Alert archive / Illinois / Winter Storm Warnings in 2023

Winter Storm Warning 2, NWS Chicago, IL

February 15, 20235 counties in Illinois

NWS Chicago, IL issued this winter storm warning at Feb 15, 2023, 2:13 PM CST for 5 counties in Illinois. It took effect at Feb 16, 2023, 3:00 AM CST. It was in force for 21 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: Feb 15, 2023, 2:13 PM CST (20:13 UTC)
In effect from: Feb 16, 2023, 3:00 AM CST
Expired: Feb 17, 2023, 12:00 AM CST
In force: 21 hr
Issued by: NWS Chicago, IL

Counties Boone County, IL, Lake County, IL, McHenry County, IL, Ogle County, IL, Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 78 km from the middle of the area, began a volume at 20:15 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 8.2 hours before the alert went out and 250 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: 746 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 199 m²/s²
0-3 km storm-relative helicity: 263 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 winter storm 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 winter storm warning went out at Feb 14, 3:31 PM CST, 22 hours 42 minutes earlier.

Area forecast discussion, Feb 14, 3:31 PM CST, 22 hours 42 minutes before

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Hazardous weather outlook, Feb 14, 4:17 PM CST, 21 hours 56 minutes before

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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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        Please try again in a few minutes.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 15, 3:35 AM CST	Winter Weather Advisory	LOT	Cook, DeKalb, DuPage, Grundy, Kane, Kendall and 3 more	53 hr
Feb 15, 3:38 AM CST	Gale Watch	LOT		15 hr
Feb 15, 3:03 PM CST	Small Craft Advisory	LOT		3 hr

Nearby

Winter Storm Warnings in Illinois, 2023 Every winter storm warning in 2023

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.