Alert archive / Illinois / Flash Flood Warnings in 2022

Flash Flood Warning 7, NWS Chicago, IL

July 5, 20225 counties in Illinois

NWS Chicago, IL issued this flash flood warning at Jul 5, 2022, 9:59 PM CDT for 5 counties in Illinois. It was in force for 5 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: Jul 5, 2022, 9:59 PM CDT (02:59 UTC)
Expired: Jul 6, 2022, 3:00 AM CDT
In force: 5 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

Counties Boone County, IL, DeKalb County, IL, Kane County, IL, McHenry County, IL, Winnebago County, IL

The radar

The Chicago radar (KLOT), 82 km from the middle of the area, began a volume at 03:03 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.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.0 hours before the alert went out and 159 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: 2613 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 1615 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 129 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.1

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 Jul 5, 6:15 PM CDT, 3 hours 44 minutes earlier.

Area forecast discussion, Jul 5, 6:15 PM CDT, 3 hours 44 minutes before

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Hazardous weather outlook, Jul 5, 3:03 PM CDT, 6 hours 56 minutes before

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In the hours before

Special weather statement, Jul 5, 5:29 PM CDT, 4 hours 30 minutes before

Special Weather Statement
National Weather Service Chicago/Romeoville
529 PM CDT Tue Jul 5 2022

ILZ005-052315-
McHenry IL-
529 PM CDT Tue Jul 5 2022

...A strong thunderstorm will impact portions of McHenry County
through 615 PM CDT...

At 528 PM CDT, Doppler radar was tracking a cluster of strong
thunderstorms over northern McHenry County, moving southeast at 10
mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
McHenry, Woodstock, Fox Lake, Harvard, Island Lake, Johnsburg,
Lakemoor, Twin Lakes, Spring Grove, Wonder Lake, Pistakee Highlands,
Genoa City, Prairie Grove, Richmond, Hebron, Bull Valley, McCullom
Lake, Ringwood, Holiday Hills and Chemung.

This includes...Mchenry County Fairgrounds and Moraine Hills State
Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until midnight CDT for
north central and northeastern Illinois.

&&

LAT...LON 4227 8820 4230 8871 4249 8871 4250 8820
TIME...MOT...LOC 2228Z 299DEG 8KT 4243 8851

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Kluber

Local storm report, Jul 5, 6:49 PM CDT, 3 hours 10 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
Jul 5, 7:08 PM CDT	Areal Flood Advisory	LOT	Boone, McHenry	5 hr
Jul 5, 7:14 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Kane, McHenry	76 min
Jul 5, 8:06 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Kane	34 min
Jul 5, 8:40 PM CDT	Areal Flood Advisory	LOT	DeKalb, Kane	4 hr
Jul 5, 8:50 PM CDT	Areal Flood Advisory	LOT	Winnebago	4 hr
Jul 5, 9:02 PM CDT	Special Weather Statement	LOT	DeKalb	28 min
Jul 5, 9:31 PM CDT	Special Weather Statement	LOT	Kane	44 min
Jul 6, 2:53 AM CDT	Special Weather Statement	LOT	Newton	37 min
Jul 6, 3:24 AM CDT	Special Weather Statement	LOT	Benton	21 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.