Alert archive / Illinois / Flash Flood Warnings in 2021

Flash Flood Warning 23, NWS Lincoln, IL

July 16, 2021McLean County, Illinois

NWS Lincoln, IL issued this flash flood warning at Jul 16, 2021, 9:41 AM CDT for McLean County, Illinois. It was in force for 4 hr. 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 16, 2021, 9:41 AM CDT (14:41 UTC)
Expired: Jul 16, 2021, 1:30 PM CDT
In force: 4 hr
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Flood severity: None

County McLean County, IL

The radar

The Lincoln radar (KILX), 63 km from the middle of the area, began a volume at 14:41 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
Jul 16, 11:01 AM CDT	HEAVY RAIN 1.41	Arrowsmith, IL	MESONET STATION DW9547 ARROWSMITH.

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

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 2.7 hours before the alert went out and 30 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: 139 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 541 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

303 
WGUS53 KILX 161441
FFWILX
ILC113-161830-
/O.NEW.KILX.FF.W.0023.210716T1441Z-210716T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
941 AM CDT Fri Jul 16 2021

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  Southern McLean County in central Illinois...

* Until 130 PM CDT.

* At 938 AM CDT, Emergency management reported numerous roads closed 
  due to high water between Downs and Heyworth. Rain continues to 
  fall across the area, with Doppler radar indicating 3 to 5 inches 
  over the past 3 hours. Flash flooding is ongoing.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency management.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Le Roy, Heyworth, Downs, McLean, Saybrook, Arrowsmith, Ellsworth, 
  Holder and Moraine View State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other low lying 
spots.

&&

LAT...LON 4040 8846 4029 8900 4028 8915 4036 8920
      4054 8846 4050 8846 4049 8846 4047 8846

FLASH FLOOD...OBSERVED

$$

Barnes

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 7:35 PM CDT	Flash Flood Warning	ILX	Coles	4 hr
Jul 16, 7:04 AM CDT	Flash Flood Warning	ILX	McLean	4 hr
Jul 16, 7:16 AM CDT	River Flood Warning	ILX	Fulton, Knox	10 hr
Jul 16, 9:40 AM CDT	River Flood Warning	ILX	Crawford, Jasper	23 hr
Jul 16, 9:43 AM CDT	River Flood Warning	ILX	Lawrence	5 days
Jul 16, 11:37 AM CDT	Areal Flood Advisory	ILX	Cass, Fulton, Mason, Menard, Schuyler, Tazewell	3 hr
Jul 16, 1:35 PM CDT	Areal Flood Warning	ILX	DeWitt, Logan, McLean	24 hr
Jul 16, 5:47 PM CDT	Flash Flood Warning	ILX	Clay, Crawford, Effingham, Jasper, Lawrence, Richland	4 hr

Nearby

Flash Flood Warnings in Illinois, 2021 Every flash flood 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.