Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 98, NWS Lincoln, IL

August 25, 2021Knox County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Aug 25, 2021, 4:10 PM CDT for Knox County, Illinois. It was in force for 50 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: Aug 25, 2021, 4:10 PM CDT (21:10 UTC)
Expired: Aug 25, 2021, 5:00 PM CDT
In force: 50 min
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Damage threat: Considerable
Hail: 1.75 in
Wind: 60.0 mph

County Knox County, IL

The radar

The Quad Cities radar (KDVN), 67 km from the middle of the area, began a volume at 21:12 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
Aug 25, 4:27 PM CDT	TSTM WND GST 60	2 N Altona, IL

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

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.2 hours before the alert went out and 64 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: 818 J/kg
Mixed-layer CIN: -238 J/kg
Mixed-layer LCL: 1355 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -32 m²/s²
0-3 km storm-relative helicity: -10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

235 
WUUS53 KILX 252110
SVRILX
ILC095-252200-
/O.NEW.KILX.SV.W.0098.210825T2110Z-210825T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Lincoln IL
410 PM CDT Wed Aug 25 2021

The National Weather Service in Lincoln has issued a

* Severe Thunderstorm Warning for...
  Northern Knox County in west central Illinois...

* Until 500 PM CDT.

* At 410 PM CDT, a severe thunderstorm was located near Cambridge,
  moving east at 15 mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Altona around 420 PM CDT.

This includes Interstate 74 between mile markers 34 and 41.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4115 8998 4103 8999 4105 9040 4115 9038
TIME...MOT...LOC 2110Z 283DEG 12KT 4121 9018 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MJA

3 follow-up statements

739 
WWUS53 KILX 252135
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
435 PM CDT Wed Aug 25 2021

ILC095-252200-
/O.CON.KILX.SV.W.0098.000000T0000Z-210825T2200Z/
Knox-
435 PM CDT Wed Aug 25 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR NORTHEASTERN KNOX COUNTY...

At 435 PM CDT, a severe thunderstorm was located over Altona, or 12
miles south of Cambridge, moving east at 15 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...At 4:30 PM CDT, law enforcement reported 60 mph wind gusts 
         just north of Altona.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
  Altona and Victoria.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4105 9032 4115 9031 4115 8998 4103 8999
TIME...MOT...LOC 2135Z 276DEG 12KT 4113 9022 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MJA

989 
WWUS53 KILX 252145
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
445 PM CDT Wed Aug 25 2021

ILC095-252200-
/O.CON.KILX.SV.W.0098.000000T0000Z-210825T2200Z/
Knox-
445 PM CDT Wed Aug 25 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR NORTHEASTERN KNOX COUNTY...

At 444 PM CDT, a severe thunderstorm was located over Altona, or 12
miles south of Cambridge, moving east at 20 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Oneida, Altona and Victoria. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4105 9027 4115 9023 4115 8998 4103 8999
TIME...MOT...LOC 2144Z 283DEG 12KT 4112 9018 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MJA

536 
WWUS53 KILX 252154
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
454 PM CDT Wed Aug 25 2021

ILC095-252204-
/O.EXP.KILX.SV.W.0098.000000T0000Z-210825T2200Z/
Knox-
454 PM CDT Wed Aug 25 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KNOX COUNTY WILL
EXPIRE AT 500 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

LAT...LON 4105 9027 4115 9023 4115 8998 4103 8999
TIME...MOT...LOC 2154Z 283DEG 12KT 4112 9017 

$$

MJA

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 24, 7:26 PM CDT	Special Weather Statement	ILX	Knox, Stark	64 min
Aug 24, 8:00 PM CDT	Special Weather Statement	ILX	Knox, Marshall, Peoria, Stark	60 min
Aug 24, 8:28 PM CDT	Special Weather Statement	ILX	Peoria, Tazewell, Woodford	47 min
Aug 24, 8:43 PM CDT	Severe Thunderstorm Warning	ILX	Fulton, McLean, Mason, Peoria, Tazewell, Woodford	47 min
Aug 24, 9:10 PM CDT	Special Weather Statement	ILX	DeWitt, Logan, McLean	50 min
Aug 24, 9:45 PM CDT	Special Weather Statement	ILX	DeWitt, Macon, Menard, Piatt, Sangamon	30 min
Aug 24, 10:18 PM CDT	Special Weather Statement	ILX	Christian, Macon, Moultrie, Piatt	57 min
Aug 24, 10:36 PM CDT	Special Weather Statement	ILX	Champaign, Vermilion	54 min
Aug 24, 11:05 PM CDT	Special Weather Statement	ILX	Christian, Coles, Douglas, Moultrie, Shelby	40 min
Aug 25, 4:15 PM CDT	Special Weather Statement	ILX	Edgar	45 min
Aug 25, 4:33 PM CDT	Special Weather Statement	ILX	Vermilion	42 min
Aug 25, 4:42 PM CDT	Severe Thunderstorm Warning	ILX	Stark	33 min
Aug 25, 4:51 PM CDT	Severe Thunderstorm Warning	ILX	Fulton, Knox	24 min
Aug 25, 5:22 PM CDT	Special Weather Statement	ILX	Peoria	53 min
Aug 25, 6:11 PM CDT	Severe Thunderstorm Warning	ILX	Peoria, Tazewell	34 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2021 Every severe thunderstorm warning in 2021

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.