Alert archive / Illinois / Flash Flood Warnings in 2021

Flash Flood Warning 25, NWS Lincoln, IL

August 8, 2021McLean County, Illinois

NWS Lincoln, IL issued this flash flood warning at Aug 8, 2021, 5:35 PM CDT for McLean County, Illinois. It was in force for 3 hr. 5 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
Aug 8, 2021, 5:35 PM CDT (22:35 UTC)
Expired
Aug 8, 2021, 8:45 PM CDT
In force
3 hr
Issued by
NWS Lincoln, IL
Area
Storm-based polygon
Flood severity
None

County McLean County, IL

The radar

The Lincoln radar (KILX), 46 km from the middle of the area, began a volume at 22:35 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

TimeReportWhereRemark
Aug 8, 5:50 PM CDTFLASH FLOOD2 Nne Danvers, ILCARLOCK DANVERS BLACKTOP UNDER WATER FROM HEAVY RAINS.
Aug 8, 6:35 PM CDTFLASH FLOODDanvers, ILFLOODED ROADS IN DANVERS AREA.
Aug 8, 7:00 PM CDTFLASH FLOODCarlock, ILSOME FLOODED VEHICLES ALONG HIGHWAY 150 BETWEEN CARLOCK AND BLOOMINGTON.
Aug 8, 8:30 PM CDTHEAVY RAIN 8.25Danvers, ILFLOODED VEHICLES ON S. WEST STREET.
Aug 8, 8:45 PM CDTHEAVY RAIN 5.09Carlock, ILRAINFALL PAST 4 HOURS. SOME UNUSUAL FLOODING IN CARLOCK.

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, 10.6 hours before the alert went out and 62 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 310 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
310 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1165 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

484 
WGUS53 KILX 082235
FFWILX
ILC113-090145-
/O.NEW.KILX.FF.W.0025.210808T2235Z-210809T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
535 PM CDT Sun Aug 8 2021

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  West Central McLean County in central Illinois...

* Until 845 PM CDT.

* At 535 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Additional rainfall amounts up to 1 inch are possible 
  in the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Normal, Hudson, Danvers and Carlock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4044 8926 4054 8926 4065 8896 4058 8892

FLASH FLOOD...RADAR INDICATED

$$

37
2 follow-up statements
864 
WGUS73 KILX 082303
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
603 PM CDT Sun Aug 8 2021

ILC113-090145-
/O.CON.KILX.FF.W.0025.000000T0000Z-210809T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
McLean IL-
603 PM CDT Sun Aug 8 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM CDT THIS 
EVENING FOR WEST CENTRAL MCLEAN COUNTY...

At 600 PM CDT, emergency management reported flooding between 
Danvers and Carlock, with water over the Carlock Danvers Blacktop 
submerged. Between 2 and 4 inches of rain have fallen. Additional 
rainfall amounts up to 2 inches are possible in the warned area. 
Flash flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Emergency management reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Normal, Hudson, Danvers and Carlock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4044 8926 4054 8926 4065 8896 4058 8892

FLASH FLOOD...OBSERVED

$$

37
089 
WGUS73 KILX 090140
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
840 PM CDT Sun Aug 8 2021

ILC113-090150-
/O.EXP.KILX.FF.W.0025.000000T0000Z-210809T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
McLean IL-
840 PM CDT Sun Aug 8 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 845 PM CDT THIS EVENING FOR 
WEST CENTRAL MCLEAN COUNTY...

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

LAT...LON 4044 8926 4054 8926 4065 8896 4058 8892

$$

Auten

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 2:21 PM CDTSpecial Weather StatementILXMcLean24 min
Aug 8, 3:30 PM CDTSpecial Weather StatementILXMcLean30 min
Aug 8, 4:29 PM CDTSpecial Weather StatementILXMorgan31 min
Aug 8, 4:45 PM CDTAreal Flood AdvisoryILXMcLean2 hr
Aug 8, 4:54 PM CDTSpecial Weather StatementILXMenard36 min
Aug 8, 5:02 PM CDTSpecial Weather StatementILXWoodford28 min
Aug 8, 5:05 PM CDTSevere Thunderstorm WarningILXLogan, Mason, Menard25 min
Aug 8, 5:14 PM CDTSevere Thunderstorm WarningILXMcLean, Tazewell, Woodford46 min
Aug 8, 5:29 PM CDTSpecial Weather StatementILXSangamon31 min
Aug 8, 5:46 PM CDTSpecial Weather StatementILXSangamon29 min

Nearby

Flash Flood Warnings in Illinois, 2021Every 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.