Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 108, NWS Lincoln, IL

September 7, 2021McLean County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Sep 7, 2021, 4:58 PM CDT for McLean County, Illinois. It was in force for 47 min. 3 reports 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: Sep 7, 2021, 4:58 PM CDT (21:58 UTC)
Expired: Sep 7, 2021, 5:45 PM CDT
In force: 47 min
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County McLean County, IL

The radar

The Lincoln radar (KILX), 78 km from the middle of the area, began a volume at 21:59 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
Sep 7, 5:05 PM CDT	TSTM WND DMG	Colfax, IL	LARGE HEALTHY TREE ABOUT 2 FT DIAMTER DOWN NEAR FIFER ST AND HYATT ST. TIME ESTIMATED BY RADAR.
Sep 7, 5:05 PM CDT	TSTM WND DMG	Colfax, IL	SEVERAL LARGE TREE LIMBS DOWN ON POWER LINES. DELAYED REPORT. TIME ESTIMATED BY RADAR.
Sep 7, 5:15 PM CDT	HAIL 1.75	Colfax, IL

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
Sep 7, 1:12 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.0 hours before the alert went out and 47 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: 1964 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 93 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

555 
WUUS53 KILX 072158 RRA
SVRILX
ILC113-072245-
/O.NEW.KILX.SV.W.0108.210907T2158Z-210907T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Lincoln IL
458 PM CDT Tue Sep 7 2021

The National Weather Service in Lincoln has issued a

* Severe Thunderstorm Warning for...
  Northeastern McLean County in central Illinois...

* Until 545 PM CDT.

* At 457 PM CDT, severe thunderstorms were located along a line
  extending from near Fairbury to near Lexington, moving southeast at
  40 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.

* Severe thunderstorms will be near...
  Colfax around 515 PM CDT.

Other locations in the path of these severe thunderstorms include
Saybrook.

This includes Interstate 55 between mile markers 173 and 182.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4062 8858 4061 8846 4040 8846 4040 8865
      4064 8893 4073 8858
TIME...MOT...LOC 2157Z 300DEG 33KT 4072 8849 4062 8885 

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

$$

Geelhart

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 7, 2:55 PM CDT	Special Weather Statement	ILX	Stark	20 min
Sep 7, 3:53 PM CDT	Severe Thunderstorm Warning	ILX	Marshall, Woodford	37 min
Sep 7, 4:22 PM CDT	Severe Thunderstorm Warning	ILX	McLean, Woodford	38 min
Sep 7, 4:58 PM CDT	Severe Thunderstorm Warning	ILX	McLean	47 min
Sep 7, 5:39 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, DeWitt, McLean, Piatt	36 min
Sep 7, 6:09 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Vermilion	51 min
Sep 7, 6:30 PM CDT	Special Weather Statement	ILX	Piatt	45 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.