ACUS01 KWNS 161247
SWODY1
SPC AC 161246

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0746 AM CDT Fri May 16 2025

Valid 161300Z - 171200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF EAST-CENTRAL AND SOUTHEAST MISSOURI...WESTERN AND CENTRAL
KENTUCKY...SOUTHERN ILLINOIS AND INDIANA...SOUTHWEST
OHIO...NORTHWEST TENNESSEE...AND NORTHEAST ARKANSAS...

...SUMMARY...
A regional outbreak of severe thunderstorms is likely this afternoon
into tonight across parts of the mid Mississippi, Ohio and Tennessee
Valleys. This will include intense supercells associated with
tornadoes, large hail and wind damage. Several strong tornadoes are
expected, and a long-track high-end tornado will be possible. From
the evening into the overnight, a bowing line segment is expected to
form with potential for tornadoes and damaging winds, some possibly
greater than 75 mph.

...Mid Mississippi and Ohio Valley/Tennessee Valley Region...
As an upper-level low near the MN/ND border shifts east today, a
mid-level jet streak will move from the Plains into the
mid-Mississippi Valley. A surface cold front will move east across
the Great Lakes, Midwest and OH/TN Valley region this afternoon and
tonight. An expansive warm/moist sector will destabilize during the
day, setting the stage for a regional severe weather outbreak this
afternoon and tonight.

Scattered severe thunderstorms, with a history of large hail, were
ongoing at 13z from northeast AR into eastern KY. Clusters of severe
storms, including supercells, will continue moving northeast within
this corridor through at least early afternoon. The eventual
longevity of these storms remains uncertain, however downstream
diurnal destabilization could allow storms with a severe hail/wind
threat to move into WV/western VA this afternoon.

In the wake of these morning storms, destabilization will occur as a
warm front lifts north, with strong instability (MLCAPE in excess of
2500 J/kg) developing from portions of eastern MO east into the
OH/TN Valley region, and south in advance of the front into eastern
TX. The presence of strong mid-level flow will contribute to
deep-layer shear averaging 50 kts or higher across a large area.

Vigorous redevelopment of severe storms is expected by early
afternoon across southern/eastern MO as height falls overspread the
area. More isolated development is expected southward along the cold
front towards 00Z. Initial storm development will strongly favor
supercell storm mode with all severe hazards possible, including the
potential for strong tornadoes across the Moderate/Enhanced Risk
areas where low-level shear will be strongest. Large to very large
hail will also be possible with mature supercells this afternoon
through early evening. As storms continue moving east across the
OH/TN Valley region, eventual upscale growth into multiple bowing
segments is expected. The tornado threat will continue, especially
with QLCS circulations, and significant severe gusts will also be possible.

...Ark-La-Tex/Lower Mississippi Valley...
Warm mid-level temperatures will tend to delay thunderstorm
initiation along the southward-trailing cold front into northeast TX
until later in the day, however at least isolated development is
expected towards 22z-00z. MLCAPE in excess of 3000 J/kg and 45-55
kts of deep-layer shear oriented favorably relative to the front
suggests a supercell mode with large to very large hail, along with
damaging gusts. Although weaker low-level shear will be present in
this area, some potential for a tornado will exist with any mature
supercell. With time, storms may increase in coverage and begin to
cluster in an environment favorable for a continued severe wind/hail threat.

...Portions of the Mid-Atlantic/northern DelMarVa Peninsula...
As the southern portion of the long-lived MCS over PA/NY continues
moving east/southeast today, the potential will exist for
re-development of organized storms, including supercells, over
portions of southeast PA/southern NJ and the northern DelMarVa
peninsula. With moderate west/northwest flow in place to the east of
the upper level ridge, RAP/HRRR forecast soundings depict sufficient
deep shear and moderate instability for a severe hail and wind risk.
Some consideration was given for higher severe probabilities in this
area, however uncertainty remains on the location of a corridor of
greater risk.

..Bunting/Marsh.. 05/16/2025

$$
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ACUS01 KWNS 191253
SWODY1
SPC AC 191251

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0751 AM CDT Mon May 19 2025

Valid 191300Z - 201200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FAR NORTH
TEXAS...MUCH OF CENTRAL AND EASTERN OKLAHOMA...SOUTHEAST
KANSAS...AND THE OZARKS...

...SUMMARY...
Significant severe weather is likely from the central/southern
Plains into the the Ozarks today into tonight. All severe weather
hazards are expected, to include tornadoes (some potentially strong
to intense), very large hail, and severe winds.

... Synopsis ...

A large, amplified trough over the Rockies will shift slowly
eastward into the Plains today. Embedded within this longwave
trough, a complex evolution is expected. Downstream of the trough, a
negatively tilted shortwave trough will deepen and close off across
the northern Plains. Meanwhile, upstream, a closed low currently
over Idaho will dig southeastward, open up, and eject into the
central Plains.

As this evolution occurs, strong midlevel flow (in excess of 50
knots) will remain across much of the central and southern Plains
through the forecast period. By late in the afternoon, midlevel flow
will strengthen to perhaps 70 knots in response to the ejecting low
into the central Plains.

At the surface, the main synoptic low will be somewhat
diffuse/elongated over northwest Kansas into southwest Nebraska this
morning. Extending southward from this low, a dryline will stretch
through western Kansas into the Oklahoma and Texas Panhandles,
continuing into west Texas. A warm front will extend eastward near
the Kansas-Nebraska border before curving southeastward into
Missouri into the southern Appalachians.

The surface low is expected to gradually fill today as it slowly
moves east/northeast into south-central Nebraska, Despite this, rich
Gulf moisture will be maintained across the central and southern
Plains. Dewpoint temperatures at or above 70F will advect northward
from Texas through Oklahoma perhaps to as far north as northeast Kansas.

During the afternoon, strong diurnal heating along the dryline may
result in a sub-synoptic low developing across northwest Oklahoma.
This low will slowly progress east along the Oklahoma-Kansas border
during the afternoon, weakening with time.

... Southern and Central Plains into the Ozarks ...

A strongly sheared atmosphere will already be in place at the start
of the forecast period. As diurnal heating commences and 70F
dewpoints advect northward, the atmosphere across much of the
central and southern Plains will become strongly to extremely
unstable as well, with surface-based CAPE values between 3000-5000
J/kg across the region.

Multiple rounds of storms are expected across the region today. One
such initiating mechanism looks to be a subtle shortwave trough
embedded in the larger scale flow currently across eastern New
Mexico. This wave should initiate thunderstorms across eastern
Oklahoma northward into eastern Kansas by midday. It is unclear if
these storms will initially be elevated, but as they move east and
the atmosphere destabilizes further ahead of the line, a transition
to more surface-based convection should occur. At the same time, the
low-level jet is forecast to strengthen/reorganize across eastern Oklahoma/western Arkansas into western Missouri. This will yield
ample low-level curvature to the hodograph. Thus, given the strongly
sheared environment in place, supercells capable of producing all
severe hazards, including strong tornadoes, will be possible with
this first round of storms.

By mid-to-late afternoon, 30-60 meter mid-level height falls should
overspread the dryline as it mixes east into central Kansas
southward into western north Texas. Rapid thunderstorm development
is expected along the dryline given the forecast extreme
instability. These thunderstorms should develop west of the better
low-level jet/flow, where the low-level flow is expected to be a
little more veered than across eastern Kansas/Oklahoma. This veered
low-level flow still will result in a strongly sheered environment,
but with more straight hodographs and less low-level curvature. The
result should be another round of supercells, albeit with a tendency
to split. These supercells will be capable of producing very large
hail and tornadoes. The number of supercells across the dryline
combined with a propensity to split, may result in destructive
interference and result in a more episodic hail and tornado threat.

In addition to the hail and tornado threat, the number of expected thunderstorms in the presence of a very moist and unstable
atmosphere with steep lapse rates may result in strong downdraft
winds. The most likely region for this will be across portions of
northeast Oklahoma, northwest Arkansas, southeast Kansas, and
southwest Missouri. A 45% wind area was included in this outlook.

... Southern Illinois into Southern Appalachians ...

Along the northern periphery of shortwave ridging over the
Southeast, a midlevel jet streak will cross the southern
Appalachians during the afternoon. Here, an influx of steep midlevel
lapse rates atop rich boundary-layer moisture will yield strong
surface-based instability along/south of a warm front draped across
the region. Scattered thunderstorms will spread east-southeastward
along/south of the front from TN into the southern Appalachians,
where the favorable buoyancy and around 40-50 kt of effective shear
will promote organization into clusters and a couple splitting
supercell structures. Damaging winds and large hail will be possible
with the strongest storms.

Overnight, additional thunderstorms may develop across southern
Illinois and western Kentucky in association with warm-air advection
ahead of the main area of thunderstorms to the west. These
thunderstorms will also pose the potential for small hail and
isolated wind damage.

..Marsh/Smith.. 05/19/2025

$$
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ACUS01 KWNS 081208
SWODY1
SPC AC 081207

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0707 AM CDT Sun Jun 08 2025

Valid 081300Z - 091200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING FROM THE EASTERN TEXAS PANHANDLE INTO SOUTHERN OKLAHOMA
AND NORTHWEST/NORTH-CENTRAL TEXAS...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
FROM THE MID-ATLANTIC REGION INTO GEORGIA....

...SUMMARY...
A severe weather outbreak is possible across the southern Plains
today. A few tornadoes, destructive wind gusts of 80-100 mph, and
giant hail up to 5 inches in diameter are likely. Strong gusts, and
perhaps a couple of tornadoes, are also possible along portions of
the East Coast.

...OK/TX...
Broad west-northwesterly flow is present today across the
central/southern Plains states, with a surface cold front sagging
southward across KS. Ahead of the front, a very moist
boundary-layer air mass is in place across much of OK and TX, with
dewpoints in the upper 60s and lower 70s. Strong daytime heating
and near dry-adiabatic low/mid-level lapse rates will yield a large
reservoir of extremely high CAPE values across western OK and
northwest TX.

Rapid development of intense thunderstorms will ensue by mid/late
afternoon along the cold front over northwest OK and along a complex
dryline structure over the eastern TX Panhandle. Strong deep layer
shear will favor supercells, despite rather weak low-level winds.
Very large hail, damaging winds, and a few tornadoes will be
possible as these storms track southeastward across western/central
OK and congeal into one or more bowing segments. Recent CAM
solutions suggest pockets of deep boundary-layer mixing, with some
areas heating into the mid 90s while dewpoints drop into the 50s.
If this scenario develops, significant wind and hail would remain a
concern, but the overall risk of tornadoes would be reduced.

The risk of widespread destructive winds will increase through the
evening as the convective complex tracks into northwest and
north-central TX. The activity make remain intense as far east as northern/central LA tonight.

...Central/North TX early afternoon...
A cluster of strong thunderstorms is ongoing this morning between
ABI and LBB. Other isolated cells are forming in eastern NM north
of TCC. Given the very unstable environment, any one of these
clusters of storms could potentially persist through the day and
track southeastward into parts of central TX. Large hail and
damaging winds would be the main concerns.

...Mid Atlantic Region...
A shortwave trough currently over OH will track eastward today, with large-scale ascent overspreading the Mid-Atlantic states by
afternoon. A moist surface air mass is present across much of
VA/MD/NC and vicinity with dewpoints in the upper 60s. Persistent
clouds and weak mid-level lapse rates will limit destabilization.
However, it appears likely that storms will develop off the Blue
Ridge by mid afternoon and spread eastward toward the coast.
Forecast soundings show sufficient low and deep layer shear for
supercell structures capable of damaging wind gusts and perhaps a
few tornadoes.

...GA/SC...
A large MCS has persisted overnight across parts of AL/GA, with a
few strong storms along its leading edge. Given a few hours of
daytime heating, these storms may pose a risk of damaging wind gusts
as they spread eastward toward the coast.

..Hart/Bentley.. 06/08/2025

$$
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ACUS01 KWNS 171259
SWODY1
SPC AC 171258

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0758 AM CDT Tue Jun 17 2025

Valid 171300Z - 181200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
KANSAS AND NORTHERN OKLAHOMA...

...SUMMARY...
Severe thunderstorms producing numerous to widespread damaging
winds, scattered large hail (isolated 2+ inches), and a few
tornadoes are expected today across parts of the central/southern
Plains and lower/mid Missouri Valley. The greatest threat for
destructive gusts up to 70-100 mph is forecast across portions of
Kansas and northern Oklahoma.

...Central/Southern Plains into the Lower/Mid Missouri Valley...
A small but intense bow echo that moved south-southeastward across
parts of KS overnight should continue to weaken this morning across
northeast OK. But in the short term, an isolated threat for severe
winds may continue until the cluster fully dissipates. Across
eastern CO, occasional severe hail may occur with marginal
supercells for another hour or two before additional weakening
occurs. The net effect of this overnight/early morning convection on
the severe potential across the southern/central Plains remains
uncertain. But, a trailing outflow boundary from the decaying MCS
now in northeast OK may prove instrumental in focusing significant
severe potential this afternoon/evening.

A subtle mid-level shortwave trough over the eastern Great Basin and
central Rockies will continue to move eastward over the adjacent central/southern High Plains by this evening. At the surface,
further deepening of a low over southeast CO is anticipated through
the day, with this low forecast to develop into the TX Panhandle by
early evening. A lee trough/dryline will extend southward from this
low, while a convectively reinforced boundary should extend
somewhere along/near the KS/OK border by mid to late afternoon, and
potentially northeastward into eastern KS as well. The airmass
across east-central CO into western KS was generally not
convectively overturned yesterday into early this morning, with the
12Z sounding from DDC still showing around 2800 J/kg of MUCAPE available.

Convective development and evolution remain uncertain later today.
Still, it appears likely that initially high-based thunderstorms
will develop over the higher terrain of central CO this afternoon,
and then spread east-southeastward over the adjacent High Plains
through the evening. Much of eastern CO and vicinity will be in a
post-frontal regime. But steep mid-level lapse rates and sufficient
low-level moisture should support the development of moderate
instability. Strong deep-layer shear should foster supercells
initially, with associated threat for mainly large to isolated very
large hail. Some upscale growth may eventually occur with this
activity as it spreads into western KS this evening, along with an
increased threat for severe/damaging winds.

Farther east into central/eastern KS and MO, severe potential
remains highly uncertain, with a myriad of possible solutions
offered by various high-resolution guidance. In general, current
expectations are for an increasing threat for numerous to
potentially widespread severe/damaging winds across parts of KS into
northern OK, with one or more intense clusters potentially
developing in tandem with a strengthening low-level jet this evening
across the southern/central Plains. Significant severe gusts of 75+
mph remain possible, along with a few tornadoes with any sustained
supercells along/near the boundary this evening as low-level shear
strengthens. Overall, severe probabilities have been expanded
southward some across the OK/TX Panhandles and northern/central OK,
in an attempt to account for where the outflow boundary/front may be
present this afternoon/evening. Additional adjustments to risk areas
are likely with later outlook updates pending additional
observational and model data.

...Mid-Atlantic into the Tennessee Valley/Southeast...
Diurnal heating of a seasonally moist low-level airmass will occur
today across the central Appalachians/southern Mid-Atlantic within a
modestly sheared environment. Thunderstorms are expected to develop
over higher terrain by early afternoon, and subsequently spread
eastward through the evening. Some of this activity may form into
loosely organized clusters. Occasional strong/damaging winds should
be the main severe threat with this activity, particularly across
parts of VA/MD where stronger instability is forecast.

Farther south into the TN Valley/Southeast, a weak mid/upper-level
trough with multiple embedded perturbations should advance slowly
eastward through the day. Similar to yesterday, daytime heating of a
moist airmass should foster moderate to locally strong instability
this afternoon. Around 25-30 kt of mid-level southwesterly flow and
similar values of deep-layer shear should support some loose
convective organization with multiple thunderstorm clusters that can
develop. Have expanded the Marginal Risk for isolated damaging winds southwestward to account for this potential.

..Gleason/Kerr.. 06/17/2025

$$
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ACUS01 KWNS 172001
SWODY1
SPC AC 172000

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Tue Jun 17 2025

Valid 172000Z - 181200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF NORTHERN OKLAHOMA AND SOUTHERN KANSAS...

...SUMMARY...
Severe thunderstorms producing numerous to widespread damaging
winds, scattered large hail (isolated 2+ inches), and a few
tornadoes are expected this afternoon and evening across parts of
the central/southern Plains. The greatest threat for destructive
gusts up to 70-100 mph is forecast across portions of southern
Kansas and northern Oklahoma.

...20z Update Southern Plains...
A convective reinforced outflow boundary across west-central KS
continues to slowly push southward across southwest portions of the
state to near the OK border. This boundary will likely serve as the
focus for robust convective development this afternoon and evening,
as indicated by elevated development farther east. To the north of
the primary surface heating, this initial activity may quickly grow
upscale into one or more clusters before spreading southeast and
becoming more surface-based with time. Large to very large hail,
damaging gusts and some tornado risk are likely with these storms.

Across northwest OK, and the northeastern TX Panhandle, additional,
more isolated storms are likely this afternoon along the southern
most modified outflow and pseudo-triple point area. Surface obs and
18z AMA/LMN RAOBs show substantial low-level shear, large buoyancy
and favorable deep-layer shear for supercells capable of very large
hail and a few tornadoes across northern OK and far southern KS.
Current expectations are still that initially cellular convection
will rapidly develop and pose a severe risk through the afternoon,
before growing upscale as it interacts with additional storms over
KS this evening. One or more organized bows/clusters, capable of
very strong damaging gusts, hail and a couple of tornadoes are
likely this evening. Will maintain the MDT risk with minimal
trimming on the northwest side near the advancing outflow.

...Southeast to the Mid Atlantic...
Several clusters of strong to occasional severe storms are ongoing
and expected to continue this afternoon/evening. Moderate buoyancy
within a very moist air mass could support occasional damaging gusts
from heavily water-loaded downdrafts. Some degree of organization
into loose clusters could continue, especially across AL where
storms have shown slightly stronger cold pools. However, the overall
potential for storm organization is low with vertical shear
remaining quite weak. The severe risk should begin to weaken through
the early evening. Some minor trimming was made to the severe
probabilities along the western edge of the MRGL.

...Rockies...
Scattered severe storms, including a few supercells, will continue
this afternoon. Confidence is highest in the severe threat remaining
near the I-25 corridor where more substantial heating has taken
place. Hail remains the primary risk, though a few damaging gusts
and a brief tornado remain possible.

..Lyons.. 06/17/2025

.PREV DISCUSSION... /ISSUED 1118 AM CDT Tue Jun 17 2025/

...KS/OK...
Overnight and morning thunderstorm activity has significantly
changed the overall forecast for severe storms across the central
Plains for today. A severe MCS overspread parts of southeast KS and
northeast OK a few hours ago, pushing an outflow boundary southward
into central OK. Strong heating is occurring to the north of this
boundary, where rapid destabilization is expected this afternoon
across northern OK/southern KS. A consensus of 12z model guidance
shows this to be the corridor of rapid and intense thunderstorm
development. Forecast soundings show substantial low-level shear,
steep lapse rates, and sufficient winds aloft for supercells capable
of very large hail and a few tornadoes. Relatively warm
temperatures in the 850-700mb layer are a negative factor for a
greater tornado concern. Through the evening, congealing outflows
will likely result in a larger MCS posing a risk of widespread
damaging wind gusts into northeast OK and perhaps parts of northwest AR/southwest MO.

...Eastern CO/Southeast WY...
Overnight storms also impacted the forecast for this region today.
Easterly low-level winds (enhanced by outflow) have transported
moisture westward into the foothills, where rapid thunderstorm
development is expected by early afternoon. Steep mid-level lapse
rates and seasonably cool mid-level temperatures, coupled with
sufficiently strong westerly flow aloft, will promote a risk of very
large hail in the strongest storms. A tornado or two is also
possible. It is unclear how far east this activity can make it into
the adjacent Plains, where persistent low-clouds and more stable
conditions will likely prevail. Refer to MCD #1330 for further
details.

$$
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ACUS01 KWNS 171955
SWODY1
SPC AC 171953

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0253 PM CDT Fri Apr 17 2026

Valid 172000Z - 181200Z

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

...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.

...20Z Update...
Severe probabilities have been adjusted to account for progression
of the cold front this afternoon. The remainder of the forecast is
unchanged. See MD 475 for short-term details of evolving tornado
risk along the Illinois/Wisconsin border.

..Wendt.. 04/17/2026

.PREV DISCUSSION... /ISSUED 1203 PM CDT Fri Apr 17 2026/

...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.

$$
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ACUS01 KWNS 271247
SWODY1
SPC AC 271245

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0745 AM CDT Mon Apr 27 2026

Valid 271300Z - 281200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
MISSOURI INTO ILLINOIS...

...SUMMARY...
Numerous severe thunderstorms are expected from the mid
Mississippi/lower Ohio Valleys into the Mid-South through this
evening, with a threat for multiple strong to intense tornadoes
(EF-3+), widespread severe/damaging wind gusts, and scattered large
to very large hail.

...Mid Mississippi Valley/Midwest into the Mid-South/Lower
Mississippi Valley...

An active severe weather day is forecast for much of the mid MS
Valley/lower OH Valleys into the Mid-South. Ongoing thunderstorms
this morning complicate the overall scenario to some extent, but a
very favorable corridor for intense supercells and strong tornadoes
is apparent this afternoon/evening across parts of MO into IL, where
a Moderate Risk (Level 4 of 5) has been introduced.

Elevated supercells with mainly a hail threat should persist for at
least a couple more hours this morning across the mid MS Valley as
strong low-level warm advection aids in continued influx of
sufficient MUCAPE amid strong deep-layer shear. Multiple
clusters/embedded supercells are also ongoing this morning across
western into northern MO. This activity should pose a greater threat
for scattered severe/damaging winds, along with some hail risk. The
tornado threat in the short term (this morning) remains unclear, but
it should eventually increase as the boundary-layer across central
MO continues to gradually destabilize/moisten. See Mesoscale
Discussion 565 for more details on the near-term severe risk with
these ongoing thunderstorms.

Current expectations are for the greatest severe risk to focus south
of these morning thunderstorms. A mid/upper-level trough will eject northeastward from the northern/central Plains into the Midwest and
mid MS Valley through the period. Low-level mass response will
encourage the primary surface low to consolidate across MN/WI by
this evening, with an effective warm front delineated by the morning convection. Aided by daytime heating and steep mid-level lapse
rates, a moderately to strongly unstable airmass is expected to be
in place by early to mid afternoon across much of central
MO/southern IL southward into the Mid-South and lower MS Valley.

Strengthening west-southwesterly flow aloft associated with a 50-70
kt mid-level jet will overspread much of the warm sector by peak
heating, and a 35-45 kt south-southwesterly low-level jet will both
provide ample low-level and deep-layer shear to support supercells.
Initially discrete surface-based development appears likely to occur
by 19-21Z across the mid MS Valley/Mid-South ahead of the surface
cold front, and perhaps along weak low-level confluence zones in the
open warm sector.

These supercells will exist in a very favorable environment for
tornadoes through the afternoon and evening, and multiple strong to
intense tornadoes (EF-2/3+) appear likely, especially from parts of
MO into IL along/near the effective front. This strong tornado
threat may also extend farther south into AR/TN, but confidence is
somewhat lower with southward extent due to weaker large-scale
forcing. Large to very large hail (2-3 inches in diameter) may also
occur with any sustained supercells.

By early evening, convection will probably tend to consolidate into
clusters capable of producing numerous to widespread damaging winds
from the mid MS Valley eastward into the lower OH Valley, before
eventually weakening tonight as instability gradually decreases. A
threat for QLCS and embedded supercell tornadoes will persist
through much of the evening and early overnight hours as well given
strong low-level shear forecast.

To the north of the ongoing morning convection across IA/northern
IL/WI, a lesser (but non-zero) severe risk is forecast. This region
will have less instability this afternoon, but strong shear. Have
maintained the Marginal/Slight Risks for the possibility of isolated
to locally scattered hail/damaging winds, and perhaps a couple of tornadoes.

...ArkLaTex into Texas...

Confidence in sustained convection occurring from the ArkLaTex
southward into TX is lower compared to locations farther north. But,
strong heating ahead of a surface dryline could support isolated to
scattered supercells capable of producing large to very large hail
and occasional damaging winds. Increasing low-level warm/moist
advection tonight could foster additional robust thunderstorms along
the retreating dryline and eventually the southward-moving cold
front. Severe probabilities have been expanded across these regions
to account for this potential.

..Gleason/Thornton.. 04/27/2026

$$
--- MultiMail/DOS
* Origin: Project Scorpio TEST (618:250/6)