Alert archive / Illinois / Flash Flood Warnings in 2022

Flash Flood Warning 18, NWS Chicago, IL

August 19, 2022Ogle County, Illinois

NWS Chicago, IL issued this flash flood warning at Aug 19, 2022, 9:21 PM CDT for Ogle 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 counties it named.

The facts

Issued: Aug 19, 2022, 9:21 PM CDT (02:21 UTC)
Expired: Aug 20, 2022, 12:30 AM CDT
In force: 3 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

County Ogle County, IL

The radar

The Chicago radar (KLOT), 113 km from the middle of the area, began a volume at 02:23 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

Davenport, (KDVN), launched 00:00Z, 2.4 hours before the alert went out and 108 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: 1987 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 1111 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before this flash flood warning went out at Aug 19, 9:00 PM CDT, 21 minutes earlier.

Area forecast discussion, Aug 19, 9:00 PM CDT, 21 minutes before

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Hazardous weather outlook, Aug 19, 9:10 PM CDT, 11 minutes before

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In the hours before

Special weather statement, Aug 19, 7:29 PM CDT, 1 hour 52 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 19, 7:29 PM CDT	Special Weather Statement	LOT	Ogle	46 min
Aug 19, 9:05 PM CDT	Areal Flood Advisory	LOT	Ogle	3 hr
Aug 19, 11:15 PM CDT	Areal Flood Advisory	LOT	Ogle, Winnebago	3 hr
Aug 20, 12:29 AM CDT	Areal Flood Advisory	LOT	Ogle	5 hr
Aug 20, 2:38 PM CDT	Special Weather Statement	LOT	LaSalle	37 min
Aug 20, 3:21 PM CDT	Special Weather Statement	LOT	Grundy	39 min
Aug 20, 3:26 PM CDT	Severe Thunderstorm Warning	LOT	Grundy, LaSalle	49 min
Aug 20, 4:11 PM CDT	Special Weather Statement	LOT	Grundy	49 min

Nearby

Flash Flood Warnings in Illinois, 2022 Every flash flood warning in 2022

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.