Alert archive / Illinois / Flash Flood Warnings in 2021

Flash Flood Warning 6, NWS Chicago, IL

August 12, 2021Ford County, Illinois

NWS Chicago, IL issued this flash flood warning at Aug 12, 2021, 9:59 AM CDT for Ford County, Illinois. It was in force for 5 hr. 6 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 12, 2021, 9:59 AM CDT (14:59 UTC)
Expired: Aug 12, 2021, 3:00 PM CDT
In force: 5 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

County Ford County, IL

The radar

The Lincoln radar (KILX), 95 km from the middle of the area, began a volume at 15:02 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
Aug 12, 10:44 AM CDT	FLASH FLOOD	Gibson City, IL	PARTS OF ROUTE 9 AND ROUTE 47 HAVE A FOOT OF WATER ON THEM IN AND AROUND GIBSON CITY. MULTIPLE CARS STALLED IN WATER.
Aug 12, 11:58 AM CDT	FLASH FLOOD	1 S Gibson City, IL	NUMEROUS CITY ROADS WITH 2-3 FEET OF WATER IN GIBSON CITY, WITH HOMES BEGINNING TO TAKE ON WATER IN PARTS OF TOWN. MULTIPLE ROADS ARE CLOSED.
Aug 12, 12:51 PM CDT	FLASH FLOOD	1 S Gibson City, IL	SIGNIFICANT FLASH FLOODING OCCURRING IN AND AROUND GIBSON CITY, AND POINTS SOUTH AND WEST. WATER IS INUNDATING HOMES AND BUSINESSES, SEWERS ARE BACKING UP, AND ALL ROADS ARE IMPASSABLE. NUMEROUS WATER RESCUES CONTINUE.
Aug 12, 1:30 PM CDT	HEAVY RAIN 6.74	4 Wnw Gibson City, IL	PRIVATE WEATHER STATION REPORTS 6.74 INCHES SINCE MIDNIGHT. 5.89 INCHES OCCURRED WITH MOST RECENT STORMS SINCE 8 AM. LIGHT RAIN ONGOING.
Aug 12, 1:30 PM CDT	HEAVY RAIN 8.76	Gibson City, IL	PRIVATE WEATHER STATION REPORTS 8.76 INCHES OF RAINFALL SINCE MIDNIGHT. 8.1 INCHES OCCURRED WITH MOST RECENT STORMS WHICH BEGAN AT 8:30 AM. MULTIPLE 1 HOUR PERIODS WITH OVER 2 INCHES OF RAINFALL. LIGHT RAIN ONGOING.
Aug 12, 2:14 PM CDT	FLASH FLOOD	1 Se Gibson City, IL	WATER RESCUES CONTINUE AT A SENIOR CITIZENS CENTER THAT WAS INUNDATED WITH WATER. MOST ROADWAYS REMAIN IMPASSABLE.

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, 3.0 hours before the alert went out and 43 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: 1191 J/kg
Mixed-layer CIN: -177 J/kg
Mixed-layer LCL: 1149 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 140 m²/s²
0-3 km storm-relative helicity: 128 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

Open this sounding in Storm Lab

The text

As transmitted.

312 
WGUS53 KLOT 121459
FFWLOT
ILC053-121800-
/O.NEW.KLOT.FF.W.0006.210812T1459Z-210812T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Chicago IL
959 AM CDT Thu Aug 12 2021

The National Weather Service in Chicago has issued a

* Flash Flood Warning for...
  Southwestern Ford County in east central Illinois...

* Until 100 PM CDT.

* At 959 AM CDT, doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 4 inches of rain have fallen. Additional rainfall amounts up 
  to 3 inches are possible in the warned area. Flash flooding is 
  ongoing or expected to begin shortly.

  HAZARD...Flash flooding.

  SOURCE...Radar and automated gauges.

  IMPACT...Rapid-onset 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...
  Paxton, Gibson City and Elliott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4051 8846 4048 8802 4040 8804 4040 8846

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Carlaw

4 follow-up statements

346 
WGUS73 KLOT 121557
FFSLOT

Flash Flood Statement
National Weather Service Chicago IL
1057 AM CDT Thu Aug 12 2021

ILC053-121800-
/O.CON.KLOT.FF.W.0006.000000T0000Z-210812T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ford IL-
1057 AM CDT Thu Aug 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 PM CDT THIS 
AFTERNOON FOR SOUTHWESTERN FORD COUNTY...

At 1057 AM CDT, local law enforcement reported thunderstorms 
producing heavy rain across the warned area which has led to 
multiple instances of stalled cars along parts of Route 9 and 47. 
Between 3 and 5 inches of rain have fallen. Additional rainfall 
amounts of 2 to 3 inches are possible in the warned area which will 
exacerbate flooding conditions in the area this morning.

HAZARD...Significant flash flooding.

SOURCE...Law enforcement reported.

IMPACT...Rapid-onset, significant flooding of creeks, drainage
         ditches, and urban areas. Possible flooding of
         structures. Widespread roadway flooding.

Some locations that will experience flash flooding include...
  Paxton, Gibson City and Elliott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4051 8846 4048 8802 4040 8804 4040 8846

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Carlaw

804 
WGUS53 KLOT 121750
FFWLOT
ILC053-122000-
/O.EXT.KLOT.FF.W.0006.000000T0000Z-210812T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Chicago IL
1250 PM CDT Thu Aug 12 2021

The National Weather Service in Chicago has extended the

* Flash Flood Warning for...
  Southwestern Ford County in east central Illinois...

* Until 300 PM CDT.

* At 1250 PM CDT, emergency management reported significant flash 
  flooding was ongoing across Gibson City and south towards the 
  county line with numerous vehicles stalled in flood waters. 
  Between 4 and 8 inches of rain have fallen. Additional rainfall 
  amounts of 1 to 3 inches are possible in the warned area. The 
  heaviest rainfall is expected to end shortly, but significant 
  flash flooding will continue even after the heaviest rainfall ends.

  HAZARD...Significant flash flooding.

  SOURCE...Emergency management reported.

  IMPACT...Rapid-onset, significant flooding of creeks, drainage
           ditches, and urban areas. Possible flooding of
           structures. Widespread roadway flooding.

* Some locations that will experience flash flooding include...
  Paxton, Gibson City and Elliott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4051 8846 4048 8802 4040 8804 4040 8846

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Carlaw

974 
WGUS73 KLOT 121856
FFSLOT

Flash Flood Statement
National Weather Service Chicago IL
156 PM CDT Thu Aug 12 2021

ILC053-122000-
/O.CON.KLOT.FF.W.0006.000000T0000Z-210812T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ford IL-
156 PM CDT Thu Aug 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 3 PM CDT THIS 
AFTERNOON FOR SOUTHWESTERN FORD COUNTY...

At 156 PM CDT, doppler radar indicated the heaviest rainfall had 
shifted south and east of the Gibson City area, but that additional 
rainfall with rates of a few tenths of an inch per hour would likely 
persist into the afternoon. Radar and automated rain gauges indicate 
that 4 to as much as 8 inches of rain has fallen since 9 AM, with 
continued reports of significant amounts of water over roadways and 
in residences. Emergency management asks that individuals continue 
to avoid the area with many roadways in and around Gibson City 
impassible.

HAZARD...Significant flash flooding.

SOURCE...Emergency management reported.

IMPACT...Rapid-onset, significant flooding of creeks, drainage
         ditches, and urban areas. Ongoing flooding of
         structures. Widespread roadway flooding.

Some locations that will experience flash flooding include...
  Paxton, Gibson City and Elliott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4051 8846 4048 8802 4040 8804 4040 8846

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Carlaw

337 
WGUS73 KLOT 122002
FFSLOT

Flash Flood Statement
National Weather Service Chicago IL
302 PM CDT Thu Aug 12 2021

ILC053-122012-
/O.EXP.KLOT.FF.W.0006.000000T0000Z-210812T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ford IL-
302 PM CDT Thu Aug 12 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTHWESTERN FORD COUNTY AND 
HAS BEEN REPLACED WITH A FLOOD WARNING...

The heaviest rainfall has ended, but light rain will continue 
through the afternoon. Numerous roads remain impassible, and water 
will take a considerable amount of time to recede from roads, homes, 
and businesses. The Flash Flood Warning has been allowed to expire, 
and has been replaced with a Flood Warning.

LAT...LON 4051 8846 4048 8802 4040 8804 4040 8846

$$

Carlaw

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 8:57 PM CDT	Severe Thunderstorm Warning	LOT	DuPage, Kane	48 min
Aug 11, 9:43 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	26 min
Aug 12, 12:45 AM CDT	Special Weather Statement	LOT	Kendall	45 min
Aug 12, 1:31 AM CDT	Special Weather Statement	LOT	Livingston	44 min
Aug 12, 2:13 AM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois, Kankakee, Livingston	47 min
Aug 12, 2:22 AM CDT	Special Weather Statement	LOT	Will	38 min
Aug 12, 2:27 AM CDT	Special Weather Statement	LOT	Will	33 min
Aug 12, 2:30 AM CDT	Severe Thunderstorm Warning	LOT	Kankakee, Will	29 min
Aug 12, 2:46 AM CDT	Special Marine Warning	LOT		89 min
Aug 12, 2:50 AM CDT	Special Weather Statement	LOT	LaSalle	40 min
Aug 12, 2:55 AM CDT	Severe Thunderstorm Warning	LOT	Cook	50 min
Aug 12, 3:02 AM CDT	Severe Thunderstorm Warning	LOT	LaSalle	43 min
Aug 12, 3:16 AM CDT	Special Weather Statement	LOT	Grundy, Kendall, Will	44 min
Aug 12, 3:43 AM CDT	Special Weather Statement	LOT	DuPage, Kane, Kendall, Will	47 min
Aug 12, 3:51 AM CDT	Special Weather Statement	LOT	Ford, Iroquois	39 min
Aug 12, 4:59 AM CDT	Special Weather Statement	LOT	Livingston	31 min
Aug 12, 8:01 AM CDT	Special Weather Statement	LOT	Ford	29 min
Aug 12, 8:22 AM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois	68 min
Aug 12, 9:27 AM CDT	Areal Flood Advisory	LOT	Ford	2 hr
Aug 12, 9:30 AM CDT	Special Weather Statement	LOT	Ford	45 min
Aug 12, 12:01 PM CDT	Areal Flood Advisory	LOT	Ford	4 hr
Aug 12, 12:09 PM CDT	Special Weather Statement	LOT	Livingston	51 min
Aug 12, 1:09 PM CDT	Special Weather Statement	LOT	Iroquois	51 min
Aug 12, 2:44 PM CDT	Small Craft Advisory	LOT		7 hr
Aug 12, 2:59 PM CDT	Areal Flood Warning	LOT	Ford	19 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.