Alert archive / Illinois / Tornado Warnings in 2026

Tornado Warning 69, NWS Quad Cities, IA

July 20, 2026Mercer County, Warren County, Illinois

NWS Quad Cities, IA issued this tornado warning at Jul 20, 2026, 12:36 PM CDT for Mercer County, Warren County, Illinois. It was in force for 39 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 20, 2026, 12:36 PM CDT (17:36 UTC)
Expired
Jul 20, 2026, 1:15 PM CDT
In force
39 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Mercer County, IL, Warren County, IL

The radar

The Quad Cities radar (KDVN), 69 km from the middle of the area, began a volume at 17:40 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Jul 20, 12:43 PM CDTTSTM WND DMG1 Ese Monmouth, ILMultiple 1-3 inch tree branches down, one of which broke a window. Time estimated from radar.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 5.6 hours before the alert went out and 197 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2026-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2026-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1093 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

707 
WFUS53 KDVN 201736
TORDVN
ILC131-187-201815-
/O.NEW.KDVN.TO.W.0069.260720T1736Z-260720T1815Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
1236 PM CDT Mon Jul 20 2026

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Northern Warren County in west central Illinois...
  Southeastern Mercer County in northwestern Illinois...

* Until 115 PM CDT.

* At 1236 PM CDT, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located
  along a line extending from near Burgess to Alexis to Lake Warren,
  moving southeast at 30 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* These dangerous storms will be near...
  Monmouth, North Henderson, Alexis, Coldbrook, Monmouth Municipal 
  Airport, and Gerlaw around 1240 PM CDT.
  Cameron around 1245 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4093 9079 4098 9079 4119 9062 4113 9044
      4081 9044
TIME...MOT...LOC 1736Z 312DEG 25KT 4113 9058 4107 9054 4097 9063 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Uttech
3 follow-up statements
629 
WWUS53 KDVN 201747
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1247 PM CDT Mon Jul 20 2026

ILC131-187-201815-
/O.CON.KDVN.TO.W.0069.000000T0000Z-260720T1815Z/
Warren IL-Mercer IL-
1247 PM CDT Mon Jul 20 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 115 PM CDT FOR
NORTHEASTERN WARREN AND SOUTHEASTERN MERCER COUNTIES...

At 1246 PM CDT, a severe squall line capable of producing both 
tornadoes and straight line wind damage was located along a line 
extending from North Henderson to near Coldbrook to near Cameron, 
moving southeast at 35 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

These dangerous storms will be near...
  North Henderson, Coldbrook, and Cameron around 1250 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4090 9070 4107 9066 4117 9057 4113 9044
      4081 9044
TIME...MOT...LOC 1746Z 315DEG 30KT 4109 9050 4098 9051 4089 9058 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Uttech
392 
WWUS53 KDVN 201757
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1257 PM CDT Mon Jul 20 2026

ILC131-201807-
/O.CAN.KDVN.TO.W.0069.000000T0000Z-260720T1815Z/
Mercer IL-
1257 PM CDT Mon Jul 20 2026

...THE TORNADO WARNING FOR SOUTHEASTERN MERCER COUNTY IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

&&

LAT...LON 4087 9061 4103 9060 4106 9059 4107 9049
      4106 9044 4081 9044
TIME...MOT...LOC 1757Z 308DEG 34KT 4104 9043 4093 9044 4084 9051 

$$

ILC187-201815-
/O.CON.KDVN.TO.W.0069.000000T0000Z-260720T1815Z/
Warren IL-
1257 PM CDT Mon Jul 20 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 115 PM CDT FOR
NORTHEASTERN WARREN COUNTY...

At 1257 PM CDT, a severe squall line capable of producing both 
tornadoes and straight line wind damage was located along a line 
extending from near North Henderson to Galesburg Municipal Airport 
to near Cameron, moving southeast at 40 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

These tornadic storms will remain over mainly rural areas of
northeastern Warren County, including the following locations...
Gerlaw, Coldbrook, Cameron, and Alexis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4087 9061 4103 9060 4106 9059 4107 9049
      4106 9044 4081 9044
TIME...MOT...LOC 1757Z 308DEG 34KT 4104 9043 4093 9044 4084 9051 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Uttech
110 
WWUS53 KDVN 201812
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
112 PM CDT Mon Jul 20 2026

ILC187-201821-
/O.EXP.KDVN.TO.W.0069.000000T0000Z-260720T1815Z/
Warren IL-
112 PM CDT Mon Jul 20 2026

...THE TORNADO WARNING FOR NORTHEASTERN WARREN COUNTY WILL EXPIRE AT
115 PM CDT...

The storms which prompted the warning have weakened below severe 
limits and have moved out of the area. Therefore, the warning will 
be allowed to expire. However, gusty winds are still possible.

&&

LAT...LON 4087 9061 4103 9060 4106 9059 4107 9049
      4106 9044 4081 9044
TIME...MOT...LOC 1811Z 312DEG 25KT 4101 9038 4090 9039 4081 9046 

$$

Uttech

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Quad Cities, IA wrote its last area forecast discussion before this tornado warning went out at Jul 20, 6:27 AM CDT, 6 hours 9 minutes earlier. Its key messages:

  • Strong to severe storms are expected today and tonight with a morning round followed by a late afternoon/overnight round. The Storm Prediction Center has an enhanced, level 3 out 5, risk for severe storms along/north of I-80. South of I-80 a slight, level 2 out of 5, risk for severe storms exist.
  • Humid conditions will be seen across the area today with parts of the area seeing peak heat indices of 95 to 100. A heat advisory remains in effect for areas to the west and southwest of the Quad Cities for peak heat indices up to 105 degrees.
  • Smoke from Canadian wildfires keep hazy skies and poor air quality through tonight. The hazy skies may or may not persist past tonight.
Area forecast discussion, Jul 20, 6:27 AM CDT, 6 hours 9 minutes before
Area Forecast Discussion
National Weather Service Quad Cities IA IL
627 AM CDT Mon Jul 20 2026

.KEY MESSAGES...

- Strong to severe storms are expected today and tonight with a
  morning round followed by a late afternoon/overnight round.
  The Storm Prediction Center has an enhanced, level 3 out 5,
  risk for severe storms along/north of I-80. South of I-80 a
  slight, level 2 out of 5, risk for severe storms exist.

- Humid conditions will be seen across the area today with parts
  of the area seeing peak heat indices of 95 to 100. A heat
  advisory remains in effect for areas to the west and southwest
  of the Quad Cities for peak heat indices up to 105 degrees.

- Smoke from Canadian wildfires keep hazy skies and poor air
  quality through tonight. The hazy skies may or may not persist
  past tonight.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 241 AM CDT Mon Jul 20 2026

The first of two rounds of storms will arrive by 9 AM, possibly an
hour earlier, in the form of a decaying storm complex. The very
short term models indicate most of these storms should be sub-severe
with brief downpours and winds gusting up to 35 mph. HOWEVER, a
rogue severe storm cannot be ruled out with the energy potential in
the atmosphere.

The somewhat good news is that the morning round of storms will help
suppress temperatures and dew points which will keep heat indices in
the 95 to 100 range outside of the current heat advisory.

Areas that do not see any rain this morning will turn hot and humid
by mid-day. The current temporal/areal coverage of the heat
headlines looks good. We will SPS the remainder of the area for heat
indices of 95-100 with a mention that some areas adjacent to the
heat headlines may see heat indices exceed 100 for a couple of hours.

Boundaries left over from the morning convection will combine with
diurnal heating to provide areas for new convection mid to late
afternoon. The strengthening winds aloft combined with the arrival
of the cold front will allow the initial discrete cells to quickly
grow upscale into one or two bowing line segments.

During the discrete storm cell phase, all severe modes will be
possible. Once the individual storms grow upscale into bowing lines,
damaging winds, potentially 75+ mph, become the primary risk with
brief spin-up tornadoes a secondary risk.

Peak areal coverage of storms should occur between 4 PM and 1 AM
with a slow decrease the remainder of the night.

After 1 AM storms will slowly decay as the cold front pushes them
south of the area. Isolated strong to severe storms will still be
possible.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 241 AM CDT Mon Jul 20 2026

Tuesday through Thursday...some lingering early morning showers or
storms are possible in the far south as the cold front moves into
southern Missouri. Humid conditions will be seen Tuesday until a
secondary front moves through. Once this front moves through much
less humid conditions and cooler temperatures will be seen Wednesday
and Thursday.

Thursday night/Friday
Assessment...low (<25%) confidence on rain chances

The model consensus is narrowing the time frame for rain to late
Thursday night into Friday morning. Rain chances have increased
slightly (20-35%) mainly south of I-80 but this appears to be an
anomaly tied to one specific model.

The weak low and associated fronts are progged to be across Missouri
so the better rain chances will be associated with the higher
moisture and stronger forcing. Indeed, a dprog/Dt of the various
models shows a southward shift to the moisture/wind convergence;
closer to the frontal boundary. This adds support that the uptick in
rain chances is an anomaly. I suspect rain chances will slowly
decrease as the week progresses.

Friday night through Sunday
Assessment...a certainty (>98%) of slowly rising humidity levels

All models show southerly flow redeveloping over next weekend as the
heat dome builds north in the Plains. Dew points in the 50s Friday
night will slowly climb into the low to mid 60s Saturday with mid to
upper 60s dew points by Sunday. The increasing temperatures and
moisture will slowly push heat indices into the 90s by Sunday.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 623 AM CDT Mon Jul 20 2026

MVFR visibilities from wildfire smoke will continue through at
least 18z/20 across eastern Iowa and northern Illinois. A
convective complex will arrive after 12z that may produce brief
periods of IFR conditions. Boundaries from this complex
combined with daytime heating and the approaching cold front
will aid in developing convection after 20z/20 that is expected
to rapidly grow into lines that impact eastern Iowa and northern
Illinois through 06z/21 and potentially 12z/21. Thunderstorms
this evening will be very strong, with LIFR brief visibilities
with rain and hail, and gusty winds over 40kt. Some storms may
be able to push 60kt winds this evening.

Overnight, dry air will arriving behind a cold front, with
northwest winds and mainly VFR visibilities.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Heat Advisory from noon today to 8 PM CDT this evening for
     IAZ051-063-076>078-087>089-098-099.
IL...Heat Advisory from noon today to 8 PM CDT this evening for
     ILZ025-034.
     Air Quality Alert until midnight CDT tonight for ILZ001-002-
     007-009-015>018-024>026-034-035.
MO...Heat Advisory from noon today to 8 PM CDT this evening for
     MOZ009-010.

&&

SHORT TERM...08
LONG TERM...08
AVIATION...Ervin
Hazardous weather outlook, Jul 20, 3:21 AM CDT, 9 hours 15 minutes before
Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
321 AM CDT Mon Jul 20 2026

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-210830-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
321 AM CDT Mon Jul 20 2026

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TODAY AND TONIGHT

Hot and humid conditions are expected today with peak heat index
readings between 95 to 105 degrees. A Heat Advisory has been
issued for portions of the outlook area, west and southwest of the
Quad Cities.

Thunderstorms will be seen today in two rounds; one during the
morning and the second, more widespread round late this afternoon
and into tonight.

The Storm Prediction Center has an enhanced, level 3 out of 5,
risk of severe storms along and north of Interstate 80. South of
Interstate 80, a slight, level 2 out of 5, risk of severe storms
exists.

The morning round of storms will be mainly non-severe, but, an
isolated severe storm with gusty winds cannot be ruled out.

The late afternoon and evening round of storms are expected to be
strong to severe. When this round of storms develops, all modes
of severe weather are possible with supercells, including
tornadoes. As the storms quickly grow upscale into organized
clusters, the main severe risk will transition to damaging winds,
potentially over 75 mph, with brief spin-up tornadoes as a
secondary risk.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is expected this afternoon and evening.

In the hours before

Local storm report, Jul 20, 12:02 PM CDT, 34 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
1202 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1155 AM     Rain             3 W Center Junction     42.11N 91.14W
07/20/2026  M3.44 Inch       Jones              IA   Public

&&

arg
Local storm report, Jul 20, 12:06 PM CDT, 30 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
1206 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1203 PM     Rain             3 E Cedar Rapids        41.97N 91.61W
07/20/2026  M1.09 Inch       Linn               IA   Trained Spotter

            AM storms total.

1153 AM     Rain             Iowa City Municipality  41.63N 91.55W
07/20/2026  M1.49 Inch       Johnson            IA   Trained Spotter

            Morning storms total.

&&
Local storm report, Jul 20, 12:13 PM CDT, 23 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
1213 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1210 PM     Rain             2 NW North Liberty      41.76N 91.62W
07/20/2026  M1.24 Inch       Johnson            IA   Trained Spotter

&&

ALE
Local storm report, Jul 20, 12:26 PM CDT, 10 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
1226 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1221 PM     Tstm Wnd Gst     2 NNE Aledo             41.22N 90.73W
07/20/2026  M57 MPH          Mercer             IL   Mesonet

&&

arg
Local storm report, Jul 20, 12:29 PM CDT, 7 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
1229 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1225 PM     Rain             1 WNW Credit Island     41.51N 90.63W
07/20/2026  M3.53 Inch       Scott              IA   Public

            Multiple reports of one hour rainfall
            between 3 and 3.6 inches across west
            Davenport.

&&

MBS
Local storm report, Jul 20, 12:32 PM CDT, 4 minutes before
Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
1232 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1231 PM     Rain             2 E Taylor Ridge        41.39N 90.62W
07/20/2026  M3.05 Inch       Rock Island        IL   Public

            One hour precipitation.

&&

MBS

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 20, 11:25 AM CDTSpecial Weather StatementDVNRock Island50 min
Jul 20, 11:43 AM CDTSpecial Weather StatementDVNMercer47 min
Jul 20, 11:52 AM CDTSevere Thunderstorm WarningDVNHenderson, Henry, Mercer, Rock Island, Warren53 min
Jul 20, 12:20 PM CDTFlash Flood WarningDVNRock Island2 hr
Jul 20, 1:18 PM CDTSpecial Weather StatementDVNMcDonough42 min

Nearby

Tornado Warnings in Illinois, 2026Every tornado warning in 2026Tornadoes in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.