RSS Mesoscale Discussions from Storm Prediction Center
WW 157 SEVERE TSTM IL MO 270905Z - 271500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 157
NWS Storm Prediction Center Norman OK
405 AM CDT Mon Apr 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
West-Central and Southwest Illinois
Eastern Missouri
* Effective this Monday morning from 405 AM until 1000 AM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
A tornado or two possible
SUMMARY...Elevated supercells will continue to pose a threat for
large hail this morning as they move from eastern Missouri into
parts of western Illinois. A thunderstorm cluster capable of
producing mainly severe/damaging winds will also spread into parts
of north-central/eastern Missouri later this morning. A tornado or
two will also be possible with this cluster.
The severe thunderstorm watch area is approximately along and 55
statute miles east and west of a line from 115 miles northwest of
Saint Louis MO to 40 miles east southeast of Poplar Bluff MO. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU7).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 156...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
26035.
...Gleason
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WW 156 SEVERE TSTM KS MO 270845Z - 271500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 156
NWS Storm Prediction Center Norman OK
345 AM CDT Mon Apr 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Eastern Kansas
Western and Central Missouri
* Effective this Monday morning from 345 AM until 1000 AM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
A tornado or two possible
SUMMARY...A cluster with embedded supercells will continue to move
quickly eastward this morning while posing a threat for scattered
damaging winds and large hail. A brief embedded tornado or two may
also occur.
The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 25 miles north of
Emporia KS to 60 miles east northeast of Knob Noster MO. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU6).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 154...WW 155...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
26040.
...Gleason
Read more
WW 0157 Status Updates
STATUS REPORT ON WW 157
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 ESE POF
TO 20 S FAM TO 5 SSW VIH.
..THOMPSON..04/27/26
ATTN...WFO...PAH...LSX...
STATUS REPORT FOR WS 157
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC003-013-047-055-059-061-065-069-077-081-083-087-119-127-133-
145-149-151-153-157-163-165-181-185-191-193-199-271340-
IL
. ILLINOIS COUNTIES INCLUDED ARE
ALEXANDER CALHOUN EDWARDS
FRANKLIN GALLATIN GREENE
HAMILTON HARDIN JACKSON
JEFFERSON JERSEY JOHNSON
MADISON MASSAC MONROE
PERRY PIKE POPE
PULASKI RANDOLPH ST. CLAIR
SALINE UNION WABASH
WAYNE WHITE WILLIAMSON
KYC007-035-039-075-083-105-139-145-157-271340-
KY
. KENTUCKY COUNTIES INCLUDED ARE
BALLARD CALLOWAY CARLISLE
FULTON GRAVES HICKMAN
LIVINGSTON MCCRACKEN MARSHALL
Read more
WW 0156 Status Updates
STATUS REPORT ON WW 156
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 NNE CNU
TO 15 S OJC TO 25 N SZL TO 15 W IRK.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0564
..THOMPSON..04/27/26
ATTN...WFO...TOP...EAX...SGF...
STATUS REPORT FOR WS 156
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
KSC107-121-271340-
KS
. KANSAS COUNTIES INCLUDED ARE
LINN MIAMI
MOC013-015-037-039-041-053-083-089-101-107-115-121-141-159-175-
185-195-217-271340-
MO
. MISSOURI COUNTIES INCLUDED ARE
BATES BENTON CASS
CEDAR CHARITON COOPER
HENRY HOWARD JOHNSON
LAFAYETTE LINN MACON
MORGAN PETTIS RANDOLPH
ST. CLAIR SALINE VERNON
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
Read more
MD 0565 CONCERNING SEVERE THUNDERSTORM WATCH 156...157... FOR EASTERN/NORTHERN MISSOURI AND SOUTHERN ILLINOIS
Mesoscale Discussion 0565
NWS Storm Prediction Center Norman OK
0736 AM CDT Mon Apr 27 2026
Areas affected...Eastern/northern Missouri and southern Illinois
Concerning...Severe Thunderstorm Watch 156...157...
Valid 271236Z - 271400Z
The severe weather threat for Severe Thunderstorm Watch 156, 157
continues.
SUMMARY...Elevated storms will persist through mid morning into west
central and southern Illinois with the threat for large hail. A
separate MCS will spread eastward from WW #156 into WW #157.
DISCUSSION...Elevated storms continue in a zone of low-level warm
advection on the nose of a 50 kt low-level jet. This area has been
near the east edge of the destabilization aloft overnight, and this
trend should continue with storms into western and southern IL,
where large hail of 1-1.75 inches in diameter will be the main
threat.
Farther west, earlier supercells in KS/MO have evolved into multiple
line segments with occasional mesovortices. The strongest portions
of the line have been more north-south oriented, orthogonal to the
deep-layer shear vectors and with substantial streamwise vorticity
in the low levels. Embedded circulations will continue to be
possible, though the storms may slightly out pace northward
expansion of the surface warm sector and associated surface-based
buoyancy. An isolated mesovortex tornado could occur, but the
primary threats will remain damaging winds and large hail in the
near term.
..Thompson.. 04/27/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...ILX...LSX...SGF...EAX...
LAT...LON 38119068 38389265 38589297 39399222 39959206 40059126
40009095 39609044 38848874 38238800 36958860 36868917
38119068
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Read more
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.
Read more
SPC 1300Z Day 1 Outlook
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
Read more
Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0343 AM CDT Mon Apr 27 2026
Valid 301200Z - 051200Z
...DISCUSSION...
Medium-range guidance continues to indicate that the prevailing
split flow will evolve in a manner that maintains a broadly
confluent regime across and east of the Rockies through this period.
Within the northern branch, it appears that a fairly significant low
will form within broad troughing overspreading the Northeast by
early next weekend, perhaps trailed by another developing low across
parts of the Upper Midwest/Great Lakes by early next week. At the
same time, an initially prominent subtropical high centered over
southern Mexico is forecast to become suppressed, as a mid/upper low
emanating from the subtropical eastern Pacific is forced eastward
into and through the confluent regime across the southern tier of
the United States.
It still appears that the shearing subtropical impulse, and perhaps
a trailing perturbation, will be preceded by broad cool surface
ridging overspreading much of the central and eastern U.S., as far
south as the Gulf Coast region by Thursday. The frontal zone on the
leading edge of this air mass is generally forecast to progress into
the Gulf Basin and Florida Peninsula, where it is likely to linger
through early next week. While forcing for ascent and
destabilization might support increasing thunderstorm development
across parts of central and southern Texas late this work week
(mostly above/to the cool side of the stalling frontal zone) into
Florida and adjacent portions of the Southeast by late next weekend,
the risk for severe weather still appears relatively minor at this
time.
Read more
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