WW 158 SEVERE TSTM IL 271330Z - 272100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 158
NWS Storm Prediction Center Norman OK
830 AM CDT Mon Apr 27 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Central and Southern Illinois
* Effective this Monday morning and afternoon from 830 AM until
400 PM CDT.
* Primary threats include...
Scattered large hail likely with isolated very large hail events
to 2 inches in diameter possible
Scattered damaging wind gusts to 70 mph likely
A tornado or two possible
SUMMARY...A bowing linear cluster will continue to steadily move
eastward with additional development to its southeast. Large hail
and damaging winds are the primary concerns, especially as the air
mass continues to warm/destabilize across southern and central
Illinois through late morning and afternoon.
The severe thunderstorm watch area is approximately along and 55
statute miles north and south of a line from 20 miles north
northwest of Quincy IL to 40 miles east southeast of Mattoon IL. For
a complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU8).
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...WW 157...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
25030.
...Guyer
WW 0158 Status Updates
STATUS REPORT ON WW 158
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..HART..04/27/26
ATTN...WFO...LSX...ILX...DVN...
STATUS REPORT FOR WS 158
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC001-005-009-017-019-021-023-025-027-029-033-035-039-041-045-
049-051-057-067-079-101-107-109-113-115-117-121-125-129-135-137-
139-143-147-159-167-169-171-173-179-183-189-203-271540-
IL
. ILLINOIS COUNTIES INCLUDED ARE
ADAMS BOND BROWN
CASS CHAMPAIGN CHRISTIAN
CLARK CLAY CLINTON
COLES CRAWFORD CUMBERLAND
DE WITT DOUGLAS EDGAR
EFFINGHAM FAYETTE FULTON
HANCOCK JASPER LAWRENCE
LOGAN MCDONOUGH MCLEAN
MACON MACOUPIN MARION
MASON MENARD MONTGOMERY
MORGAN MOULTRIE PEORIA
PIATT RICHLAND SANGAMON
SCHUYLER SCOTT SHELBY
TAZEWELL VERMILION WASHINGTON
WOODFORD
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
WW 0157 Status Updates
STATUS REPORT ON WW 157
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 E UIN TO
30 SSE UIN TO 45 S UIN TO COU TO 5 SSE VIH TO 20 S FAM TO 35 ESE
POF.
..HART..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-
145-149-151-153-157-163-165-181-185-191-193-199-271540-
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
KYC007-035-039-075-083-105-139-145-157-271540-
KY
. KENTUCKY COUNTIES INCLUDED ARE
BALLARD CALLOWAY CARLISLE
FULTON GRAVES HICKMAN
WW 0156 Status Updates
STATUS REPORT ON WW 156
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 NE CNU TO
20 ESE SZL TO 10 WNW COU.
..HART..04/27/26
ATTN...WFO...TOP...EAX...SGF...
STATUS REPORT FOR WS 156
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MOC013-015-039-083-141-185-217-271540-
MO
. MISSOURI COUNTIES INCLUDED ARE
BATES BENTON CEDAR
HENRY MORGAN ST. CLAIR
VERNON
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
MD 0566 CONCERNING SEVERE THUNDERSTORM WATCH 156...157... FOR CENTRAL MISSOURI
Mesoscale Discussion 0566
NWS Storm Prediction Center Norman OK
0933 AM CDT Mon Apr 27 2026
Areas affected...Central Missouri
Concerning...Severe Thunderstorm Watch 156...157...
Valid 271433Z - 271630Z
The severe weather threat for Severe Thunderstorm Watch 156, 157
continues.
SUMMARY...The potential for isolated damaging winds and large hail
is expected to continue beyond the scheduled 15z expiration of
Severe Thunderstorm Watches 156 and 157. A local extension in time
may be required.
DISCUSSION...As of 14z, mosaic radar imagery indicated a leading bow
echo over west-central IL with trailing, outflow-dominant convection
bisecting I-70 across central MO. The 12z Springfield, MO sounding
indicated a very moist low-level air mass with a pronounced capping
inversion at the base of an elevated-mixed layer characterized by
700-500-mb lapse rates of 8.5 C/km.
Latest short-term model guidance suggests that the ongoing, trailing
convection across central MO will linger beyond the scheduled 15z
expiration of WWs 156 and 157. However, currently it appears that
the cold pool circulation is not sufficiently strong to overcome the
currently capping in place. Furthermore, the largely parallel
orientation of the line to the mid/upper-level flow will limit the
damaging wind potential. Nonetheless, the presence of strong
low-level and deep-layer shear will maintain at least an isolated
damaging wind and/or hail threat this morning.
..Mead.. 04/27/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LSX...SGF...EAX...
LAT...LON 37869439 38269444 38809293 39489177 39599062 38559023
38009041 37669279 37869439
MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
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.
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
|
