Alert archive / Missouri / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 146, NWS St. Louis, MO
NWS St. Louis, MO issued this severe thunderstorm warning at Aug 12, 2021, 5:51 PM CDT for 7 counties in Missouri; Calhoun County, Illinois. It was in force for 54 min. 26 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 12, 2021, 5:51 PM CDT (22:51 UTC)
- Expired
- Aug 12, 2021, 6:45 PM CDT
- In force
- 54 min
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Calhoun County, IL, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Lincoln County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 21 km from the middle of the area, began a volume at 22:51 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 12, 5:58 PM CDT | TSTM WND DMG | 1 Wsw Truesdale, MO | CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 1 W NEW MELLE, LOCATION CORRECTED TO WARRENTON. PORTION OF FLAT ROOF PEELED OFF OF ELEMENTARY SCHOOL, TIME ESTIMATED FROM RADAR. |
| Aug 12, 6:01 PM CDT | TSTM WND DMG | Winfield, MO | 3-5 INCH TREE LIMB DOWN. |
| Aug 12, 6:02 PM CDT | TSTM WND DMG | 2 Ene Foristell, MO | LARGE TREE BLOWN OVER ONTO W. MEYER ROAD IN WENTZVILLE. |
| Aug 12, 6:04 PM CDT | TSTM WND DMG | 2 Wnw Wentzville, MO | SEVERAL LARGE TREE BRANCHES DOWN. |
| Aug 12, 6:04 PM CDT | TSTM WND DMG | New Melle, MO | PORTION OF FLAT ROOF PEELED OFF OF ELEMENTARY SCHOOL |
| Aug 12, 6:04 PM CDT | TSTM WND DMG | New Melle, MO | PORTION OF FLAT ROOF PEELED OFF OF ELEMENTARY SCHOOL. |
| Aug 12, 6:04 PM CDT | TSTM WND GST 52 | Flint Hill, MO | NEAR INTERSECTION OF US HIGHWAY 61 AND HIGHWAY P. |
| Aug 12, 6:05 PM CDT | TSTM WND GST 64 | 2 Wsw Wentzville, MO | MODOT OBSERVATION SITE ON INTERSTATE 70. |
| Aug 12, 6:14 PM CDT | TSTM WND DMG | 2 E O'Fallon, MO | SEVERAL TREES BLOWN DOWN NEAR INTERSECTION OF MEXICO ROAD AND BELLEAU CREEK ROAD. |
| Aug 12, 6:15 PM CDT | TSTM WND DMG | 2 E Dardenne Prairie, MO | SEVERAL TREES BLOWN DOWN NEAR INTERSECTION OF HIGHWAYS N AND K. |
| Aug 12, 6:21 PM CDT | TSTM WND DMG | 1 Nne Defiance, MO | TREE AND POWER LINE BLOWN DOWN OVER HIGHWAY DD NEAR INTERSECTION WITH HIGHWAY 94. |
| Aug 12, 6:21 PM CDT | TSTM WND DMG | 3 Nw Gray Summit, MO | GUST FRONT WINDS BLEW DOWN SEVERAL TREES AND POWER LINES DOWN AROUND LABADIE. |
| Aug 12, 6:24 PM CDT | TSTM WND DMG | 2 Nne Gray Summit, MO | 3 TO 4 INCH DIAMETER TREE LIMBS DOWN. |
| Aug 12, 6:25 PM CDT | TSTM WND GST 56 | 4 Nw Clarkson Valley, MO | MEASURED KSUS ASOS. |
| Aug 12, 6:29 PM CDT | TSTM WND DMG | 1 Ene Eureka, MO | SHINGLES BLOWN OFF OF A FEW HOUSES. |
| Aug 12, 6:34 PM CDT | TSTM WND DMG | Florissant, MO | LARGE LIMBS DOWN ON HOUSE. |
| Aug 12, 6:34 PM CDT | TSTM WND GST 55 | 2 Ene Maryland Heights, MO | |
| Aug 12, 6:37 PM CDT | TSTM WND DMG | 1 N Kirkwood, MO | SEVERAL TREES AND NUMEROUS TREE LIMBS WERE BLOWN DOWN NEAR THE INTERSECTION OF MANCHESTER ROAD AND GEYER ROAD. |
| Aug 12, 6:37 PM CDT | TSTM WND DMG | Kirkwood, MO | SEVERAL TREES AND NUMEROUS TREE LIMBS BLOWN DOWN NEAR THE INTERSECTION OF MANCHESTER ROAD AND GEYER ROAD. |
| Aug 12, 6:39 PM CDT | TSTM WND GST 58 | 1 Wnw Berkeley, MO | CORRECTS PREVIOUS TSTM WND GST REPORT FROM 1 WNW BERKELEY. WIND GUST REPORTED AT ST. LOUIS-LAMBERT INTERNATIONAL AIRPORT. |
| Aug 12, 6:41 PM CDT | TSTM WND DMG | Brentwood, MO | LARGE TREE SNAPPED IN HALF CAUSING DAMAGE TO A HOUSE ON PINE AVENUE NEAR THE INTERSECTION WITH ST. CLAIR IN BRENTWOOD. |
| Aug 12, 6:41 PM CDT | TSTM WND DMG | Murphy, MO | POWER LINES DOWN AND MULTIPLE TREES SNAPPED. |
| Aug 12, 6:42 PM CDT | TSTM WND GST 58 | 1 Wnw Berkeley, MO | WIND GUST REPORTED AT ST. LOUIS-LAMBERT INTERNATIONAL AIRPORT. |
| Aug 12, 6:54 PM CDT | TSTM WND DMG | Normandy, MO | LIMBS DOWN |
| Aug 12, 6:54 PM CDT | TSTM WND DMG | Normandy, MO | LIMBS DOWN. |
| Aug 12, 6:55 PM CDT | TSTM WND GST 58 | 1 Ssw Hazelwood, MO |
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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 12, 5:19 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 10.9 hours before the alert went out and 252 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.
- Mixed-layer CAPE
- 1191 J/kg
- Mixed-layer CIN
- -177 J/kg
- Mixed-layer LCL
- 1149 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 140 m²/s²
- 0-3 km storm-relative helicity
- 128 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.1
The text
As transmitted.
272
WUUS53 KLSX 122251
SVRLSX
ILC013-MOC071-073-099-113-183-189-219-122345-
/O.NEW.KLSX.SV.W.0146.210812T2251Z-210812T2345Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
551 PM CDT Thu Aug 12 2021
The National Weather Service in St Louis has issued a
* Severe Thunderstorm Warning for...
Southeastern Calhoun County in southwestern Illinois...
St. Charles County in east central Missouri...
Northwestern Jefferson County in east central Missouri...
Southeastern Lincoln County in east central Missouri...
Franklin County in east central Missouri...
St. Louis County in east central Missouri...
Warren County in east central Missouri...
Northern Gasconade County in east central Missouri...
* Until 645 PM CDT.
* At 551 PM CDT, severe thunderstorms were located along a line
extending from near Davis to near Treloar to near Mount Sterling,
moving southeast at 40 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...This line of storms has a history of wind damage.
IMPACT...Expect damage to roofs, siding, and trees.
* Severe thunderstorms will be near...
Marthasville and Fountain N' Lakes around 600 PM CDT.
Washington, Winfield, Chain of Rocks and Dutzow around 605 PM CDT.
Gerald around 610 PM CDT.
Other locations in the path of these severe thunderstorms include
Augusta, Villa Ridge, Defiance, Beaufort, Gray Summit, St. Charles,
Oak Grove, Sullivan, Pacific, Orchard Farms, Maryland Heights,
Eureka, Portage Des Sioux and Miramiguoa Park.
This includes the following highways...
Interstate 44 in Missouri between exits 228 and 277.
Interstate 70 in Missouri between exits 188 and 231.
This also includes Babler Memorial State Park, Route 66 State Park,
Deutschheim Historic Site, Castlewood State Park, First Missouri
State Capitol Historic Site, and Robertsville State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3885 9130 3885 9126 3891 9123 3885 9100
3905 9076 3899 9057 3896 9053 3897 9049
3888 9020 3841 9046 3828 9079 3820 9130
3850 9164
TIME...MOT...LOC 2251Z 296DEG 36KT 3905 9092 3869 9115 3844 9156
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Elmore4 follow-up statements
814
WWUS53 KLSX 122258
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
558 PM CDT Thu Aug 12 2021
ILC013-MOC071-073-099-113-183-189-219-122345-
/O.CON.KLSX.SV.W.0146.000000T0000Z-210812T2345Z/
Calhoun IL-St. Charles MO-Jefferson MO-Lincoln MO-Franklin MO-
St. Louis MO-Warren MO-Gasconade MO-
558 PM CDT Thu Aug 12 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR SOUTHEASTERN CALHOUN...ST. CHARLES...NORTHWESTERN JEFFERSON...
SOUTHEASTERN LINCOLN...FRANKLIN...ST. LOUIS...WARREN AND NORTHERN
GASCONADE COUNTIES...
At 557 PM CDT, severe thunderstorms were located along a line
extending from near Fountain N' Lakes to near Marthasville to near
Drake, moving east at 40 mph.
HAZARD...70 mph wind gusts and penny size hail.
SOURCE...This line of storms has downed trees and snapped power
poles.
IMPACT...Expect considerable tree damage. Damage is likely to mobile
homes, roofs, and outbuildings.
These severe storms will be near...
Washington, Marthasville and Fountain N' Lakes around 600 PM CDT.
Winfield, Innsbrook and Dutzow around 605 PM CDT.
Gerald around 610 PM CDT.
Other locations in the path of these severe thunderstorms include New
Melle, Augusta, Defiance, Dardenne Prairie, Beaufort, O'Fallon,
Wildwood, Spirit of St. Louis Airport, Weldon Spring Heights, St.
Peters, Union, Weldon Spring, Cottleville and Clarkson Valley.
This also includes Babler Memorial State Park, Route 66 State Park,
Deutschheim Historic Site, Castlewood State Park, First Missouri
State Capitol Historic Site, and Robertsville State Park.
This includes the following highways...
Interstate 44 in Missouri between exits 228 and 277.
Interstate 70 in Missouri between exits 188 and 231.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3885 9130 3885 9126 3891 9123 3885 9100
3905 9076 3899 9057 3896 9053 3897 9049
3888 9020 3841 9046 3828 9079 3820 9130
3850 9164
TIME...MOT...LOC 2257Z 270DEG 36KT 3903 9087 3867 9110 3842 9151
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH
$$
Elmore889
WWUS53 KLSX 122315
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
615 PM CDT Thu Aug 12 2021
ILC013-MOC071-073-099-113-183-189-219-122345-
/O.CON.KLSX.SV.W.0146.000000T0000Z-210812T2345Z/
Calhoun IL-St. Charles MO-Jefferson MO-Lincoln MO-Franklin MO-
St. Louis MO-Warren MO-Gasconade MO-
615 PM CDT Thu Aug 12 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR SOUTHEASTERN CALHOUN...ST. CHARLES...NORTHWESTERN JEFFERSON...
SOUTHEASTERN LINCOLN...FRANKLIN...ST. LOUIS...SOUTHEASTERN WARREN AND
EAST CENTRAL GASCONADE COUNTIES...
At 615 PM CDT, severe thunderstorms were located along a line
extending from near Winfield to near Augusta to near Gerald, moving
east at 40 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...This line of storms has a history of producing wind damage.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Winfield, New Melle, Augusta, Pacific, Defiance, Wildwood,
Sullivan, Weldon Spring Heights, Orchard Farms, Eureka, Spirit of
St. Louis Airport, Ballwin, Union, Ellisville, St. Clair, Clarkson
Valley, Parkway, Portage Des Sioux, Chesterfield, Manchester, Town
and Country, Winchester, West Alton, Twin Oaks, Kirkwood, Des
Peres, Valley Park, Fenton, Murphy, Crystal Lake Park, Westwood,
Country Life Acres, Webster Groves, Creve Coeur, Overland,
Crestwood, Ladue, Sunset Hills, Brentwood, Olivette, Glendale and
Frontenac.
This also includes Babler Memorial State Park, Route 66 State Park,
Castlewood State Park, First Missouri State Capitol Historic Site,
and Robertsville State Park.
This includes the following highways...
Interstate 44 in Missouri between exits 228 and 277.
Interstate 70 in Missouri between exits 200 and 231.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3865 9122 3885 9100 3905 9076 3899 9057
3896 9053 3897 9049 3888 9020 3841 9046
3828 9079 3820 9130 3841 9154
TIME...MOT...LOC 2315Z 270DEG 36KT 3897 9066 3861 9089 3836 9130
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Elmore498
WWUS53 KLSX 122329
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
629 PM CDT Thu Aug 12 2021
MOC073-113-122337-
/O.CAN.KLSX.SV.W.0146.000000T0000Z-210812T2345Z/
Lincoln MO-Gasconade MO-
629 PM CDT Thu Aug 12 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LINCOLN AND EAST
CENTRAL GASCONADE COUNTIES IS CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
southwestern Illinois...and east central Missouri.
LAT...LON 3889 9095 3887 9082 3892 9078 3892 9069
3893 9070 3894 9066 3903 9070 3899 9057
3896 9053 3897 9048 3888 9020 3841 9046
3828 9079 3820 9130 3825 9136 3826 9137
3854 9137
TIME...MOT...LOC 2327Z 296DEG 36KT 3893 9055 3857 9078 3832 9119
$$
ILC013-MOC071-099-183-189-219-122345-
/O.CON.KLSX.SV.W.0146.000000T0000Z-210812T2345Z/
Calhoun IL-St. Charles MO-Jefferson MO-Franklin MO-St. Louis MO-
Warren MO-
629 PM CDT Thu Aug 12 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR SOUTHEASTERN CALHOUN...ST. CHARLES...NORTHWESTERN JEFFERSON...
FRANKLIN...ST. LOUIS AND SOUTHEASTERN WARREN COUNTIES...
At 627 PM CDT, severe thunderstorms were located along a line
extending from 6 miles northwest of Orchard Farms to near Defiance to
7 miles south of Beaufort, moving southeast at 40 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...This line of storms has a history of wind damage.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
O'Fallon, St. Charles, St. Peters, Florissant, Chesterfield,
Wildwood, University City, Ballwin, Wentzville, Kirkwood, Maryland
Heights, Hazelwood, Webster Groves, Ferguson, Manchester, Creve
Coeur, Overland, Clayton, Jennings and Lake St. Louis.
This also includes Babler Memorial State Park, Route 66 State Park,
Castlewood State Park, First Missouri State Capitol Historic Site,
and Robertsville State Park.
This includes the following highways...
Interstate 44 in Missouri between exits 228 and 277.
Interstate 70 in Missouri between exits 200 and 231.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3889 9095 3887 9082 3892 9078 3892 9069
3893 9070 3894 9066 3903 9070 3899 9057
3896 9053 3897 9048 3888 9020 3841 9046
3828 9079 3820 9130 3825 9136 3826 9137
3854 9137
TIME...MOT...LOC 2327Z 296DEG 36KT 3893 9055 3857 9078 3832 9119
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Elmore557
WWUS53 KLSX 122342
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
642 PM CDT Thu Aug 12 2021
ILC013-MOC071-099-183-189-219-122352-
/O.EXP.KLSX.SV.W.0146.000000T0000Z-210812T2345Z/
Calhoun IL-St. Charles MO-Jefferson MO-Franklin MO-St. Louis MO-
Warren MO-
642 PM CDT Thu Aug 12 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CALHOUN...ST.
CHARLES...NORTHWESTERN JEFFERSON...FRANKLIN...ST. LOUIS AND
SOUTHEASTERN WARREN COUNTIES WILL EXPIRE AT 645 PM CDT...
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
southwestern Illinois...and east central Missouri.
LAT...LON 3889 9095 3887 9082 3892 9078 3892 9069
3893 9070 3894 9066 3903 9070 3899 9057
3896 9053 3897 9048 3888 9020 3841 9046
3828 9079 3820 9130 3825 9136 3826 9137
3854 9137
TIME...MOT...LOC 2342Z 296DEG 36KT 3887 9039 3851 9062 3826 9103
$$
ElmoreThe office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 3:58 PM CDT | Severe Thunderstorm Warning | LSX | Audrain, Boone, Monroe, Shelby | 62 min |
| Aug 12, 4:45 PM CDT | Severe Thunderstorm Warning | LSX | Marion, Pike, Ralls | 45 min |
| Aug 12, 4:50 PM CDT | Severe Thunderstorm Warning | LSX | Audrain, Callaway, Lincoln, Monroe, Montgomery, Pike and 1 more | 40 min |
| Aug 12, 4:56 PM CDT | Areal Flood Advisory | LSX | Lewis, Marion | 4 hr |
| Aug 12, 5:27 PM CDT | Severe Thunderstorm Warning | LSX | Audrain, Lincoln, Montgomery, Pike, Warren | 48 min |
| Aug 12, 6:37 PM CDT | Severe Thunderstorm Warning | LSX | Franklin, Jefferson, Saint Charles, Saint Louis, City of Saint Louis | 53 min |
| Aug 12, 6:41 PM CDT | Areal Flood Advisory | LSX | Lincoln, Saint Charles, Saint Louis | 4 hr |
| Aug 12, 5:28 PM CDT | Areal Flood Advisory | LSX | Bond, Madison | 4 hr |
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.