Alert archive / Illinois / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 57, NWS Chicago, IL

July 17, 2016Ogle County, Winnebago County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 17, 2016, 6:45 AM CDT for Ogle County, Winnebago County, Illinois. It was in force for 45 min. 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 17, 2016, 6:45 AM CDT (11:45 UTC)
Expired: Jul 17, 2016, 7:30 AM CDT
In force: 45 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Ogle County, IL, Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 103 km from the middle of the area, began a volume at 11:49 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, 11.8 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.

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: 1263 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 71 m²/s²
0-3 km storm-relative helicity: 182 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 severe thunderstorm 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 severe thunderstorm warning went out at Jul 17, 3:34 AM CDT, 3 hours 11 minutes earlier.

Area forecast discussion, Jul 17, 3:34 AM CDT, 3 hours 11 minutes before

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Hazardous weather outlook, Jul 17, 4:32 AM CDT, 2 hours 13 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 17, 3:03 AM CDT	Small Craft Advisory	LOT		18 hr
Jul 17, 7:15 AM CDT	Special Weather Statement	LOT	Lee	30 min
Jul 17, 7:45 AM CDT	Special Weather Statement	LOT	DeKalb, Kane, Kendall, LaSalle	45 min
Jul 17, 9:53 AM CDT	Special Marine Warning	LOT		97 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2016 Every severe thunderstorm warning in 2016

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.