WW 311 TORNADO IA IL MO 111230Z - 112000Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 311
NWS Storm Prediction Center Norman OK
730 AM CDT Thu Jun 11 2026
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Southern and Eastern Iowa
Northwest Illinois
Far northern Missouri
* Effective this Thursday morning and afternoon from 730 AM until
300 PM CDT.
* Primary threats include...
A few tornadoes and a couple intense tornadoes possible
Widespread damaging winds likely with isolated significant gusts
to 80 mph possible
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
SUMMARY...A well-organized and intense bowing linear system will
continue eastward this morning with the potential for widespread
damaging winds and potentially an increasing tornado risk, with the
intense convective line as well as any storms developing ahead of
it.
The tornado watch area is approximately along and 90 statute miles
north and south of a line from Knoxville IA to 40 miles east
southeast of Moline IL. 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 310...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 70 knots. A few cumulonimbi with maximum tops to 600. Mean
storm motion vector 27045.
...Guyer
WW 0311 Status Updates
STATUS REPORT ON WW 311
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNE CDJ
TO 35 SW OTM TO 10 SSW OTM TO 35 E OTM TO 20 SSE CID TO 25 NNE
CID TO 25 WSW DBQ TO 40 NW DBQ.
..JIRAK..06/11/26
ATTN...WFO...DMX...DVN...LSX...ILX...EAX...
STATUS REPORT FOR WT 311
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC001-009-011-015-057-067-071-073-085-095-109-123-131-143-155-
161-169-175-177-187-195-111640-
IL
. ILLINOIS COUNTIES INCLUDED ARE
ADAMS BROWN BUREAU
CARROLL FULTON HANCOCK
HENDERSON HENRY JO DAVIESS
KNOX MCDONOUGH MARSHALL
MERCER PEORIA PUTNAM
ROCK ISLAND SCHUYLER STARK
STEPHENSON WARREN WHITESIDE
IAC007-031-045-051-057-061-087-097-101-103-105-111-113-115-139-
163-177-179-183-111640-
IA
. IOWA COUNTIES INCLUDED ARE
APPANOOSE CEDAR CLINTON
DAVIS DES MOINES DUBUQUE
HENRY JACKSON JEFFERSON
WW 0310 Status Updates
STATUS REPORT ON WW 310
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 N STJ TO
40 ESE SDA TO 30 NW LWD TO 35 NNW LWD TO 30 WSW DSM TO 45 SSW FOD
TO 40 SSW FOD TO 15 WNW FOD.
..WENDT..06/11/26
ATTN...WFO...DMX...OAX...EAX...GID...
STATUS REPORT FOR WS 310
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IAC007-013-015-039-049-051-053-073-075-079-083-099-117-121-123-
125-127-135-153-157-159-169-171-179-181-185-187-111340-
IA
. IOWA COUNTIES INCLUDED ARE
APPANOOSE BLACK HAWK BOONE
CLARKE DALLAS DAVIS
DECATUR GREENE GRUNDY
HAMILTON HARDIN JASPER
LUCAS MADISON MAHASKA
MARION MARSHALL MONROE
POLK POWESHIEK RINGGOLD
STORY TAMA WAPELLO
WARREN WAYNE WEBSTER
MOC075-081-129-147-171-197-227-111340-
MO
. MISSOURI COUNTIES INCLUDED ARE
GENTRY HARRISON MERCER
NODAWAY PUTNAM SCHUYLER
MD 1086 CONCERNING TORNADO WATCH 311... FOR EASTERN IOWA INTO NORTHWEST ILLINIOIS AND NORTHEAST MISSOURI
Mesoscale Discussion 1086
NWS Storm Prediction Center Norman OK
0953 AM CDT Thu Jun 11 2026
Areas affected...eastern Iowa into northwest Illiniois and northeast
Missouri
Concerning...Tornado Watch 311...
Valid 111453Z - 111630Z
The severe weather threat for Tornado Watch 311 continues.
SUMMARY...Severe wind gusts remain likely across eastern Iowa,
northwest Illinois, and northeast Missouri. A tornado risk may
develop from northeast Missouri into west-central Illinois.
DISCUSSION...An MCS with a history of producing measured severe wind
gusts continues to quickly move across eastern IA. Two main surges
are evident within this north-south line, with the southeast IA
portion currently stronger than the section moving into northeast
IA. Meanwhile, a trailing portion of the MCS extends southwestward
into northern MO, where backbuilding is occurring.
It appears the environment farther east across IL and southern WI
will need to undergo significant destabilization for this existing
MCS to remain severe into the afternoon. 12Z soundings from DVN and
ILX show a stabilized air mass from the overnight MCS, with GPS PWAT
sensors indicating a deeper moisture gradient across central IL.
However, visible satellite shows strong heating occurring ahead of
the MCS, and modest southwest winds will allow for moisture to
gradually return northward across IL and vicinity.
Some tornado risk exists as well, especially along the
southern/southeastern fringe of the MCS. Here, 0-1 km SRH will
remain strongest, and the environment should become more favorable
later in the day as the air mass become more volatile.
..Jewell/Gleason.. 06/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...ILX...LSX...DVN...DMX...EAX...
LAT...LON 39808969 39639044 39979227 40059298 40639244 40879182
41159148 41669130 42039116 42169119 42008980 41958974
41838906 41328882 40858895 39808969
MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK WIND GUST...55-70 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
0830 AM CDT THU JUN 11 2026
...Outbreak of severe thunderstorms expected over parts of the
Midwest and Great Lakes today...
* LOCATIONS...
Northern and Central Illinois
Northern and Eastern Missouri
Eastern Iowa
Southern and Eastern Wisconsin
Northwest Indiana
Lower Michigan
* HAZARDS...
Widespread damaging winds, some hurricane force
Several tornadoes, a couple intense
Isolated large hail up to baseball size
* SUMMARY...
Widespread severe thunderstorms are expected today across parts
of the Midwest and Great Lakes region, including Iowa, northern
Missouri, northern Illinois and southern Wisconsin to Lower
Michigan and northern Indiana. This includes the potential for
widespread/intense damaging winds, large hail, and tornadoes,
some of which may be strong to intense.
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 watch
means that conditions are favorable for severe thunderstorms
over the next several hours. If a severe thunderstorm warning is
issued for your area, move to a place of safety, ideally in an
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
0758 AM CDT Thu Jun 11 2026
Valid 111300Z - 121200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
IOWA AND NORTHERN ILLINOIS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHEAST/MID-ATLANTIC STATES...
...SUMMARY...
Widespread severe thunderstorms are expected across parts of the
Midwest and Great Lakes region, including Iowa, northern Missouri,
northern Illinois and southern Wisconsin to Lower Michigan and
northern Indiana. This includes the potential for widespread/intense
damaging winds, large hail, and tornadoes, some of which may be
strong.
...Midwest/Great Lakes...
Portions of the region have been upgraded to a Moderate Risk.
Another very active day with widespread/intense severe storms is
expected regionally. A consequential severe risk is already ongoing
this morning across Iowa/far northern Missouri, and will continue
east-northeastward and become more prominent regionally during the
day. A well-organized/eastward-accelerating bowing cluster of
storms, now supported by an apparent MCV, has had a history of
measured severe-caliber wind gusts overnight and in the predawn
hours from southeast Nebraska into southern Iowa. A similar severe
risk should continue east-northeastward through midday across
eastern Iowa/far northeast Missouri toward northern Illinois, with
more of a surface-based/tornado risk potentially unfolding
relatively early today aside from a continued prominent damaging
wind threat.
Scenario is supported by a robust southwesterly low-level
jet/moisture transport, even with some diurnal weakening of the
low-level jet possible. Also influential is a prominent/increasingly
neutral-tilt-shortwave trough and jet streak crossing the Corn Belt,
notably strong features by mid-June standards.
Convective overturning/outflow from last evening's MCS are still
residual factors evident this morning in observational
data/supplemental 3D mesoanalysis across far eastern Iowa, far
northeast Missouri into central Illinois. This is sampled by the 12z
observed sounding from KILX/Lincoln, IL. These residual factors may
somewhat southward-focus the peak/most-intense severe weather later
today, with more uncertainty progressively northward in general
proximity to Lake Michigan latitudinally, including parts of
Wisconsin/Michigan. The timing/residual impacts of this morning's
MCS across Iowa/northern Missouri into northern Illinois and severe
potential in its wake near the surface low and front, and/or to its
(MCS) north-northeast are a bit less uncertain. That said, mass
response/fluxes related to the dynamic shortwave trough/speed max
will be notable and consistent with heightened severe-potential even
if outflow/cloud debris exists and sub-regional areas of
destabilization are sub-optimal.
Details of later-afternoon severe potential is somewhat contingent
on how the morning MCS further evolves, but a window for
redevelopment in its immediate wake will probably exist. This will
lead to a renewed round of severe storms as development occurs near
the cold front, and perhaps preferentially favors prior outflow,
with a damaging wind and tornado risk continuing eastward this
evening as the low-level jet re=intensifies and as storms gradually
grow upscale toward Lake Michigan and across Illinois/Indiana/Lower
Michigan.
...Eastern Kansas and Southern Plains...
Additional thunderstorm development is expected along the trailing
cold front into portions of the central/southern Plains. Deep layer
shear will be maximized in the post-frontal environment; however,
around 20-30 kt of effective bulk shear and moderate to strong
instability will support some supercell structures capable of large
hail and damaging winds. Storm motions and boundary parallel shear
will likely lead to clustering and messy modes over time.
...Mid-Atlantic ad central Appalachians...
Forcing for ascent from multiple shortwave disturbances across the
northeast and dewpoints in the 60s to 70s F will support development
of widely scattered thunderstorms by afternoon across the
Mid-Atlantic into the central Appalachians. Though vertical shear
will be generally weak, moderate to strong instability will be in
place will support stronger updrafts capable of damaging winds. It
is likely that several clusters will emerge with potential for
organizing along cold pools and more focused corridors of damaging
wind potential.
..Guyer/Wendt.. 06/11/2026
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