Alert archive / Illinois / Tornado Warnings in 2025

Tornado Warning 2, NWS Quad Cities, IA

April 20, 2025Henderson County, Mercer County, Illinois; Des Moines County, Louisa County, Iowa

NWS Quad Cities, IA issued this tornado warning at Apr 20, 2025, 7:33 PM CDT for Henderson County, Mercer County, Illinois; Des Moines County, Louisa County, Iowa. It was in force for 42 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: Apr 20, 2025, 7:33 PM CDT (00:33 UTC)
Expired: Apr 20, 2025, 8:15 PM CDT
In force: 42 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Des Moines County, IA, Louisa County, IA, Henderson County, IL, Mercer County, IL

The radar

The Quad Cities radar (KDVN), 58 km from the middle of the area, began a volume at 00:37 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

Time	Report	Where	Remark
Apr 20, 7:45 PM CDT	TORNADO	2 N New Boston, IL	EF0...Peak Winds 85 MPH...Path Length 0.8 miles...Path Width 25 yards.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 20, 3:41 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.6 hours before the alert went out and 62 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 716 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 628 m²/s²
0-3 km storm-relative helicity: 711 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted.

364 
WFUS53 KDVN 210033
TORDVN
ILC071-131-IAC057-115-210115-
/O.NEW.KDVN.TO.W.0002.250421T0033Z-250421T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
733 PM CDT Sun Apr 20 2025

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  North central Henderson County in west central Illinois...
  Central Mercer County in northwestern Illinois...
  Northeastern Des Moines County in southeastern Iowa...
  Southeastern Louisa County in southeastern Iowa...

* Until 815 PM CDT.

* At 733 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Kingston, or near Oquawka, moving northeast at 40
  mph.

  HAZARD...Tornado.

  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.

* This dangerous storm will be near...
  Ogle, New Boston, Oakville, Keithsburg, Seaton, Big River State 
  Forest, and 4th Pumping Station Campground around 740 PM CDT.
  Mannon and Joy around 745 PM CDT.
  Petersville, Millersburg, Aledo, and Mercer County Fairgrounds 
  around 750 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Marston, Eliza, Aledo Mercer County Airport, Gingle Corners and
Hamlet.

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.

&&

LAT...LON 4098 9109 4133 9097 4133 9064 4132 9060
      4093 9096
TIME...MOT...LOC 0033Z 205DEG 34KT 4101 9101 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Gunkel

2 follow-up statements

084 
WWUS53 KDVN 210046
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
746 PM CDT Sun Apr 20 2025

ILC071-131-IAC057-115-210115-
/O.CON.KDVN.TO.W.0002.000000T0000Z-250421T0115Z/
Henderson IL-Mercer IL-Des Moines IA-Louisa IA-
746 PM CDT Sun Apr 20 2025

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR NORTH
CENTRAL HENDERSON...CENTRAL MERCER...NORTHEASTERN DES MOINES AND
SOUTHEASTERN LOUISA COUNTIES...

At 746 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Keithsburg, or 11 miles southwest of Aledo, moving
northeast at 40 mph.

HAZARD...Tornado.

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.

This dangerous storm will be near...
  Petersville, Mannon, New Boston, Millersburg, Joy, Aledo, and 
  Mercer County Fairgrounds around 750 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Marston, Eliza, Aledo Mercer County Airport, Gingle Corners, Hamlet
and Reynolds.

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.

&&

LAT...LON 4133 9097 4133 9064 4132 9060 4103 9092
      4109 9105
TIME...MOT...LOC 0046Z 205DEG 34KT 4112 9094 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Gunkel

112 
WWUS53 KDVN 210057
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
757 PM CDT Sun Apr 20 2025

ILC071-IAC057-115-210106-
/O.CAN.KDVN.TO.W.0002.000000T0000Z-250421T0115Z/
Henderson IL-Des Moines IA-Louisa IA-
757 PM CDT Sun Apr 20 2025

...THE TORNADO WARNING FOR NORTH CENTRAL HENDERSON...NORTHEASTERN DES
MOINES AND SOUTHEASTERN LOUISA COUNTIES IS CANCELLED...

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

A Tornado Watch remains in effect until 1100 PM CDT for northwestern
Illinois.

&&

LAT...LON 4133 9097 4133 9064 4132 9060 4109 9085
      4118 9102
TIME...MOT...LOC 0056Z 270DEG 34KT 4119 9086 

$$

ILC131-210115-
/O.CON.KDVN.TO.W.0002.000000T0000Z-250421T0115Z/
Mercer IL-
757 PM CDT Sun Apr 20 2025

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR CENTRAL
MERCER COUNTY...

At 756 PM CDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located over
Joy, or near Aledo, moving east at 40 mph.

HAZARD...Tornado.

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...
  Millersburg, Gingle Corners, Aledo Mercer County Airport, Aledo, 
  and Mercer County Fairgrounds around 800 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.

&&

LAT...LON 4133 9097 4133 9064 4132 9060 4109 9085
      4118 9102
TIME...MOT...LOC 0056Z 270DEG 34KT 4119 9086 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Gunkel

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 7:00 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, McDonough	60 min
Apr 20, 7:14 PM CDT	Severe Thunderstorm Warning	DVN	Henderson, Mercer, Warren	61 min
Apr 20, 7:25 PM CDT	Severe Thunderstorm Warning	DVN	Mercer, Rock Island	65 min
Apr 20, 7:33 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, Henderson, McDonough, Warren	42 min
Apr 20, 7:37 PM CDT	Tornado Warning	DVN	Hancock, Henderson, McDonough, Warren	23 min
Apr 20, 7:55 PM CDT	Severe Thunderstorm Warning	DVN	McDonough, Mercer, Warren	65 min
Apr 20, 7:57 PM CDT	Tornado Warning	DVN	Warren	23 min
Apr 20, 8:00 PM CDT	Tornado Warning	DVN	Mercer, Rock Island	32 min
Apr 20, 8:08 PM CDT	Severe Thunderstorm Warning	DVN	Rock Island	67 min
Apr 20, 8:31 PM CDT	Severe Thunderstorm Warning	DVN	Henry	59 min
Apr 20, 8:36 PM CDT	Tornado Warning	DVN	Henry, Mercer	39 min
Apr 20, 8:52 PM CDT	Tornado Warning	DVN	Henry	34 min
Apr 20, 9:06 PM CDT	Tornado Warning Tornado observed	DVN	Henry, Rock Island, Whiteside	24 min
Apr 20, 9:14 PM CDT	Tornado Warning	DVN	Bureau, Henry, Whiteside	31 min
Apr 20, 7:49 PM CDT	Flash Flood Warning	DVN	Benton, Johnson, Linn	3 hr

Nearby

Tornado Warnings in Illinois, 2025 Tornado Warnings in Iowa, 2025 Every tornado warning in 2025 Tornadoes in 2025

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.