Alert archive / Illinois / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 196, NWS Lincoln, IL

July 20, 2023Morgan County, Sangamon County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Jul 20, 2023, 8:52 AM CDT for Morgan County, Sangamon County, Illinois. It was in force for 38 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 20, 2023, 8:52 AM CDT (13:52 UTC)
Expired: Jul 20, 2023, 9:30 AM CDT
In force: 38 min
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Morgan County, IL, Sangamon County, IL

The radar

The Lincoln radar (KILX), 68 km from the middle of the area, began a volume at 13:55 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

Lincoln, IL (KILX), launched 12:00Z, 1.9 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: 1586 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 680 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 66 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.2

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 Lincoln, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 20, 5:55 AM CDT, 2 hours 57 minutes earlier.

Area forecast discussion, Jul 20, 5:55 AM CDT, 2 hours 57 minutes before

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Hazardous weather outlook, Jul 20, 5:32 AM CDT, 3 hours 20 minutes before

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In the hours before

Special weather statement, Jul 20, 7:54 AM CDT, 58 minutes before

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Special weather statement, Jul 20, 8:34 AM CDT, 18 minutes before

Special Weather Statement
National Weather Service Lincoln IL
834 AM CDT Thu Jul 20 2023

ILZ050-201400-
Morgan-
834 AM CDT Thu Jul 20 2023

...A strong thunderstorm will impact portions of northeastern Morgan
County through 900 AM CDT...

At 833 AM CDT, Doppler radar was tracking a strong thunderstorm near
Jacksonville, moving east at 20 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This strong thunderstorm will be near...
  Alexander around 850 AM CDT.

This includes Interstate 72 between mile markers 66 and 78.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3968 9021 3980 9025 3987 9001 3969 8999
TIME...MOT...LOC 1333Z 257DEG 16KT 3976 9015

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Deubelbeiss/Delaney

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 7:54 AM CDT	Special Weather Statement	ILX	Scott	36 min
Jul 20, 8:01 AM CDT	Severe Thunderstorm Warning	ILX	Morgan, Scott	44 min
Jul 20, 8:34 AM CDT	Special Weather Statement	ILX	Morgan	26 min
Jul 20, 1:55 PM CDT	Severe Thunderstorm Warning	ILX	Coles, Cumberland, Shelby	18 min
Jul 20, 2:05 PM CDT	Severe Thunderstorm Warning	ILX	Edgar, Vermilion	25 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2023 Every severe thunderstorm 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.