Alert archive / Illinois / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 165, NWS St. Louis, MO

June 1, 2026Calhoun County, Greene County, Pike County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 1, 2026, 5:06 AM CDT for Calhoun County, Greene County, Pike County, Illinois. It was in force for 24 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jun 1, 2026, 5:06 AM CDT (10:06 UTC)
Expired: Jun 1, 2026, 5:30 AM CDT
In force: 24 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Calhoun County, IL, Greene County, IL, Pike County, IL

The radar

The St Louis radar (KLSX), 91 km from the middle of the area, began a volume at 10:06 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 1, 3:34 AM CDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 10.1 hours before the alert went out and 188 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: 2185 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 23 m²/s²
0-3 km storm-relative helicity: 342 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

390 
WUUS53 KLSX 011006
SVRLSX
ILC013-061-149-011045-
/O.NEW.KLSX.SV.W.0165.260601T1006Z-260601T1045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
506 AM CDT Mon Jun 1 2026

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  North Central Calhoun County in southwestern Illinois...
  Northwestern Greene County in southwestern Illinois...
  Southeastern Pike County in west central Illinois...

* Until 545 AM CDT.

* At 506 AM CDT, a severe thunderstorm was located 6 miles northeast
  of Pleasant Hill, or 8 miles south of Pittsfield, moving east at 35
  mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage to
           roofs, siding, and trees.

* Locations impacted include...
  Pleasant Hill, Martinsburg, Independence, Nebo, Time, Milton,
  Beecreek, Pearl, Bedford, Montezuma, Hillview, Haypress, Patterson,
  Walkersville and White Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds and large
hail.

&&

LAT...LON 3942 9090 3959 9089 3962 9060 3960 9060
      3960 9059 3956 9058 3954 9057 3953 9058
      3952 9058 3952 9041 3926 9042
TIME...MOT...LOC 1006Z 273DEG 31KT 3951 9079

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BAH

3 follow-up statements

718 
WWUS53 KLSX 011018
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
518 AM CDT Mon Jun 1 2026

ILC013-061-149-011045-
/O.CON.KLSX.SV.W.0165.000000T0000Z-260601T1045Z/
Calhoun IL-Greene IL-Pike IL-
518 AM CDT Mon Jun 1 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 AM CDT FOR
NORTH CENTRAL CALHOUN AND NORTHWESTERN GREENE COUNTIES IN
SOUTHWESTERN ILLINOIS AND SOUTHEASTERN PIKE COUNTY IN WEST CENTRAL
ILLINOIS...

At 518 AM CDT, a severe thunderstorm was located 12 miles southeast
of Pittsfield, moving east at 35 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to
         roofs, siding, and trees.

Locations impacted include...
  Nebo, Time, Milton, Beecreek, Pearl, Bedford, Montezuma, Hillview,
  Haypress, Patterson, Walkersville and White Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds and large
hail.

&&

LAT...LON 3939 9081 3960 9078 3962 9060 3960 9060
      3960 9059 3958 9058 3956 9058 3954 9057
      3953 9058 3952 9058 3952 9041 3926 9042
TIME...MOT...LOC 1006Z 273DEG 31KT 3951 9078

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BAH

412 
WWUS53 KLSX 011026
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
526 AM CDT Mon Jun 1 2026

ILC013-061-149-011045-
/O.CON.KLSX.SV.W.0165.000000T0000Z-260601T1045Z/
Calhoun IL-Greene IL-Pike IL-
526 AM CDT Mon Jun 1 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 AM CDT FOR
NORTH CENTRAL CALHOUN AND NORTHWESTERN GREENE COUNTIES IN
SOUTHWESTERN ILLINOIS AND SOUTHEASTERN PIKE COUNTY IN WEST CENTRAL
ILLINOIS...

At 526 AM CDT, a severe thunderstorm was located 9 miles west of
White Hall, moving east at 35 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to
         roofs, siding, and trees.

Locations impacted include...
  Milton, Pearl, Beecreek, Bedford, Montezuma, Hillview, Haypress,
  Walkersville, Patterson and White Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds and large
hail.

&&

LAT...LON 3938 9071 3961 9068 3962 9060 3960 9060
      3960 9059 3957 9058 3956 9058 3954 9057
      3953 9058 3952 9058 3952 9041 3926 9042
TIME...MOT...LOC 1018Z 275DEG 30KT 3945 9066

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BAH

690 
WWUS53 KLSX 011030
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
530 AM CDT Mon Jun 1 2026

ILC013-061-149-011040-
/O.CAN.KLSX.SV.W.0165.000000T0000Z-260601T1045Z/
Calhoun IL-Greene IL-Pike IL-
530 AM CDT Mon Jun 1 2026

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR NORTH CENTRAL CALHOUN
AND NORTHWESTERN GREENE COUNTIES IN SOUTHWESTERN ILLINOIS AND
SOUTHEASTERN PIKE COUNTY IN WEST CENTRAL ILLINOIS...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.

&&

LAT...LON 3938 9071 3961 9068 3962 9060 3960 9060
      3960 9059 3957 9058 3956 9058 3954 9057
      3953 9058 3952 9058 3952 9041 3926 9042
TIME...MOT...LOC 1026Z 275DEG 30KT 3944 9057

$$

BAH

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 Jun 1, 3:58 AM CDT, 1 hour 8 minutes earlier. Its key messages:

There will be two rounds of thunderstorms today, one early this morning and another over southeast Missouri and southwest Illinois this afternoon. Damaging winds, large hail, and heavy rainfall are possible with the strongest storms.
Dry weather is expected Tuesday through Thursday before the chances for showers and thunderstorms returns later this week into next weekend.

Area forecast discussion, Jun 1, 3:58 AM CDT, 1 hour 8 minutes before

Area Forecast Discussion
National Weather Service Saint Louis MO
358 AM CDT Mon Jun 1 2026

.KEY MESSAGES...

- There will be two rounds of thunderstorms today, one early this morning
  and another over southeast Missouri and southwest Illinois this
  afternoon. Damaging winds, large hail, and heavy rainfall are
  possible with the strongest storms.

- Dry weather is expected Tuesday through Thursday before the
  chances for showers and thunderstorms returns later this week
  into next weekend.

&&

.SHORT TERM...  (Through Late Tuesday Afternoon)
Issued at 356 AM CDT Mon Jun 1 2026

Thunderstorms continue to show a gradual increase in intensity
and severity early this morning on the nose of a broad low level
jet across Missouri. There remains the potential for severe
thunderstorms the remainder of the morning as the thunderstorms
over central and western Missouri develop a cold pool which could
cause upscale growth across the CWA into a line segment bringing
some damaging winds and hail with the stronger storms given the
current 1000-2500 MLCAPES and effective shear of 30-40 knots. The
environment this morning also remains favorable for storm
producing heavy rainfall given the current PWATS and warm cloud
depths, particularly if they can train in any one location for
very long.

The CAMS including the HRRR have this first round of convection
moving through the CWA by around 9-10 am.  It will lay out of the
outflow boundary that will allow for additional shower and
thunderstorm development this afternoon.  RAP soundings from
Farmington this afternoon are showing MLCAPES between 2000-3000 J/kg
with around 30 knots of deep layer shear.  This should be sufficient
to to produce an isolated threat for damaging winds and large hail
into the early evening hours.

Drier weather is expected from mid evening on as the HREF is showing
the high building down the upper Midwest.  Highs today will recover
back into the 80s behind this morning's storms but should be a few
degrees cooler tomorrow with cold air advection.
Britt

&&

.LONG TERM...  (Tuesday Night through Sunday)
Issued at 356 AM CDT Mon Jun 1 2026

Dry weather is still expected Wednesday into Thursday as the upper
ridge moves south across the area.  As the ridge continues to move
to the south, the chance of showers and thunderstorms will return to
the area late this week into the weekend as moisture returns north
into the area ahead of western trough.  High temperatures are
expected to return into the mid to high 80s.

Britt

&&

.AVIATION...  (For the 06z TAFs through 06z Monday Night)
Issued at 1106 PM CDT Sun May 31 2026

The focus for impacts this period continues to be showers and
thunderstorms through this morning. The main corridor for these
showers and thunderstorms will stretch from near KCOU and KJEF
east-southeastward through KSUS, KSTL, and KCPS. KUIN has a low
chance of being grazed by this activity, though confidence in this
occurring is dwindling. Storms will be capable of heavy rainfall
that will reduce visibilities to MVFR and even IFR flight
categories, and there is a very low chance for gusty, erratic
winds and small hail at KCOU and KJEF. Showers and thunderstorms
will move south of the local terminals by mid morning, with
confidence high in VFR flight conditions through the remainder of
the day.

Elmore

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

WFO LSX

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 1, 4:12 AM CDT	Severe Thunderstorm Warning	LSX	Randolph	34 min
Jun 1, 4:37 AM CDT	Flash Flood Warning	LSX	Calhoun, Greene, Jersey	5 hr
Jun 1, 5:57 AM CDT	Areal Flood Advisory	LSX	Madison, Saint Clair	3 hr
Jun 1, 6:37 AM CDT	Areal Flood Advisory	LSX	Saint Clair	4 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 2026 Every severe thunderstorm warning in 2026

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.