Alert archive / Illinois / Red Flag Warnings in 2007

Red Flag Warning 1, NWS Chicago, IL

May 23, 200718 counties in Illinois; 5 counties in Indiana

NWS Chicago, IL issued this red flag warning at May 23, 2007, 12:38 PM CDT for 18 counties in Illinois; 5 counties in Indiana. It took effect at May 23, 2007, 1:00 PM CDT. It was in force for 7 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: May 23, 2007, 12:38 PM CDT (17:38 UTC)
In effect from: May 23, 2007, 1:00 PM CDT
Expired: May 23, 2007, 8:00 PM CDT
In force: 7 hr
Issued by: NWS Chicago, IL

All 23 counties

Boone County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, McHenry County, IL, Ogle County, IL, Will County, IL, Winnebago County, IL, Benton County, IN, Jasper County, IN, Lake County, IN, Newton County, IN, Porter County, IN

The radar

The Chicago radar (KLOT), 12 km from the middle of the area, began a volume at 17:38 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 12:00Z, 5.6 hours before the alert went out and 193 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1677 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 225 m²/s²
0-3 km storm-relative helicity: 213 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this red flag 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 red flag warning went out at May 23, 6:10 AM CDT, 6 hours 28 minutes earlier.

Area forecast discussion, May 23, 6:10 AM CDT, 6 hours 28 minutes before

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Hazardous weather outlook, May 23, 4:30 AM CDT, 8 hours 8 minutes before

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Nearby

Red Flag Warnings in Illinois, 2007 Red Flag Warnings in Indiana, 2007 Every red flag warning in 2007

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.