No watches are valid as of Wed Apr 22 17:25:01 UTC 2026.MD 0496 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR SOUTHERN LOWER MI...NORTHERN IN...AND NORTHWEST OH
Mesoscale Discussion 0496
NWS Storm Prediction Center Norman OK
1137 AM CDT Wed Apr 22 2026
Areas affected...far southern Lower MI...northern IN...and northwest
OH
Concerning...Severe potential...Watch unlikely
Valid 221637Z - 221900Z
Probability of Watch Issuance...20 percent
SUMMARY...Thunderstorm coverage will increase over the next couple
of hours, and storms will persist into early evening. The strongest
storms may produce marginally severe hail near 1 inch diameter and
locally strong gusts. A watch is not currently expected.
DISCUSSION...An isolated thunderstorm over southeast Lake Michigan
has persisted over the past hour as it slowly approaches the MI/IN
coast. During this time, MRMS MESH has estimated hail to near 1
inch. Most recently, 5 and 7 km CAPPI has decreased and echo tops
have lowered. It is unclear if this storm will continue inland. If
so, it could become reinvigorated as it moves into modestly better
low-level moisture near a surface boundary extending west to east
across far southern Lower MI/northern IN and northwest OH.
Additional storm development is expected near/south of this surface
boundary over the next couple of hours as strong heating continues.
Steepened low-level lapse rates may support locally strong gusts
with this activity. Additionally, cool temperature aloft are
supporting modest midlevel lapse rates, fostering MUCAPE around 1000
J/kg. Strengthening northwesterly flow aloft may aid in a few better
organized cells capable of producing marginally severe hail through
early evening. Given the overall modest environment, a severe
thunderstorm watch is not currently expected.
..Leitman/Mosier.. 04/22/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CLE...ILN...DTX...IWX...GRR...IND...LOT...
LAT...LON 41868712 42048692 42258625 42318524 42308506 42238434
41998372 41738331 41508318 40638316 40268362 40158458
40348532 40858626 41368683 41758706 41868712
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0737 AM CDT Wed Apr 22 2026
Valid 221300Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING FOR PARTS OF THE HIGH PLAINS/NORTHERN PLAINS...AND
FROM NORTHEAST INDIANA INTO NORTHERN OHIO...
...SUMMARY...
Isolated strong-severe thunderstorms with strong gusts and hail will
be possible across parts of the High Plains this afternoon and
evening, as well as from northeast Indiana into northern Ohio.
...High Plains this afternoon/evening...
In response to a shortwave trough digging south-southeastward over
BC/AB, a closed low over the Great Basin will evolve into a more
open wave and eject northeastward to the northern High Plains by
early Thursday. An associated, deep lee cyclone will develop
eastward from MT to near the ND/SK border, with a lee trough
extending southward into the central/southern High Plains. East of
the lee trough, low-level moisture (boundary-layer dewpoints in the
55-60 F range) will spread northward today from TX/OK to KS/NE.
Diurnal mixing will likely limit the quality of the moisture farther
north into the Dakotas. Thus, a few high-based thunderstorms will
be possible this afternoon/evening from NE into SD along the lee
trough with deep mixing, where inverted-v profiles will favor strong
outflow gusts.
A narrow zone of moderate buoyancy is expected along the dryline
from southwest NE and western KS into west TX, where deep-layer
vertical shear will be sufficient for supercells. Only limited
height falls and a warm elevated mixed layer, in combination with
somewhat limited parcel residence times in the dryline circulation,
suggest that storm coverage will be isolated at best. There will be
a conditional threat for isolated large hail with any sustained
storms.
...Dakotas tonight...
The threat for thunderstorms may increase tonight as a result of
ascent preceding the midlevel trough, and a modest increase in
low-level moisture with a strengthening low-level jet. Much of the
convection will likely be rooted above the surface, but could still
produce strong outflow gusts and marginally severe hail.
...IN/OH this afternoon/evening...
Residual low-level moisture and surface heating along a diffuse
baroclinic zone will support thunderstorm development this afternoon
from northeast IN into northern OH. Though deep-layer wind profiles
will not be particularly strong, relatively cool midlevel
temperatures and weak-moderate buoyancy could support marginally
severe hail and gusty outflow winds with the strongest storms.
..Thompson/Bentley.. 04/22/2026
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1128 AM CDT Wed Apr 22 2026
Valid 221630Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING FOR PARTS OF THE HIGH PLAINS/NORTHERN PLAINS...AND
ACROSS FAR SOUTHERN LOWER MICHIGAN...NORTHEAST INDIANA INTO NORTHERN
OHIO...
...SUMMARY...
Isolated strong-severe thunderstorms with strong gusts and hail will
be possible across parts of the High Plains this afternoon and
evening, as well as from northeast Indiana into northern Ohio.
...Synopsis...
Recent surface analysis shows an airmass modifying under low-level
moisture advection across the southern and central Plains, with mid
50s dewpoints reaching through central KS and into eastern
NE/western IA. This moderate low-level moisture also extends
eastward from IA into northern IL and IN, just south of a stationary
boundary that demarcates a drier, more stable airmass across much of
the Great Lakes from the modifying airmass farther south/southwest.
This analysis also reveals a pair of surface lows, one over
north-central MT and the other over far northeast WY/far southeast
MT, linked by modest surface troughing. A wavy surface trough also
extends southward to another low over southeast CO. Thunderstorm
development is anticipated today/tonight near these lows and their
related surface boundaries. In particular, strong to isolated severe
thunderstorms appear possible near the northeast WY/far southeast MT
low as it moves eastward across SD, as well as in the vicinity of
the stationary boundary across northern IN and OH.
...IN/OH...
Weak surface low over southern Lower MI has already contributed to
thunderstorm development. The airmass downstream of this low, and
south of the stationary boundary that extends east-to-west near the
MI and IN/OH border vicinity, will likely destabilize throughout the
day amid continued low-level moisture advection and strong diurnal
heating. This destabilization coupled with low-level convergence
near the low and boundary will support increasing thunderstorm
coverage. Deep-layer wind profiles will be modest, but cool
mid-level temperatures and weak-moderate buoyancy could support
isolated severe hail and gusty outflow winds with the strongest
storms.
...High Plains...
Primary surface low over central MT is forecast to deepen today as a
closed upper low currently over the Great Basin ejects northeastward
while evolving towards a more open wave. At the same time, a
secondary surface low (currently over far northeast WY/far southeast
MT) is forecast to move eastward across SD, interacting with the
modifying airmass across the northern/central Plains. Expectation is
for this airmass to be deeply mixed, with perhaps some minimal
buoyancy atop the well-mixed boundary layer. Development of a few
high-based thunderstorms is possible this afternoon/evening from NE
into SD, as well as northeast MT, along the trough where deep mixing
and inverted-v profiles will favor strong outflow gusts.
Farther south, an even more conditional risk is anticipated along a
sharpening dryline from southwest NE and western KS into west TX.
Given the limited large-scale forcing and only weak low-level
convergence, warm mid-level temperatures and related capping
associated with a notable elevated mixed layer will likely suppress
thunderstorm development. Here, deep-layer vertical shear will be
sufficient for supercells, and a conditional risk for large hail and
strong gusts exists with any updrafts that are able to persist and
mature.
...Western/Central NE into the Dakotas...
Additional thunderstorms are possible tonight from western/central
NE into the Dakotas as an eastward-progressing cold front interacts
with low-level moisture continuing to advect northward across the
Plains and a strengthening low-level jet. These storms will likely
be elevated behind the front, with some isolated hail possible early
in the convective cycle. Additionally, mid-level dry air will likely
remain across the region, supporting the potential for strong
outflow gusts despite the storms elevated character.
..Mosier/Lyons.. 04/22/2026
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1222 PM CDT Wed Apr 22 2026
Valid 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN
KANSAS INTO SOUTHERN MINNESOTA...
...SUMMARY...
Severe thunderstorms will be possible from southern Kansas into
southern Minnesota on Thursday. Large hail to very large hail,
damaging winds, and a few tornadoes are possible.
...Synopsis...
A short-wave trough initially over the northern High Plains Thursday
morning is forecast to shift east across the northern Plains into
the upper MS Valley in tandem with a belt of 50-60 kt
south-southwest winds in the mid levels. A secondary, lower-latitude
disturbance will advance into western KS and the OK/TX panhandles
late Thursday afternoon into evening, along with a more zonal
mid/upper-level jet streak. At the surface, the primary cyclone
attendant to the northern Plains system is expected to undergo
occlusion over southern into central Manitoba, while a trailing cold
front progresses east through the northern Plains into the upper MS
Valley. A pre-frontal trough or pseudo-dryline will precede the cold
front, extending from western MN through western IA and eastern NE
into central KS by early to mid afternoon. A secondary surface low
is forecast to deepen across portions of southwest KS or northwest
OK Thursday afternoon in response to the approach of the
lower-latitude disturbance mentioned above. A more classic dryline
will extend south from that low through western OK into western
north TX during the peak of the diurnal heating cycle.
...Upper MS Valley and upper Midwest through the mid/lower MO Valley
into central/eastern KS...
A broad, nocturnal, low-level wind maximum will develop across the
Great Plains tonight (Wed. night), enhancing the poleward flux of an
increasingly moist boundary layer beneath a residual EML plume
residing across the same region. The moisture increase beneath a
capping inversion at the base of the EML may result in considerable
cloud cover Thursday afternoon across portions of the warm sector
air mass. Where cloud breaks occur, model soundings indicate the
potential for MLCAPE to approach 1000-1500 J/kg across portions of
southern MN to as high as 2000-3000+ J/kg in central and eastern KS.
By early to mid afternoon, convergence along the pre-frontal
trough/dryline coupled with increasing height falls/forcing for
ascent are expected to support widely scattered thunderstorms from
portions of central and southern MN through eastern NE and western
IA, into at least northeast KS. While the strongest mid/upper-level
wind fields are expected to remain to the immediate west of the
initiating boundary, a corridor of 40-45 kt effective bulk shear
will overlie the western fringe of the warm sector, supporting
organized multicells and supercells as the initial storm mode with
an attendant threat for large to very large hail and a few
tornadoes. Subsequent upscale growth into a broken band of storms is
expected Thursday evening into Thursday night across portions of
eastern MN into western WI, western and central IA, southeast NE,
northeast KS, and northwest MO. Damaging wind potential will
increase with that mode change, with a continued risk for a few
tornadoes.
The most favorable overlap of moderate to strong instability and
vertical wind shear is expected to develop across central into
eastern KS Thursday afternoon into evening. Here, a few intense
supercells capable of all severe-weather hazards appear possible,
and a categorical upgrade to a level 3/Enhanced Risk may be required
in subsequent Day 1 outlooks.
...OK into north TX...
Moderate to strong instability (MLCAPE of 2500-3500 J/kg) is
expected to develop east of the dryline by late afternoon into early
evening on Thursday. However, strong capping at the base of the EML
casts considerable uncertainty on whether storms can develop. While
the strongest forcing for ascent associated with the secondary
short-wave trough is expected to remain across KS, subtle mid-level
height falls are forecast across northern OK. Otherwise, strong
heating to the west of the dryline and resultant deepening
circulations along it will be the primary mechanism responsible for
any storm development.
On the condition that isolated storms develop and become sustained,
the kinematic environment will support supercells capable of very
large hail and tornadoes. This is especially the case during the
evening hours as low-level shear strengthens in response to the
amplification of the low-level jet.
..Mead.. 04/22/2026
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