Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 140, NWS St. Louis, MO

August 8, 20214 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 8, 2021, 3:19 PM CDT for 4 counties in Missouri. It was in force for 41 min. 2 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 8, 2021, 3:19 PM CDT (20:19 UTC)
Expired
Aug 8, 2021, 4:00 PM CDT
In force
41 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Franklin County, MO, Lincoln County, MO, Saint Charles County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 17 km from the middle of the area, began a volume at 20:18 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 8, 3:20 PM CDTTSTM WND DMG3 Nw Marthasville, MOSEVERAL POWER LINES BLOWN DOWN BETWEEN HOPEWELL AND MARTHASVILLE.
Aug 8, 3:38 PM CDTTSTM WND DMGFlint Hill, MO4 INCH DIAMETER BRANCH DOWN.

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

The watch it was issued in

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

IssuedProductOfficeLasted
Aug 8, 12:44 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.3 hours before the alert went out and 240 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 12:00Z on 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 310 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 12:00Z on 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 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
310 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1165 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

128 
WUUS53 KLSX 082019
SVRLSX
MOC071-113-183-219-082100-
/O.NEW.KLSX.SV.W.0140.210808T2019Z-210808T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
319 PM CDT Sun Aug 8 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  St. Charles County in east central Missouri...
  Southeastern Lincoln County in east central Missouri...
  Central Franklin County in east central Missouri...
  Southeastern Warren County in east central Missouri...

* Until 400 PM CDT.

* At 318 PM CDT, severe thunderstorms were located along a line
  extending from Treloar to near Beaufort, moving northeast at 35
  mph.

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

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Marthasville around 325 PM CDT.
  Washington, Warrenton, Truesdale and Innsbrook around 335 PM CDT.

Other locations in the path of these severe thunderstorms include
Dutzow, Wright City, New Melle, Augusta, Wentzville, Defiance, Lake
St. Louis, St. Paul, Josephville, Fountain N' Lakes, Chain of Rocks
and Weldon Spring Heights.

This includes Interstate 70 in Missouri between exits 193 and 222.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in St Louis.

&&

LAT...LON 3905 9071 3901 9069 3896 9068 3895 9067
      3868 9058 3869 9066 3864 9073 3854 9074
      3841 9110 3868 9124 3890 9109 3906 9084
TIME...MOT...LOC 2018Z 231DEG 30KT 3865 9116 3843 9110 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Gosselin
2 follow-up statements
139 
WWUS53 KLSX 082040
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
340 PM CDT Sun Aug 8 2021

MOC071-082050-
/O.CAN.KLSX.SV.W.0140.000000T0000Z-210808T2100Z/
Franklin MO-
340 PM CDT Sun Aug 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL FRANKLIN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
southwestern Illinois...and east central Missouri.

LAT...LON 3905 9071 3868 9058 3869 9066 3863 9075
      3861 9076 3859 9078 3858 9082 3854 9090
      3854 9094 3857 9102 3860 9104 3861 9105
      3861 9108 3890 9109 3906 9084
TIME...MOT...LOC 2040Z 231DEG 30KT 3876 9099 3854 9093 

$$

MOC113-183-219-082100-
/O.CON.KLSX.SV.W.0140.000000T0000Z-210808T2100Z/
St. Charles MO-Lincoln MO-Warren MO-
340 PM CDT Sun Aug 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM CDT
FOR ST. CHARLES...SOUTHEASTERN LINCOLN AND SOUTHEASTERN WARREN
COUNTIES...

At 340 PM CDT, severe thunderstorms were located along a line
extending from near Innsbrook to near Augusta, moving northeast at 35
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
  Wright City, New Melle, Wentzville, Lake St. Louis, Josephville, 
  Defiance, St. Paul, Fountain N' Lakes, Chain of Rocks, Weldon 
  Spring Heights, O'Fallon, St. Peters, Dardenne Prairie, Weldon 
  Spring, Cottleville and Winfield.

This includes Interstate 70 in Missouri between exits 199 and 220.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

&&

LAT...LON 3905 9071 3868 9058 3869 9066 3863 9075
      3861 9076 3859 9078 3858 9082 3854 9090
      3854 9094 3857 9102 3860 9104 3861 9105
      3861 9108 3890 9109 3906 9084
TIME...MOT...LOC 2040Z 231DEG 30KT 3876 9099 3854 9093 

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

$$

Gosselin
625 
WWUS53 KLSX 082049
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
349 PM CDT Sun Aug 8 2021

MOC219-082059-
/O.CAN.KLSX.SV.W.0140.000000T0000Z-210808T2100Z/
Warren MO-
349 PM CDT Sun Aug 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WARREN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
southwestern Illinois...and east central Missouri.

LAT...LON 3905 9071 3868 9058 3869 9066 3863 9075
      3859 9078 3858 9082 3854 9090 3854 9094
      3855 9097 3887 9096 3887 9102 3894 9101
      3906 9084
TIME...MOT...LOC 2049Z 231DEG 30KT 3880 9093 3858 9087 

$$

MOC113-183-082100-
/O.CON.KLSX.SV.W.0140.000000T0000Z-210808T2100Z/
St. Charles MO-Lincoln MO-
349 PM CDT Sun Aug 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM CDT
FOR ST. CHARLES AND SOUTHEASTERN LINCOLN COUNTIES...

At 349 PM CDT, severe thunderstorms were located along a line
extending from near Wentzville to Augusta, moving northeast at 35
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
O'Fallon, St. Peters, Wentzville, Lake St. Louis, Dardenne Prairie,
Troy, Weldon Spring, Cottleville, St. Paul, Moscow Mills, Winfield,
New Melle, Josephville, Augusta, Fountain N' Lakes, Chain of Rocks,
Weldon Spring Heights, Defiance, Flint Hill and Foristell.

This includes Interstate 70 in Missouri between exits 203 and 220.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

&&

LAT...LON 3905 9071 3868 9058 3869 9066 3863 9075
      3859 9078 3858 9082 3854 9090 3854 9094
      3855 9097 3887 9096 3887 9102 3894 9101
      3906 9084
TIME...MOT...LOC 2049Z 231DEG 30KT 3880 9093 3858 9087 

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

$$

Gosselin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 2:37 PM CDTHeat AdvisoryLSXAudrain, Boone, Callaway, Cole, Crawford, Franklin and 23 more4 days
Aug 8, 2:43 PM CDTSevere Thunderstorm WarningLSXFranklin, Gasconade47 min
Aug 8, 3:54 PM CDTSevere Thunderstorm WarningLSXLincoln, Saint Charles66 min
Aug 8, 4:35 PM CDTAreal Flood AdvisoryLSXRalls3 hr

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.