Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 161, 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, 9:03 PM CDT for Saint Francois County, Washington County, Missouri. It was in force for 42 min. 5 reports 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, 9:03 PM CDT (02:03 UTC)
Expired
Aug 31, 2021, 9:45 PM CDT
In force
42 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), 80 km from the middle of the area, began a volume at 02:02 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, 9:05 PM CDTTSTM WND DMG1 Ese Old Mines, MOTREE DOWN AT HIGHWAY 21 AND HIGHWAY 47.
Aug 31, 9:05 PM CDTTSTM WND DMG1 S Old Mines, MOPOWER LINE KNOCKED OVER ALONG HIGHWAY 21.
Aug 31, 9:07 PM CDTTSTM WND GST 60Old Mines, MOALSO, VERY HEAVY RAINFALL.
Aug 31, 9:23 PM CDTTSTM WND DMG2 Wnw Frankclay, MOTREE DOWN AT HIGHWAY 8 AND GERMANIA.
Aug 31, 9:26 PM CDTTSTM WND DMG2 Sw Bonne Terre, MOEMERGENCY MANAGER REPORTED 50-60 ESTIMATED WINDS. SOME SIDING FROM A NEIGHBOR WAS BLOWN INTO THEIR YARD.

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, 2.1 hours before the alert went out and 292 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.

779 
WUUS53 KLSX 010203
SVRLSX
MOC187-221-010245-
/O.NEW.KLSX.SV.W.0161.210901T0203Z-210901T0245Z/

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

The National Weather Service in St Louis has issued a

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

* Until 945 PM CDT.

* At 902 PM CDT, a severe thunderstorm was located over Old Mines,
  moving south at 25 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Potosi, Leadwood, Irondale, Mineral Point, Old Mines, Frankclay and
  Cadet.

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 3807 9091 3812 9070 3785 9058 3780 9084
TIME...MOT...LOC 0202Z 343DEG 21KT 3805 9079 

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

$$

Byrd
1 follow-up statement
985 
WWUS53 KLSX 010227
SVSLSX

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

MOC187-221-010245-
/O.CON.KLSX.SV.W.0161.000000T0000Z-210901T0245Z/
Washington MO-St. Francois MO-
927 PM CDT Tue Aug 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT
FOR SOUTHEASTERN WASHINGTON AND WEST CENTRAL ST. FRANCOIS COUNTIES...

At 927 PM CDT, a severe thunderstorm was located over Mineral Point,
moving south at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Potosi, Leadwood, Irondale and Frankclay. 

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 3789 9081 3799 9064 3785 9058 3780 9084
TIME...MOT...LOC 0227Z 343DEG 21KT 3791 9074 

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

$$

Byrd

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 9:31 PM CDTSevere Thunderstorm WarningLSXSaint Francois, Washington44 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.