, other storms are likely to evolve quickly along the
front, developing into a band of severe thunderstorms that will push
east coincident with the front. Damaging wind gusts will tend to
become more prevalent during the evening with linear storm modes.
Some tornado risk may continue into the evening as maturing bands of
storms yield a threat for bowing segments and embedded mesovortices,
before this activity gradually diminishes late as it moves east into
IN/Lower MI late.

...KS/OK/MO...
A very unstable airmass is expected to develop along and ahead of
the triple point over south-central KS an associated cold front and
dryline. Strong low-level convergence will likely lead to initial
storm development near the triple point. This initial activity will
be supercellular and capable of very large to giant hail (over
3-3.5" in diameter). Highest coverage of very large hail is expected
over from far northwest OK into south-central KS. Strong downdrafts
(60 to 80 mph) are possible as well. With a largely
boundary-parallel orientation to the deep-layer shear, the tornado
risk appears relatively lower. However, given the supercell mode and
potential interactions with outflow, a low-probability tornado risk
remains. A more north-south configuration to the dryline supports a
conditional tornado risk into far northwest TX.

With time, upscale growth and the development of a
forward-propagating MCS is anticipated across central and eastern
KS. Very strong gusts (80+ mph) are possible with this MCS.
Additionally, some QLCS tornado risk will exist within this line as
long as it stays ahead of the surging cold front. The front will
continue sweeping southeastward, with storms along this boundary
yielding a risk for wind/hail.

..Mosier/Chalmers.. 04/17/2026

$$

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ACUS01 KWNS 261342
SWODY1
SPC AC 261341

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0841 AM CDT Sun Apr 26 2026

Valid 261300Z - 271200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ...

CORRECTED FOR SUMMARY WORDING

...SUMMARY...
Scattered severe thunderstorms with large to very large hail,
damaging winds and tornadoes are expected this afternoon through
tonight across parts of the southern/central Plains. A couple of
strong tornadoes and hailstones up to 2-3 inches in diameter are
possible.

...Southern/Central Plains to the Mid Mississippi Valley...
Fairly substantial changes have been made to the outlook based on
latest observational and guidance trends. Namely, the Enhanced Risk
has been expanded into northern OK to account for the potential of
both surface-based supercells this afternoon, and elevated
supercells this evening/tonight. The Slight Risk has been expanded
southward into north-central TX for a somewhat more
conditional/uncertain supercell threat. The eastern extent of severe probabilities have also been expanded in MO to account for a
potential cluster producing severe/damaging winds occurring late
tonight into early Monday morning.

A weak lead mid-level vorticity maximum over the central High Plains
this morning should continue to aid elevated thunderstorm
development across KS through the afternoon. Increasing MUCAPE with
persistent low-level warm/moist advection and steepening mid-level
lapse rates combined with strong deep-layer shear will support
organized updrafts, including the potential for supercells. This
convection will probably tend to remain elevated to the north of a
front as it spreads east-northeastward over the central Plains, but
scattered large hail may occur given the overall favorable
environment. Isolated 2+ inch diameter hail also appears possible
with the strongest cores. Eventually, this activity may pose a
greater threat for damaging winds across eastern KS into western MO
by late afternoon/early evening, if it can become truly surface
based.

A more notable mid-level shortwave trough is expected to eject
northeastward across the Southwest and southern/central High Plans
today, accompanied by a 50-60 kt southwesterly mid-level jet. Weak
lee cyclogenesis is forecast to occur across the southeast
CO/northeast NM vicinity in response, with the surface low
developing into the OK Panhandle and southwest KS by this evening.
Strong to locally extreme instability is once again forecast to
develop to the east of a sharpening dryline across western/central
OK as daytime heating of a moist airmass occurs. There is still a
fair amount of uncertainty with the placement of an effective warm
front by late afternoon/early evening, but current expectations are
for this boundary to be draped somewhere near north-central OK by
peak afternoon heating. The surface triple point may serve as a
focus for convective initiation today, although better large-scale
ascent associated with the mid-level shortwave trough overspreading
the warm sector will be delayed until this evening and past peak
diurnal heating.

Greater than average uncertainty exists regarding the potential for surface-based convective initiation today in OK/north TX. Still, it
appears possible that multiple supercells may develop with gradual
erosion of lingering MLCIN and weak ascent preceding the ejecting
shortwave trough. Any supercells that can root and ingest the ample
low-level moisture will be capable of producing very large hail
(2-3+ inches in diameter) given a overall rather favorable
environment. The tornado potential is less clear through the day,
but a southerly low-level jet will quickly strengthen this evening
and aid curved/elongated hodographs with strong effective SRH. A
somewhat conditional/uncertain threat for a couple of strong
tornadoes remains apparent, especially if any supercells that can
form this afternoon persist into the evening.

Additional, somewhat elevated supercells may form this evening into
tonight along/north of the warm front from northwest OK near the
triple point into KS. This activity will also pose a threat for
large to very large hail. Some guidance suggests a cluster
eventually evolves from this convection across eastern KS into MO
late tonight/early Monday morning. If this occurs, then a greater
threat for severe/damaging winds would exist.

Farther south into TX, the forcing for ascent will remain
weak/nebulous along the dryline. Still, some potential for a few
supercells is apparent across north-central TX where the greatest
heating and minimal MLCIN is forecast to exist. Large to very large
hail should be the main threat with any splitting supercells that
can develop this afternoon along/east of the dryline and be
sustained.

...ArkLaTex/Lower Mississippi Valley/Central Gulf Coast...
A small cluster will continue tracking southeastward this morning
from southern MS to the central Gulf Coast. With sufficient
low-level moisture and instability in place ahead of this
convection, isolated damaging winds may occur. A pair of supercells
across northeast TX have fluctuated in intensity over the past
couple of hours. The potential for additional thunderstorms to form
on the western flank/outflow of this morning convection remains
unclear given weak large-scale forcing and the low-level jet
forecast to weaken further through the morning. If any additional
convection can form, it would pose an isolated severe hail and
damaging wind threat.

..Gleason/Thompson.. 04/26/2026

$$

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ACUS01 KWNS 101758
SWODY1
SPC AC 101756

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
1256 PM CDT Wed Jun 10 2026

Valid 101300Z - 111200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE UPPER/MID MISSISSIPPI VALLEYS AND MIDWEST...

CORRECTED FOR INCORRECT CATEGORICAL GRAPHIC

...SUMMARY...
Scattered to numerous severe thunderstorms with potential for large
hail in excess of two inches in diameter, a few strong tornadoes and
damaging winds with gusts over 75 mph are expected this afternoon
and evening across parts of the Upper Mississippi Valley and
Midwest.

...Mid/Upper MS Valley into the central Plains...
Regional radar imagery shows an ongoing cluster of strong
thunderstorms across southern IA and northern MO, supported by a
residual low-level jet that currently extends from KS/northern OK
into the region. Heating of the very moist airmass downstream will
result in limited convective inhibition and strong to very strong
buoyancy by the early afternoon. Reintensification of the ongoing
cluster is anticipated as it moves within this destabilizing
airmass. Deep-layer shear will be modest but still sufficient for
some organization, and the development of a strong to occasionally
severe bowing line segment appears probable, particularly from
northeast IA into southern WI and northern IL. New updrafts ahead of
the line could also produce hail early in the convective cycle,
while also potentially contributing to updraft augmentation as they
merge into the line. Some isolated hail could result from this
augmentation as well.

Farther north, recent surface analysis placed a triple point low
over northeast SD. An occluded front extends north-northwestward
from this low across eastern ND into central Manitoba, while cold
front extends southward to another low over northeast NE and then
back southwestward across the central Plains. The frontal zone and
triple point low are forecast to progress eastward into the Upper
Midwest, interacting with a diurnally destabilizing airmass to
support thunderstorm development. Ample low-level moisture (i.e.
dewpoints in the upper 60s/low 70s) will support strong buoyancy,
despite modest lapse rates, and moderate deep-layer vertical shear
should be sufficient for updraft organization. As a result, strong
to severe thunderstorms are expected along and just ahead the front,
with large hail as the primary threat. Isolated very large hail to
2" in diameter could occur. Some damaging gusts are possible as
storms transition into bowing line segments over time. There is also
a low-probability for a few brief tornadoes, particularly with any
more cellular development from central into eastern WI from 21 to
00Z.

An additional severe threat will likely materialize this evening in
the wake of the afternoon MCS within the recovered airmass from the
Mid MS Valley westward through the Mid MO Valley into the central
Plains. The impetus for this redevelopment will likely be a complex
combination of low-level convergence along the approaching front,
low-level convergence and warm-air advection along remnant outflow,
and modest large-scale ascent. Development along the front appears
most likely from central IA southwestward into northeast KS, while
development along the outflow appears most likely northwest IL
across southern IA. The airmass in all of these areas will likely
feature ample low-level moisture (i.e. dewpoints in the low to mid
70s), warm surface temperatures (highs in the low 90s), and at least
modestly steep mid-level lapse rates. This will result in strong to
extreme buoyancy, with MLCAPE values exceeding 3000 J/kg from
northeast KS into southern IA, northern MO, and west-central IL.

Complex surface pattern will likely yield limited predictability for
the primary severe hazard this evening. Given the extreme buoyancy
and moderate mid-level flow, any more cellular development that is
able to mature should become supercellular, with all severe hazards
possible, including very large hail and tornadoes. Storm interaction
and strong downdrafts will likely make maintaining a discrete mode
difficult, but low-level hodographs support the potential for a
strong tornado, particularly from 00 to 03Z amid a strengthening
low-level jet.

Lastly, early morning strong to severe thunderstorms are possible
across central/eastern NE as a secondary branch of the low-level jet
develops in response to another shortwave trough moving into the
central High Plains.

...Ohio Valley/Central Appalachians/Mid-Atlantic States...
A moist and unstable airmass will be in place today across much of
the region, with surface dewpoints generally in the lower 70s F.
While some thunderstorms are ongoing early today, additional and
more potent thunderstorm development is expected into the afternoon
as the boundary layer destabilizes. These storms will be further
influenced by a pair of weak eastward-moving MCVs, one over the
upper Ohio River Valley and the other over the central Appalachians.
Damaging winds, associated with water-loaded downbursts, will be the
primary hazard regionally.

..Mosier/Flournoy.. 06/10/2026

$$

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ACUS01 KWNS 230858
SWODY1
SPC AC 230856

Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0356 AM CDT Tue Jun 23 2026

Valid 231200Z - 241200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE CENTRAL HIGH PLAINS...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE MID ATLANTIC...

CORRECTED FOR TEXT

...SUMMARY...
Severe storms capable of 2+ inch diameter hail, 75+ mph gusts, and
isolated tornadoes are expected from the central High Plains into
parts of the central and southern Plains today into tonight.
Damaging gusts and perhaps a brief tornado may occur with storms
along the Mid-Atlantic. Scattered storms capable of isolated severe
wind/hail are possible across the northern Plains into the upper
Mississippi Valley.

...Synopsis...
A mid-level trough will impinge on the Eastern Seaboard while upper
ridging builds over the western into central CONUS today. Multiple
mid-level impulses are poised to traverse the upper ridge,
supporting at least scattered thunderstorm development in multiple
rounds across the Plains. These rounds of storms will encompass the
entire period (12Z Tuesday morning through 12Z Wednesday morning),
resulting in a complex forecast. Nonetheless, stronger flow aloft
associated with the ridge will advect an EML atop seasonal low-level
moisture, resulting in enough buoyancy and vertical wind shear to
support an appreciable severe threat, especially over the central
High Plains. Otherwise, a cold front approaching the East Coast will
support a line of severe thunderstorms over the Mid-Atlantic.

...Portions of the central High Plains...
By afternoon peak heating, upslope flow beneath a glancing mid-level
impulse will support the initiation of at least isolated storms.
These storms will develop atop a relatively mixed boundary layer and
surface dewpoints approaching 60 F, overspread by 9 C/km mid-level
lapse rates, resulting in moderate to locally strong buoyancy (i.e.
3000+ J/kg MLCAPE). Strong vertical wind shear will also be in
place, with 50 kts of effective bulk shear driven by elongated
hodographs with modest low-level curvature. Supercells will be the
primary storm mode, accompanied by a threat for all hazards. Given
the potential for a mixed boundary layer, intense gusts well
exceeding 75 mph will be possible, in addition to hailstones
potentially reaching the 2-3.5 inch range. Any supercells that can
ingest terrain-induced low-level vertical vorticity may be
accompanied by a landspout/hybrid tornado threat.

...Portions of the central and southern Plains...
A surface boundary currently resides along the Red River, with
thunderstorms developing all along this boundary from the TX
Panhandle to central MS. At the start of the forecast period (12Z
Tuesday), an established low-level jet will be in the process of
transporting a moist low-level airmass northward, perhaps
encouraging northward movement of the surface boundary as well.
However, an MCS may develop somewhere along the KS/OK border at the
start of the period along an elevated boundary, which will drift
southeastward through the late morning/early afternoon hours. The
evolution of this MCS and interacting convection with the
aforementioned surface boundary introduces considerable uncertainty
to the forecast, especially for late afternoon/early evening storms.

If the MCS and merging surface boundary convection linger over the
southern Plains through the day, later severe potential may be
reduced. However, if convection can exit the Plains or somehow
dissipate by late morning/early afternoon, enough destabilization
may take place for an evening severe threat. Should the later
scenario unfold, convective initiation over the southern High Plains
may result in severe hail/wind producing supercells merging into a
cold-pool driven MCS, which in turn may produce a severe wind swath
with 75+ mph gusts. Given so much uncertainty with the details of
this forecast, a broad area of 15 percent/CIG1 probabilities were
introduced for portions of the central and southern Plains.
Considerable adjustments to this forecast (upgrades or probabilities
removal) may be needed depending on convective and subsequent
modified environmental evolution through the first half of the
period.

...Parts of the Northern Plains...
Cold temperatures aloft and 8+ C/km mid-level lapse rates will
accompany the passage of an upper low over parts of the northern
Plains into the Upper MS Valley. By afternoon peak heating,
thunderstorms initiating along the periphery of the upper low, amid
a belt of stronger flow aloft (driving elongated hodographs) will
support multicells and perhaps transient supercells capable of
isolated severe wind and hail.

...Mid-Atlantic...
By late morning into early afternoon, surface temperatures warming
into the 80s F amid 70+ F dewpoints will yield over 2000 J/kg
MLCAPE, but distributed through tall/thin profiles given poor (5-6
C/km) mid-level lapse rates. Nearly unidirectional tropospheric wind
profiles will yield nearly 40 kts of effective (speed) shear, which
will favor multicellular development and ultimately a squall line
along/ahead of the cold front. Damaging gusts are expected to be the
main threat, though a brief tornado may also occur wherever locally
backed near-surface winds may be realized.

..Squitieri/Halbert.. 06/23/2026

$$

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