Alert archive / Illinois / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 118, NWS St. Louis, MO

May 7, 2023Brown County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 7, 2023, 7:21 PM CDT for Brown County, Illinois. It was in force for 9 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: May 7, 2023, 7:21 PM CDT (00:21 UTC)
Expired: May 7, 2023, 7:30 PM CDT
In force: 9 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Brown County, IL

The radar

The Lincoln radar (KILX), 122 km from the middle of the area, began a volume at 00:22 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 00:00Z, 0.4 hours before the alert went out and 184 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: 2003 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 822 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -67 m²/s²
0-3 km storm-relative helicity: -65 m²/s²
Significant tornado parameter: -0.6
Supercell composite: -3.3

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 St. Louis, MO wrote its last area forecast discussion before this severe thunderstorm warning went out at May 7, 6:26 PM CDT, 55 minutes earlier.

Area forecast discussion, May 7, 6:26 PM CDT, 55 minutes before

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Hazardous weather outlook, May 7, 3:34 PM CDT, 3 hours 47 minutes before

Hazardous Weather Outlook
National Weather Service St Louis MO
334 PM CDT Sun May 7 2023

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-082045-
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL-
Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair IL-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
334 PM CDT Sun May 7 2023

This Hazardous Weather Outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Tonight.

There is a chance for thunderstorms through early this evening,
primarily across eastern Missouri and southwestern Illinois. A few
of the storms today could produce large hail and isolated wind gusts
to 60 mph. A few tornadoes are also possible, though less likely.

Another round of thunderstorms is likely after midnight tonight.
The primary threat from these storms will be wind gusts of 60-70 mph
across parts of northeast Missouri and west central Illinois. Large
hail is also possible but less likely. The threat for damaging winds
and large hail is lower, but still possible across the remainder of
the area late tonight as the storms move southeast.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Strong to severe thunderstorms are possible again on Monday,
primarily during the afternoon along and south of the I-70 corridor.
Large hail and damaging winds are the primary threats. A few
tornadoes are also possible, though less likely.

There is a chance for thunderstorms again for Thursday through next
Saturday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

Byrd

In the hours before

Local storm report, May 7, 6:18 PM CDT, 1 hour 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
618 PM CDT SUN MAY 7 2023

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

0618 PM     HAIL             HILLSBORO               39.16N 89.48W
05/07/2023  E1.00 INCH       MONTGOMERY         IL   TRAINED SPOTTER

&&

JPG

Local storm report, May 7, 6:26 PM CDT, 55 minutes before

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Local storm report, May 7, 6:46 PM CDT, 35 minutes before

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Local storm report, May 7, 6:47 PM CDT, 34 minutes before

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Local storm report, May 7, 7:01 PM CDT, 20 minutes before

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Local storm report, May 7, 7:18 PM CDT, 3 minutes before

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The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 8, 3:13 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Montgomery, Pike	47 min
May 8, 3:40 AM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Montgomery, Pike, Warren	34 min
May 8, 4:55 AM CDT	Severe Thunderstorm Warning	LSX	Franklin, Jefferson, Saint Louis	35 min
May 8, 4:14 PM CDT	Severe Thunderstorm Warning	LSX	Crawford	61 min
May 8, 5:09 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Reynolds	66 min
May 8, 6:11 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Iron, Reynolds	64 min
May 7, 7:19 PM CDT	Areal Flood Advisory	LSX	Bond, Fayette, Montgomery	3 hr
May 7, 10:13 PM CDT	Flash Flood Warning	LSX	Montgomery	6 hr
May 8, 12:15 AM CDT	Areal Flood Advisory	LSX	Fayette, Montgomery	6 hr
May 8, 11:00 AM CDT	River Flood Warning	LSX	Calhoun, Greene, Jersey	21 days

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.