
Mesoscale Discussion 0486
NWS Storm Prediction Center Norman OK
0839 PM CDT Fri Apr 17 2026
Areas affected...parts of east central Missouri into adjacent
portions of Illinois
Concerning...Tornado Watch 131...
Valid 180139Z - 180345Z
The severe weather threat for Tornado Watch 131 continues.
SUMMARY...An organized cluster of storms may be maintained across
northwestern portions of Greater St. Louis through 9-11 PM CDT, with
a continuing risk for damaging wind gusts and potential for a brief
tornado or two.
DISCUSSION...A sustained cluster of thunderstorms has become
increasingly organized across and east of the Missouri Ozarks during
the past few hours, with a well-defined lower/mid-tropospheric
cyclonic circulation and associated evolving bow echo structure in
radar reflectivities. It appears that the apex of the bow structure
has accelerated east-northeastward in excess of 50 kt. If this
motion is maintained, it is on track to surge across northwestern
portions of Greater St. Louis through 02-03Z.
This still appears to be perhaps just ahead of the leading edge of
the surface cold front, as delineated by 2-4 mb 2-hourly surface
pressures rises now east of Quincy IL south/southwestward through
the Columbia and Sedalia vicinities. The boundary-layer has
undergone warming and drying across the St. Louis area, where the
temperature/dew point at Lambert is 81/57 F. However, thermodynamic
profiles still appear sufficiently unstable to maintain convection
with potential to produce damaging wind gusts. The risk for
tornadoes is more unclear, but the environment might still be
conducive immediately to the north of the front.
..Kerr.. 04/18/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ILX...LSX...SGF...
LAT...LON 38949180 39509044 39838933 39098870 38458965 38069075
38029216 38409185 38949180
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
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URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 133 NWS Storm Prediction Center Norman OK 1045 PM EDT Fri Apr 17 2026 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of West-Central and Northern Indiana Far Southeast Lower Michigan Lake Michigan * Effective this Friday night and Saturday morning from 1045 PM until 300 AM EDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible SUMMARY...A line of thunderstorms will pose a threat for scattered damaging winds and perhaps a couple of brief embedded tornadoes as it moves quickly east-northeastward late this evening into early Saturday morning before eventually weakening. The tornado watch area is approximately along and 30 statute miles east and west of a line from 25 miles north northeast of South Bend IN to 5 miles south southeast of Terre Haute IN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && OTHER WATCH INFORMATION...CONTINUE...WW 131...WW 132... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26045. ...GleasonRead more

STATUS REPORT ON WW 131 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 E SZL TO 35 SSE UIN TO 25 ENE SPI TO 10 N MMO TO 25 ENE MKE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0485 ..MOORE..04/18/26 ATTN...WFO...LSX...ILX...LOT... STATUS REPORT FOR WT 131 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-013-019-021-023-027-029-031-035-039-041-043-045-051-053- 061-063-075-083-091-093-097-105-113-115-117-119-121-133-135-139- 147-163-173-183-189-197-180340- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CALHOUN CHAMPAIGN CHRISTIAN CLARK CLINTON COLES COOK CUMBERLAND DE WITT DOUGLAS DUPAGE EDGAR FAYETTE FORD GREENE GRUNDY IROQUOIS JERSEY KANKAKEE KENDALL LAKE LIVINGSTON MCLEAN MACON MACOUPIN MADISON MARION MONROE MONTGOMERY MOULTRIE PIATT ST. CLAIR SHELBY VERMILION WASHINGTON WILL INC007-073-089-111-127-180340-Read more

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 131
NWS Storm Prediction Center Norman OK
330 PM CDT Fri Apr 17 2026
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Central and Northeast Illinois
Northeast Missouri
Lake Michigan
* Effective this Friday afternoon and evening from 330 PM until
1100 PM CDT.
* Primary threats include...
A couple tornadoes possible
Widespread damaging winds likely with isolated significant gusts
to 75 mph possible
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
SUMMARY...Thunderstorms have intensified across northeast MO, with
some additional intensification possible as they continued
northeastward into central IL. The airmass across the region
supports supercells capable of all severe hazards, including very
large hail and tornadoes. Another round of storms will follow in the
wake of the ongoing storms later this evening as a cold front moves
across the region. Wind gusts will be the primary risk with the
storms along the front, but line-embedded circulations are possible
as well.
The tornado watch area is approximately along and 75 statute miles
east and west of a line from 50 miles west northwest of Valparaiso
IN to 30 miles southeast of Jefferson City MO. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU1).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 128...WW 129...WW 130...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2.5 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 27030.
...Mosier
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URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 132
NWS Storm Prediction Center Norman OK
845 PM CDT Fri Apr 17 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Far Northwest Arkansas
Extreme Southeast Kansas
Southwest and South-Central Missouri
Northern, Central, and Western Oklahoma
* Effective this Friday night and Saturday morning from 845 PM
until 200 AM CDT.
* Primary threats include...
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
A tornado or two possible
SUMMARY...A mix of mainly elevated supercells and some bowing
clusters should continue to pose a threat for scattered large hail
and damaging winds through the early morning hours. A tornado
appears possible if a supercell can become surface based along/south
of the cold front; but, confidence in this occurring is low.
The severe thunderstorm watch area is approximately along and 40
statute miles north and south of a line from 45 miles west of
Clinton OK to 25 miles east southeast of Fort Leonard Wood MO. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU2).
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 130...WW 131...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
26040.
...Gleason
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Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Apr 17 2026 Valid 180100Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF ILLINOIS INTO NORTHEAST MISSOURI...AND OVER NORTHERN OKLAHOMA... ...SUMMARY... Damaging storms producing wind, hail and isolated tornadoes remain possible this evening from Illinois into Oklahoma. ...WI/MI into IL and MO... Supercells have largely merged into a broken line of assorted bows from far southeast WI across much of northern into western IL and trailing into northeast MO. The 00Z ILX sounding shows steep lapse rates aloft and large deep-layer shear, as well as veering winds with height. Low-level SRH will remain favorable for rotation to develop at least briefly anywhere within the line, with damaging winds the most likely threat. Storms have recently become better organized over central MO, and this activity may affect the St. Louis area later tonight. For lower MI into northern IN, the organized line of storms to the west along with a 60 kt low-level jet suggest at least isolated severe gusts may occur overnight despite lesser instability. For more information about Illinois, see mesoscale discussion 484. ...OK...Southeast KS...southwest MO...northwest AR... Scattered severe cells persist near and north of the cold front across much of northern OK and extending into southeast KS. Although the undercutting cold air will likely mitigate wind potential, steep lapse rates aloft along with ample deep-layer shear will continue to favor hail. Storm coverage may be more isolated into southwest OK later tonight, but the environment remains quite favorable for large hail. One corridor for possible damaging wind or even a tornado is over northeast OK into southwest MO. Here, the front is not surging as fast, and storms over Osage county are already oriented more favorably N-S relative to the deep-layer shear. A southwest low-level jet near 50 kt will further support low-level rotation. ..Jewell.. 04/18/2026Read more

STATUS REPORT ON WW 129 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ESE IRK TO 20 S MLI TO 25 WSW JVL TO 30 ENE MSN TO 10 SE MTW. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0484 ..MOORE..04/18/26 ATTN...WFO...ARX...DMX...DVN...LOT...MPX...GRB...MKX... STATUS REPORT FOR WT 129 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-011-037-067-071-073-099-103-109-111-141-155-187-195-201- 180140- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE BUREAU DE KALB HANCOCK HENDERSON HENRY LA SALLE LEE MCDONOUGH MCHENRY OGLE PUTNAM WARREN WHITESIDE WINNEBAGO WIC055-059-079-089-101-105-117-127-131-133-180140- WI . WISCONSIN COUNTIES INCLUDED ARE JEFFERSON KENOSHA MILWAUKEE OZAUKEE RACINE ROCK SHEBOYGAN WALWORTH WASHINGTON WAUKESHARead more

STATUS REPORT ON WW 130 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 N CSM TO 30 NNE PNC TO 10 NW CNU TO 55 S OJC. ..KERR..04/18/26 ATTN...WFO...ICT...TOP...EAX...DDC...SGF...OUN...TSA... STATUS REPORT FOR WT 130 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC001-011-019-021-035-037-049-099-125-133-205-180140- KS . KANSAS COUNTIES INCLUDED ARE ALLEN BOURBON CHAUTAUQUA CHEROKEE COWLEY CRAWFORD ELK LABETTE MONTGOMERY NEOSHO WILSON MOC011-013-015-029-039-041-053-083-085-089-101-121-125-131-141- 159-175-185-195-217-180140- MO . MISSOURI COUNTIES INCLUDED ARE BARTON BATES BENTON CAMDEN CEDAR CHARITON COOPER HENRY HICKORY HOWARD JOHNSON MACON MARIES MILLER MORGAN PETTIS RANDOLPH ST. CLAIR SALINE VERNONRead more