Alert archive / Illinois / Flash Flood Warnings in 2021

Flash Flood Warning 15, NWS Lincoln, IL

July 11, 2021Logan County, Illinois

NWS Lincoln, IL issued this flash flood warning at Jul 11, 2021, 6:00 PM CDT for Logan County, Illinois. It was in force for 5 hr. 2 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
Jul 11, 2021, 6:00 PM CDT (23:00 UTC)
Expired
Jul 11, 2021, 11:00 PM CDT
In force
5 hr
Issued by
NWS Lincoln, IL
Area
Storm-based polygon
Flood severity
None

County Logan County, IL

The radar

The Lincoln radar (KILX), 7 km from the middle of the area, began a volume at 23:03 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
Jul 11, 6:38 PM CDTFLASH FLOODMount Pulaski, ILESTIMATED WATER NEAR 1 FOOT DEEP ON SEVERAL ROADS IN TOWN.
Jul 11, 7:00 PM CDTHEAVY RAIN 3.77Mount Pulaski, ILRAINFALL SINCE 530 PM.

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, 11.0 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 2021-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 307 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 2021-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.1939587897Sfc1 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
307 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
520 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

460 
WGUS53 KILX 112300
FFWILX
ILC107-120200-
/O.NEW.KILX.FF.W.0015.210711T2300Z-210712T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
600 PM CDT Sun Jul 11 2021

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  Southeastern Logan County in central Illinois...

* Until 900 PM CDT.

* At 559 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 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...
  Lincoln and Mount Pulaski.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4020 8938 4020 8925 3992 8925 3992 8939

FLASH FLOOD...RADAR INDICATED

$$

MJA
3 follow-up statements
679 
WGUS73 KILX 120059
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
759 PM CDT Sun Jul 11 2021

ILC107-120200-
/O.CON.KILX.FF.W.0015.000000T0000Z-210712T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Logan IL-
759 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM CDT THIS EVENING 
FOR SOUTH CENTRAL LOGAN COUNTY...

At 756 PM CDT, local law enforcement reported urban flooding in 
Mount Pulaski. Between 3 and 5 inches of rain have fallen over much 
of the warned area. Flash flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement.

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...
  Lincoln and Mount Pulaski.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4020 8938 4011 8925 3992 8925 3992 8939

FLASH FLOOD...OBSERVED

$$

37
124 
WGUS53 KILX 120150
FFWILX
ILC107-120400-
/O.EXT.KILX.FF.W.0015.000000T0000Z-210712T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
850 PM CDT Sun Jul 11 2021

The National Weather Service in Lincoln has extended the

* Flash Flood Warning for...
  South Central Logan County in central Illinois...

* Until 1100 PM CDT.

* At 849 PM CDT, local law enforcement reported areas of flooding on 
  State Route 121 near Mount Pulaski as well as urban flooding in 
  Mount Pulaski. Between 2.5 and 4.5 inches of rain have fallen. 
  Flash flooding is already occurring.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Law enforcement.

  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...
  Lincoln and Mount Pulaski.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4020 8938 4011 8925 3992 8925 3992 8939

FLASH FLOOD...OBSERVED

$$

37
862 
WGUS73 KILX 120353
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
1053 PM CDT Sun Jul 11 2021

ILC107-120403-
/O.EXP.KILX.FF.W.0015.000000T0000Z-210712T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Logan IL-
1053 PM CDT Sun Jul 11 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 11 PM CDT THIS EVENING FOR 
SOUTH CENTRAL LOGAN COUNTY...

The heavy rain has ended. Flash flooding is no longer expected to 
pose a threat. Please continue to heed remaining road closures.

LAT...LON 4020 8938 4011 8925 3992 8925 3992 8939

$$

37

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 3:31 PM CDTFlash Flood WarningILXSchuyler3 hr
Jul 11, 5:07 PM CDTFlash Flood WarningILXLogan, Mason, Menard6 hr

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.