RSS Mesoscale Discussions from Storm Prediction Center
Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0752 AM CDT MON APR 27 2026
...Severe thunderstorms expected over parts of the mid Mississippi
Valley and Mid-South today and tonight...
* LOCATIONS...
Southern and Central Illinois
Central and Eastern Missouri
Western Kentucky
Western Indiana
Northern and Central Arkansas
Western Tennessee
* HAZARDS...
Several tornadoes, a couple intense
Widespread damaging winds
Scattered large hail, some baseball size
* 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.
Preparedness actions...
Review your severe weather safety procedures for the possibility
of dangerous weather today. Stay tuned to NOAA Weather Radio,
weather.gov, or other media for watches and warnings. A tornado
watch means that conditions are favorable for tornadoes to form
during the next several hours. If a tornado warning is issued for
your area, move to a place of safety, ideally in a basement or
interior room on the lowest floor of a sturdy building.
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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0249 PM CDT Mon Apr 27 2026
Valid 272000Z - 281200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS
EAST/SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...WESTERN KENTUCKY...AND
NORTHWEST TENNESSEE...
...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
(EF3+), widespread severe/damaging wind gusts, and scattered large
to very large hail.
...20z Update...
Only minor adjustments were made to extend the Marginal Risk back
into southeastern Kansas/northeastern Oklahoma to account for storms
initiating over the last hour.
The Moderate Risk remains unchanged with this update. The morning
MCS is now moving through eastern Illinois/southern Indiana. Further
west in Missouri and western Illinois, modifying remnant outflow
remains near the St. Louis Metro. Cumulus south of this boundary
across southeastern Missouri into southern Illinois, cumulus within
the warm sector is deepening. Increasing MLCAPE/steepening lapse
rates are nosing northward in southern central Missouri and
south-central Illinois.
Just to the west of the Mississippi River, radar shows occasional
attempts at initiation within the open warm sector. While the
details continue to evolve, it likely that a corridor of conditional
threat for strong-intense tornadoes will develop from the Missouri
Bootheel into southern Illinois/western Kentucky. Within this region
strong daytime heating has led to a volatile air mass, with moderate
to strong MLCAPE 2000-3000 J/kg and strong deep layer shear. VAD
profiles frm PAH (Paducah, KY) and LSX (St. Louis, MO) indicate a
rich SRH environment of around 200-300 m2/s2 in the 0-1 km layer. It
is likely that supercells capable of all hazards, including
strong-intense tornadoes, large to very large hail, and damaging
winds. Will develop across this region soon. See MCD571 for
additional information.
The conditional threat for strong tornadoes will extend as far south
as the Arklatex into portions of western Tennessee. Through time,
storm mode will shift to become linear with the southward moving
front, which will bring an increase into the evening of damaging
wind threat. Line embedded tornadoes, some of which may be strong,
will continue to be a threat into the evening.
..Thornton.. 04/27/2026
.PREV DISCUSSION... /ISSUED 1150 AM CDT Mon Apr 27 2026/
...Mid Mississippi Valley/Midwest into the Mid-South/Lower
Mississippi Valley...
Forecast scenario largely unchanged in that a very active
severe-weather/tornado day is expected regionally, especially into
late afternoon and this evening. Initially, a relatively long-lived
linear cluster of convection persists at late morning across
east-central/south-central Illinois, with additional initially
elevated storms on its eastern/southern periphery, moving from
eastern Illinois into Indiana, with severe hail and damaging winds
persisting as early day hazards.
Over time, air mass will continue to moisten and rapidly destabilize
along/south of the MCS-associated outflow from central Missouri into
south-central Illinois. A mid/upper-level trough will eject
northeastward from the northern/central Plains into the Midwest and
middle Mississippi Valley through the period. Low-level mass
response will encourage the primary surface low to consolidate
across Minnesota/Wisconsin by this evening, with a warm front
effectively delineated by the morning convection.
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
into mid-afternoon across the mid Mississippi Valley/Mid-South ahead
of the surface cold front, and perhaps along weak low-level
confluence zones in the open warm sector including generally near
the confluence of the Mississippi/Ohio Rivers southward into the
Mid-South.
These supercells will exist in a very favorable environment for
tornadoes through the afternoon and evening, and multiple strong to
intense tornadoes (EF2/3+) appear likely, especially from parts of
Missouri into Illinois along/near the effective front. This strong
tornado potential will also likely extend farther south within the
warm sector into the Mid-South.
By early evening, convection will probably tend to consolidate into
clusters of supercells and then more linear segments with some
increase in damaging wind potential aside from large hail and a
continued multi-mode tornado risk tonight.
...ArkLaTex into Texas...
While storm coverage may trend lesser with southwest extent, the
potential for at least isolated intense storms will exist across the
region. Supercells capable of producing large to very large hail and
occasional damaging winds are expected. Increasing low-level
warm/moist advection tonight could foster additional robust
thunderstorms along the retreating dryline and eventually the
southward-moving cold front.
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 PM CDT Mon Apr 27 2026
Valid 291200Z - 301200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
ALLEGHENY PLATEAU TO THE MID ATLANTIC...AND ALSO FROM PARTS OF TEXAS
TO THE CENTRAL GULF COAST REGION...
...SUMMARY...
Strong to locally severe storms are possible across parts of the
Allegheny Plateau into Mid Atlantic, as well as from west-central
Texas to the central Gulf Coast, mainly Wednesday afternoon and
evening.
...West-central TX into the Southeast/Central Gulf Coast...
A substantial buoyancy reservoir is expected to persist from parts
of central/south TX toward the lower MS Valley on Wednesday. Due to
substantial early-week convection, considerable uncertainty remains
regarding the potential for an ongoing isolated severe threat in the
morning, and the location of the composite front/outflow and
potential redevelopment during the afternoon and evening.
With favorable instability and deep-layer shear, the environment
will be conditionally favorable for organized convection, including
potential for large hail and locally damaging wind. Large-scale
ascent is likely to be displaced north of the primary surface
boundary and strongest instability, so storm coverage remains
uncertain, but isolated supercells and/or small clusters will be
possible along/south of the front. An increase in severe
probabilities may eventually be needed across parts of this region,
depending on observational and guidance trends regarding boundary
placement and anticipated storm coverage.
...Allegheny Plateau to the Mid Atlantic...
A vigorous mid/upper-level shortwave trough is forecast to move from
the Midwest toward the Mid Atlantic on Wednesday. An attendant
surface low will move from the upper OH Valley toward the Delmarva
region, with trailing front extending southwestward into parts of
the Southeast, Carolinas, and Virginia by afternoon. The expectation
for substantial early-day cloudiness and precipitation continues to
result in uncertainty regarding potential for appreciable
destabilization during the afternoon. If sufficient destabilization
can occur, then favorable large-scale ascent and deep-layer shear
related to the approaching shortwave trough could support organized
storms, with a threat of damaging wind and possibly some hail.
Due to the lingering uncertainties regarding destabilization, a
broad Level 1/Marginal Risk is maintained with this outlook. An
eventual increase in severe probabilities will be possible for parts
of the region, depending on how the uncertainties are resolved.
..Dean.. 04/27/2026
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