Alert archive / Illinois / Flash Flood Warnings in 2020

Flash Flood Warning 21, NWS Lincoln, IL

July 11, 2020Champaign County, Illinois

NWS Lincoln, IL issued this flash flood warning at Jul 11, 2020, 5:45 PM CDT for Champaign County, Illinois. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 11, 2020, 5:45 PM CDT (22:45 UTC)
Expired: Jul 11, 2020, 8:45 PM CDT
In force: 3 hr
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Flood severity: None

County Champaign County, IL

The radar

The Lincoln radar (KILX), 102 km from the middle of the area, began a volume at 22:45 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.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.8 hours before the alert went out and 40 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: 12 J/kg
Mixed-layer CIN: -285 J/kg
Mixed-layer LCL: 1580 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

864 
WGUS53 KILX 112245
FFWILX
ILC019-120145-
/O.NEW.KILX.FF.W.0021.200711T2245Z-200712T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
545 PM CDT Sat Jul 11 2020

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  Champaign County in east central Illinois...

* Until 845 PM CDT.

* At 543 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  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 flooding include...
  Champaign, Urbana, Savoy, Mahomet, St. Joseph, Tolono, Fisher,
  Philo, Sidney, Homer, Thomasboro, Ogden, Bondville, Broadlands,
  Allerton, Lake Of The Woods, Seymour, Royal, Longview and Foosland.

This includes the following highways...
 Interstate 57 between mile markers 225 and 248.
 Interstate 72 between mile markers 174 and 182.
 Interstate 74 between mile markers 169 and 197.

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, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3988 8804 4002 8846 4039 8846 4019 8794
      3988 8794

FLASH FLOOD...RADAR INDICATED

$$

25

1 follow-up statement

592 
WGUS73 KILX 120147
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
847 PM CDT Sat Jul 11 2020

ILC019-120156-
/O.EXP.KILX.FF.W.0021.000000T0000Z-200712T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Champaign-
847 PM CDT Sat Jul 11 2020

...THE FLASH FLOOD WARNING FOR CHAMPAIGN COUNTY HAS EXPIRED...

Flood waters have receded. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3988 8804 4002 8846 4039 8846 4019 8794
      3988 8794

$$

Auten

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 3:31 PM CDT	Special Weather Statement	ILX	Vermilion	44 min
Jul 11, 4:04 PM CDT	Severe Thunderstorm Warning	ILX	McLean, Woodford	56 min
Jul 11, 4:11 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, McLean, Piatt	64 min
Jul 11, 4:29 PM CDT	Severe Thunderstorm Warning	ILX	McLean, Woodford	61 min
Jul 11, 4:59 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Piatt	61 min
Jul 11, 5:31 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Douglas, Edgar, Vermilion	59 min
Jul 11, 5:55 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Piatt	65 min
Jul 11, 6:31 PM CDT	Severe Thunderstorm Warning	ILX	Clark, Edgar	29 min

Nearby

Flash Flood Warnings in Illinois, 2020 Every flash flood warning in 2020

Sources

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