Alert archive / Illinois / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 48, NWS Chicago, IL

August 1, 2018DuPage County, Kane County, Will County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Aug 1, 2018, 5:17 PM CDT for DuPage County, Kane County, Will County, Illinois. It was in force for 18 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
Aug 1, 2018, 5:17 PM CDT (22:17 UTC)
Expired
Aug 1, 2018, 5:35 PM CDT
In force
18 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties DuPage County, IL, Kane County, IL, Will County, IL

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.3 hours before the alert went out and 194 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 2018-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 175 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2018-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
175 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
1347 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
65 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 Aug 1, 2:34 PM CDT, 2 hours 43 minutes earlier.

Area forecast discussion, Aug 1, 2:34 PM CDT, 2 hours 43 minutes before
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Hazardous weather outlook, Aug 1, 3:28 PM CDT, 1 hour 49 minutes before
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In the hours before

Local storm report, Aug 1, 3:25 PM CDT, 1 hour 52 minutes before
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Special weather statement, Aug 1, 4:30 PM CDT, 47 minutes before
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Special weather statement, Aug 1, 5:11 PM CDT, 6 minutes before
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Local storm report, Aug 1, 5:11 PM CDT, 6 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
511 PM CDT WED AUG 1 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     HAIL             3 NNW AURORA            41.81N 88.33W
08/01/2018  E0.75 INCH       KANE               IL   TRAINED SPOTTER

            DIME SIZE HAIL NEAR ROUTES 31 AND 56.

&&

BMD
Local storm report, Aug 1, 5:15 PM CDT, 2 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
515 PM CDT WED AUG 1 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0510 PM     HAIL             5 NNW AURORA            41.83N 88.32W
08/01/2018  E1.00 INCH       KANE               IL   CO-OP OBSERVER

&&

BMD
Local storm report, Aug 1, 5:17 PM CDT, 0 minutes before
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      <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.

IssuedProductOfficeCountiesLasted
Aug 1, 2:56 PM CDTSpecial Weather StatementLOTDuPage19 min
Aug 1, 3:14 PM CDTSpecial Weather StatementLOTDuPage16 min
Aug 1, 3:20 PM CDTSpecial Marine WarningLOT25 min
Aug 1, 3:51 PM CDTSpecial Marine WarningLOT39 min
Aug 1, 4:41 PM CDTSpecial Marine WarningLOT49 min
Aug 1, 5:11 PM CDTSpecial Weather StatementLOTDuPage19 min
Aug 1, 5:31 PM CDTSpecial Marine WarningLOT29 min
Aug 1, 6:54 PM CDTSpecial Weather StatementLOTKane21 min
Aug 1, 4:30 PM CDTSpecial Weather StatementLOTLake30 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2018Every severe thunderstorm warning in 2018

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.