Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 167, NWS St. Louis, MO

September 20, 2021Marion County, Pike County, Ralls County, Missouri; Adams County, Pike County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Sep 20, 2021, 10:35 PM CDT for Marion County, Pike County, Ralls County, Missouri; Adams County, Pike County, Illinois. It was in force for 40 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 20, 2021, 10:35 PM CDT (03:35 UTC)
Expired
Sep 20, 2021, 11:15 PM CDT
In force
40 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Adams County, IL, Pike County, IL, Marion County, MO, Pike County, MO, Ralls County, MO

The radar

The St Louis radar (KLSX), 108 km from the middle of the area, began a volume at 03:35 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.

What was reported inside it

TimeReportWhereRemark
Sep 20, 11:00 PM CDTTSTM WND DMG2 N Bowling Green, MOTREE BLOWN DOWN ONTO CAR. REPORTED BY BOWLING GREEN PD. TIME ESTIMATED BY RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 3.6 hours before the alert went out and 223 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, Lincoln, IL at 00:00Z on 2021-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 766 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2021-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
766 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
1264 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.6

Open this sounding in Storm Lab

The text

As transmitted.

827 
WUUS53 KLSX 210335
SVRLSX
ILC001-149-MOC127-163-173-210415-
/O.NEW.KLSX.SV.W.0167.210921T0335Z-210921T0415Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
1035 PM CDT Mon Sep 20 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Pike County in west central Illinois...
  Southeastern Adams County in west central Illinois...
  Northern Ralls County in northeastern Missouri...
  Southeastern Marion County in northeastern Missouri...
  Northwestern Pike County in northeastern Missouri...

* Until 1115 PM CDT.

* At 1035 PM CDT, severe thunderstorms were located along a line
  extending from near Monroe City to near Center to near Vandalia,
  moving east at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Curryville and Spencerburg around 1045 PM CDT.
  New London, Frankford, Rensselaer and Spaulding around 1050 PM 
  CDT.
  Tarrants around 1055 PM CDT.

Other locations in the path of these severe thunderstorms include
Hannibal, Fall Creek, Louisiana, Payson, Pike, Barry, Pleasant Hill
and Atlas.

This includes the following highways...
 Interstate 172 near exit 2.
 Interstate 72 between exits 4 and 35.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3971 9077 3944 9065 3932 9143 3950 9147
      3966 9172 3993 9103
TIME...MOT...LOC 0335Z 251DEG 41KT 3962 9172 3950 9158 3937 9152 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Britt
2 follow-up statements
418 
WWUS53 KLSX 210400
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1100 PM CDT Mon Sep 20 2021

ILC001-149-MOC127-163-173-210415-
/O.CON.KLSX.SV.W.0167.000000T0000Z-210921T0415Z/
Pike IL-Adams IL-Ralls MO-Marion MO-Pike MO-
1100 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT
FOR PIKE AND SOUTHEASTERN ADAMS COUNTIES IN WEST CENTRAL ILLINOIS...
NORTHEASTERN RALLS...SOUTHEASTERN MARION AND NORTHWESTERN PIKE
COUNTIES IN NORTHEASTERN MISSOURI...

At 1100 PM CDT, severe thunderstorms were located along a line
extending from near Hannibal to 7 miles northeast of Frankford to
near Tarrants, moving east at 50 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Louisiana, Payson, Pike, Barry, Pleasant Hill, Atlas, Beverly and 
  Pittsfield.

This includes the following highways...
 Interstate 172 near exit 2.
 Interstate 72 between exits 4 and 35.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3971 9077 3944 9065 3934 9133 3954 9139
      3972 9157 3993 9103
TIME...MOT...LOC 0400Z 251DEG 43KT 3971 9134 3959 9124 3941 9121 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Britt
212 
WWUS53 KLSX 210415
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1115 PM CDT Mon Sep 20 2021

ILC001-149-MOC127-163-173-210425-
/O.EXP.KLSX.SV.W.0167.000000T0000Z-210921T0415Z/
Pike IL-Adams IL-Ralls MO-Marion MO-Pike MO-
1115 PM CDT Mon Sep 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR PIKE AND SOUTHEASTERN ADAMS
COUNTIES IN WEST CENTRAL ILLINOIS...NORTHEASTERN RALLS...SOUTHEASTERN
MARION AND NORTHWESTERN PIKE COUNTIES IN NORTHEASTERN MISSOURI HAS
EXPIRED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been allowed to expire.

LAT...LON 3971 9077 3944 9065 3934 9133 3954 9139
      3972 9157 3993 9103
TIME...MOT...LOC 0415Z 251DEG 41KT 3976 9114 3964 9104 3946 9101 

$$

Britt

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 8:45 PM CDTSevere Thunderstorm WarningLSXKnox, Lewis45 min
Sep 20, 9:56 PM CDTSevere Thunderstorm WarningLSXAudrain, Monroe, Ralls51 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2021Severe Thunderstorm Warnings in Illinois, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.