Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 162, NWS St. Louis, MO

August 31, 2021Saint Francois County, Washington County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 31, 2021, 9:31 PM CDT for Saint Francois County, Washington County, Missouri. It was in force for 44 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
Aug 31, 2021, 9:31 PM CDT (02:31 UTC)
Expired
Aug 31, 2021, 10:15 PM CDT
In force
44 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Saint Francois County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 103 km from the middle of the area, began a volume at 02:32 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
Aug 31, 9:33 PM CDTTSTM WND DMG3 Nne Bismarck, MOTREE DOWN OVER HIGHWAY 32 AND OLD IRONDALE ROAD.

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

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 2.5 hours before the alert went out and 302 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, Springfield, MO at 00:00Z on 2021-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 208 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, Springfield, MO at 00:00Z on 2021-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
208 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
1625 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

338 
WUUS53 KLSX 010231
SVRLSX
MOC187-221-010315-
/O.NEW.KLSX.SV.W.0162.210901T0231Z-210901T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
931 PM CDT Tue Aug 31 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southeastern Washington County in east central Missouri...
  St. Francois County in southeastern Missouri...

* Until 1015 PM CDT.

* At 930 PM CDT, a severe thunderstorm was located over Leadwood,
  moving southeast at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Farmington, Bonne Terre, Desloge, Bismarck, Leadwood, Park Hills,
  Iron Mountain Lake, Irondale, Knob Lick, Iron Mountain, Leadington,
  Libertyville, Frankclay and Doe Run.

This also includes St. Joe State Park and Missouri Mines Historic
Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3768 9065 3773 9065 3774 9068 3790 9077
      3801 9058 3789 9045 3788 9046 3765 9019
      3764 9063
TIME...MOT...LOC 0230Z 326DEG 26KT 3789 9062 

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

$$

Byrd
2 follow-up statements
900 
WWUS53 KLSX 010254
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
954 PM CDT Tue Aug 31 2021

MOC221-010303-
/O.CAN.KLSX.SV.W.0162.000000T0000Z-210901T0315Z/
Washington MO-
954 PM CDT Tue Aug 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WASHINGTON COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3768 9065 3782 9063 3793 9050 3789 9045
      3788 9046 3765 9019 3764 9063
TIME...MOT...LOC 0253Z 326DEG 26KT 3775 9050 

$$

MOC187-010315-
/O.CON.KLSX.SV.W.0162.000000T0000Z-210901T0315Z/
St. Francois MO-
954 PM CDT Tue Aug 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT
FOR ST. FRANCOIS COUNTY...

At 953 PM CDT, a severe thunderstorm was located near Farmington,
moving southeast at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Farmington, Bonne Terre, Desloge, Bismarck, Leadwood, Park Hills,
Iron Mountain Lake, Iron Mountain, Knob Lick, Leadington,
Libertyville and Doe Run.

This also includes St. Joe State Park and Missouri Mines Historic
Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3768 9065 3782 9063 3793 9050 3789 9045
      3788 9046 3765 9019 3764 9063
TIME...MOT...LOC 0253Z 326DEG 26KT 3775 9050 

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

$$

Byrd
538 
WWUS53 KLSX 010311
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1011 PM CDT Tue Aug 31 2021

MOC187-010321-
/O.EXP.KLSX.SV.W.0162.000000T0000Z-210901T0315Z/
St. Francois MO-
1011 PM CDT Tue Aug 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR ST. FRANCOIS COUNTY WILL
EXPIRE AT 1015 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 3768 9065 3782 9063 3793 9050 3789 9045
      3788 9046 3765 9019 3764 9063
TIME...MOT...LOC 0311Z 326DEG 26KT 3765 9041 

$$

Byrd

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 9:03 PM CDTSevere Thunderstorm WarningLSXSaint Francois, Washington42 min
Aug 31, 9:49 PM CDTSevere Thunderstorm WarningLSXIron, Madison, Reynolds, Saint Francois41 min

Nearby

Severe Thunderstorm Warnings in Missouri, 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.