Alert archive / Illinois / Flash Flood Warnings in 2021
Flash Flood Warning 4, NWS Chicago, IL
NWS Chicago, IL issued this flash flood warning at Jul 12, 2021, 8:42 PM CDT for Grundy County, LaSalle County, Illinois. It was in force for 5 hr. 9 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 12, 2021, 8:42 PM CDT (01:42 UTC)
- Expired
- Jul 13, 2021, 1:30 AM CDT
- In force
- 5 hr
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Flood severity
- None
Counties Grundy County, IL, LaSalle County, IL
The radar
The Chicago radar (KLOT), 60 km from the middle of the area, began a volume at 01:43 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 |
|---|---|---|---|
| Jul 12, 9:55 PM CDT | FLASH FLOOD | 3 N Kinsman, IL | OVER ONE FOOT OF WATER FLOWING OVER THE ROADWAY AT THE INTERSECTION OF S KINSMAN AND W GRAND RIDGE ROADS. |
| Jul 12, 10:19 PM CDT | HEAVY RAIN 6.19 | 4 Nw Verona, IL | 3 HOUR RAINFALL TOTAL OF 6.19 INCHES FROM A PERSONAL WEATHER STATION. |
| Jul 12, 10:30 PM CDT | FLASH FLOOD | 3 Nw Kinsman, IL | WATER OF A FOOT OVER ILLINOIS HIGHWAY 170. THIS WAS CONTINUING AT 1 A.M. ON JULY 13 BUT LIKELY BEGAN MUCH EARLIER. TIME ESTIMATED BY RADAR. |
| Jul 12, 10:34 PM CDT | HEAVY RAIN 4.24 | 1 E Seneca, IL | 3-HOUR RAINFALL TOTAL OF 4.24 INCHES FROM A PERSONAL WEATHER STATION IN SENECA. |
| Jul 12, 10:38 PM CDT | FLASH FLOOD | 1 Ese Seneca, IL | WATER RESCUES PERFORMED AT THE INTERSECTION OF DUPONT AND KINSMAN RD. AT LEAST 3 VEHICLES STUCK IN THE FLOODED ROADWAY. |
| Jul 12, 10:39 PM CDT | HEAVY RAIN 4.58 | 3 E Seneca, IL | 4-HOUR RAINFALL TOTAL OF 4.58 INCHES FROM A PERSONAL WEATHER STATION. |
| Jul 12, 10:56 PM CDT | FLASH FLOOD | 1 S Seneca, IL | BRIDGE PARTIALLY WASHED OUT ON RIVER ROAD JUST WEST OF IL 170. RELAYED VIA SOCIAL MEDIA. |
| Jul 12, 11:50 PM CDT | FLASH FLOOD | 2 Ese Seneca, IL | SEVERAL INCHES OF WATER RUSHING OVER KINSMAN ROAD DUE TO RISING WATER IN ARMSTRONG RUN. |
| Jul 13, 1:15 AM CDT | FLASH FLOOD | 2 Se Seneca, IL | PART OF INDIANA TRAIL ROAD WASHED OUT WITH WATER CONTINUING OVER THE ROAD. |
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 00:00Z, 1.7 hours before the alert went out and 122 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.
- Mixed-layer CAPE
- 235 J/kg
- Mixed-layer CIN
- -19 J/kg
- Mixed-layer LCL
- 949 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 37 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
672
WGUS53 KLOT 130142
FFWLOT
ILC063-099-130630-
/O.NEW.KLOT.FF.W.0004.210713T0142Z-210713T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Chicago IL
842 PM CDT Mon Jul 12 2021
The National Weather Service in Chicago has issued a
* Flash Flood Warning for...
East Central La Salle County in north central Illinois...
Southwestern Grundy County in northeastern Illinois...
* Until 130 AM CDT.
* At 842 PM CDT, doppler radar indicated nearly stationary showers
producing heavy rain across the warned area. Between 1.5 and 3
inches of rain have fallen. Additional rainfall amounts of 1 to 3
inches are probable across the warned area. Flash flooding is
expected to begin shortly.
HAZARD...Flash flooding.
SOURCE...Radar.
IMPACT...Rapid-onset flooding of small creeks and streams,
highways, streets and underpasses, as well as other
poor drainage and low lying areas.
* Some locations that will experience flash flooding include...
Seneca, Ransom, Kinsman, U.S. Highway 6 near Seneca, Illinois
Routes 17 and 170, as well as Hog Run and Waupecan Creek.
This also includes the Marseilles State Fish and Wildlife Area and
the LaSalle Lake State Fish and Wildlife Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Expect flooding of creeks, ditches, farmland, roadways, and and
other low lying areas.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4135 8865 4135 8854 4121 8854 4111 8858
4111 8871 4128 8871
FLASH FLOOD...RADAR INDICATED
$$
Friedlein4 follow-up statements
173
WGUS73 KLOT 130307
FFSLOT
Flash Flood Statement
National Weather Service Chicago IL
1007 PM CDT Mon Jul 12 2021
ILC063-099-130630-
/O.CON.KLOT.FF.W.0004.000000T0000Z-210713T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grundy IL-La Salle IL-
1007 PM CDT Mon Jul 12 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 AM CDT TUESDAY
FOR EAST CENTRAL LA SALLE AND SOUTHWESTERN GRUNDY COUNTIES...
At 1007 PM CDT, doppler radar indicated nearly stationary heavy
showers and thunderstorms along and near the border of LaSalle and
Grundy Counties. Trained weather spotters and law enforcement
reported flash flooding in the area, including in and near the town
of Seneca. Between 2 and 5 inches of rain have fallen. Additional
rainfall amounts of 1 to 3 inches are possible in the warned area.
Flash flooding is already occurring.
HAZARD...Significant flash flooding.
SOURCE...Trained spotters 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...Seneca,
Ransom, Kinsman, rural Verona area, U.S. Highway 6 near Seneca,
Illinois Routes 170 and 17, as well as Hog Run, Waupecan Creek, and
North and South Kickapoo Creeks.
This also includes the Marseilles State Fish and Wildlife Area and
the LaSalle Lake State Fish and Wildlife Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Flash Flood Warning means rapid-onset flooding is imminent or may
already be occurring. Persons along creeks, drainage ditches, and
other waterways should take immediate precautions to protect life
and property.
Expect flooding of creeks, ditches, farmland, roadways, and and
other low lying areas.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4135 8865 4135 8854 4121 8854 4111 8858
4111 8871 4128 8871
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Friedlein441
WGUS73 KLOT 130420
FFSLOT
Flash Flood Statement
National Weather Service Chicago IL
1120 PM CDT Mon Jul 12 2021
ILC063-099-130630-
/O.CON.KLOT.FF.W.0004.000000T0000Z-210713T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grundy IL-La Salle IL-
1120 PM CDT Mon Jul 12 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 AM CDT TUESDAY
FOR EAST CENTRAL LA SALLE AND SOUTHWESTERN GRUNDY COUNTIES...
At 1120 PM CDT, local law enforcement and trained spotters reported
significant flash flooding along and near the border of LaSalle and
Grundy Counties, including the town of Seneca. There have been
reports of vehicles stalled in water. Between 2 and 6.5 inches of
rain have fallen in the warning area. Scattered showers, some with
heavy downpours, will be seen through the overnight. Water will be
slow to subside and conditions will remain dangerous.
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...Seneca,
Ransom, Kinsman, rural Verona area, U.S. Highway 6 near Seneca,
Illinois Routes 170 and 17, as well as Hog Run, Waupecan Creek, and
North and South Kickapoo Creeks.
This also includes the Marseilles State Fish and Wildlife Area and
the LaSalle Lake State Fish and Wildlife Area.
There is considerable flooding occurring in and near Seneca. Travel
is strongly discouraged in this area into the overnight.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Flash Flood Warning means rapid-onset flooding is imminent or may
already be occurring. Persons along creeks, drainage ditches, and
other waterways should take immediate precautions to protect life
and property.
Expect flooding of creeks, ditches, farmland, roadways, and and
other low lying areas.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4135 8865 4135 8854 4121 8854 4111 8858
4111 8871 4128 8871
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Friedlein714
WGUS73 KLOT 130536
FFSLOT
Flash Flood Statement
National Weather Service Chicago IL
1236 AM CDT Tue Jul 13 2021
ILC063-099-130630-
/O.CON.KLOT.FF.W.0004.000000T0000Z-210713T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grundy IL-La Salle IL-
1236 AM CDT Tue Jul 13 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 AM CDT EARLY THIS
MORNING FOR EAST CENTRAL LA SALLE AND SOUTHWESTERN GRUNDY COUNTIES...
At 1236 AM CDT, local law enforcement continued to report
significant flash flooding along and near the border of LaSalle and
Grundy Counties, including the town of Seneca. There have been
reports of vehicles stalled in water in this area. Between 2 and 6.5
inches of rain fell in the warned area Monday evening. Scattered
showers, some with heavy downpours, will be seen through the
overnight. Water will be slow to subside and conditions will remain
dangerous. An areal Flood Warning through daybreak will likely
replace the Flash Flood Warning after its expiration.
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...
Seneca,
Ransom, Kinsman, rural Verona area, U.S. Highway 6 near Seneca,
Illinois Routes 170 and 17, as well as Hog Run, Waupecan Creek, and
North and South Kickapoo Creeks.
This also includes the Marseilles State Fish and Wildlife Area and
the LaSalle Lake State Fish and Wildlife Area.
There is considerable flooding occurring in and near Seneca. Travel
is strongly discouraged in this area into the overnight.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Flash Flood Warning means rapid-onset flooding is imminent or may
already be occurring. Persons along creeks, drainage ditches, and
other waterways should take immediate precautions to protect life
and property.
Expect flooding of creeks, ditches, farmland, roadways, and and
other low lying areas.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4135 8865 4135 8854 4121 8854 4111 8858
4111 8871 4128 8871
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Friedlein401
WGUS73 KLOT 130632
FFSLOT
Flash Flood Statement
National Weather Service Chicago IL
132 AM CDT Tue Jul 13 2021
ILC063-099-130642-
/O.EXP.KLOT.FF.W.0004.000000T0000Z-210713T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grundy IL-La Salle IL-
132 AM CDT Tue Jul 13 2021
...FLASH FLOOD WARNING HAS EXPIRED FOR EAST CENTRAL LA SALLE AND
SOUTHWESTERN GRUNDY COUNTIES...
Much of this warning has been replaced by an Areal Flood Warning
through 1030 AM CDT this morning as numerous flooded roads continue.
Please continue to heed road closures.
LAT...LON 4135 8865 4135 8854 4121 8854 4111 8858
4111 8871 4128 8871
$$
FriedleinThe office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 12, 8:14 PM CDT | Areal Flood Advisory | LOT | Grundy, LaSalle, Livingston | 4 hr |
| Jul 12, 10:33 PM CDT | Areal Flood Advisory | LOT | Grundy | 4 hr |
| Jul 12, 11:56 PM CDT | Flash Flood Warning | LOT | Grundy, Livingston, Will | 4 hr |
| Jul 13, 1:29 AM CDT | Areal Flood Warning | LOT | Grundy, LaSalle | 9 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.