Alert archive / Illinois / Flash Flood Warnings in 2021

Flash Flood Warning 20, NWS Lincoln, IL

July 15, 2021DeWitt County, McLean County, Illinois

NWS Lincoln, IL issued this flash flood warning at Jul 15, 2021, 5:01 PM CDT for DeWitt County, McLean 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 15, 2021, 5:01 PM CDT (22:01 UTC)
Expired: Jul 15, 2021, 7:50 PM CDT
In force: 3 hr
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Flood severity: None

Counties DeWitt County, IL, McLean County, IL

The radar

The Lincoln radar (KILX), 42 km from the middle of the area, began a volume at 22:01 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, 10.0 hours before the alert went out and 32 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: 628 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 1096 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 217 m²/s²
0-3 km storm-relative helicity: 188 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.6

Open this sounding in Storm Lab

The text

As transmitted.

397 
WGUS53 KILX 152201
FFWILX
ILC039-113-160100-
/O.NEW.KILX.FF.W.0020.210715T2201Z-210716T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
501 PM CDT Thu Jul 15 2021

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  North Central De Witt County in central Illinois...
  Southeastern McLean County in central Illinois...

* Until 800 PM CDT.

* At 501 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  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, 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 4028 8905 4029 8906 4052 8875 4039 8857
      4020 8890

FLASH FLOOD...RADAR INDICATED

$$

Barnes

1 follow-up statement

622 
WGUS73 KILX 160050
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
750 PM CDT Thu Jul 15 2021

ILC039-113-160100-
/O.CAN.KILX.FF.W.0020.000000T0000Z-210716T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
De Witt IL-McLean IL-
750 PM CDT Thu Jul 15 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTH CENTRAL DE WITT AND 
SOUTHEASTERN MCLEAN COUNTIES...

Flood waters have receded, but the ditches remain full. Flooding is 
no longer expected to pose a threat. Please continue to heed 
remaining road closures.

LAT...LON 4028 8905 4029 8906 4052 8875 4039 8857
      4020 8890

$$

Shimon

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 4:52 AM CDT	Flash Flood Warning	ILX	Marshall, Peoria, Stark, Woodford	5 hr
Jul 15, 12:48 PM CDT	Special Weather Statement	ILX	Christian, Clark, Coles, Cumberland, Douglas, Edgar and 6 more	117 min
Jul 15, 1:40 PM CDT	Tornado Warning	ILX	Coles	34 min
Jul 15, 3:39 PM CDT	Severe Thunderstorm Warning	ILX	Logan, Mason, Menard, Sangamon	66 min
Jul 15, 4:19 PM CDT	Special Weather Statement	ILX	DeWitt	41 min
Jul 15, 4:43 PM CDT	Areal Flood Advisory	ILX	McLean	3 hr
Jul 15, 4:52 PM CDT	Severe Thunderstorm Warning	ILX	DeWitt, McLean, Macon, Piatt	38 min
Jul 15, 5:26 PM CDT	Special Weather Statement	ILX	Champaign	64 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.