Alert archive / Missouri / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 24, NWS St. Louis, MO
NWS St. Louis, MO issued this severe thunderstorm warning at Apr 7, 2021, 5:09 PM CDT for 6 counties in Missouri; Pike County, Illinois. It was in force for 19 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
- Apr 7, 2021, 5:09 PM CDT (22:09 UTC)
- Expired
- Apr 7, 2021, 5:28 PM CDT
- In force
- 19 min
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 0.88 in
- Wind
- 60.0 mph
Counties Pike County, IL, Knox County, MO, Lewis County, MO, Marion County, MO, Monroe County, MO, Ralls County, MO, Shelby County, MO
The radar
The St Louis radar (KLSX), 165 km from the middle of the area, began a volume at 22:08 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 |
|---|---|---|---|
| Apr 7, 5:10 PM CDT | TSTM WND DMG | Shelbyville, MO | LARGE TREE UPROOTED, SEVERAL SMALLER TREE LIMBS DOWNED. DAMAGE TO A MACHINE SHED. |
| Apr 7, 5:20 PM CDT | TSTM WND DMG | La Belle, MO | LAW ENFORCEMENT RECEIVED REPORT OF WINDS THAT TOOK TIN OFF OF A MOBILE HOME. |
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 |
|---|---|---|---|
| Apr 7, 12:02 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 10.2 hours before the alert went out and 212 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
- 7 J/kg
- Mixed-layer CIN
- -292 J/kg
- Mixed-layer LCL
- 1268 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 47 m²/s²
- 0-3 km storm-relative helicity
- 72 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
963
WUUS53 KLSX 072209
SVRLSX
ILC149-MOC103-111-127-137-173-205-072300-
/O.NEW.KLSX.SV.W.0024.210407T2209Z-210407T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
509 PM CDT Wed Apr 7 2021
The National Weather Service in St Louis has issued a
* Severe Thunderstorm Warning for...
Northwestern Pike County in west central Illinois...
Eastern Knox County in northeastern Missouri...
Northwestern Ralls County in northeastern Missouri...
Marion County in northeastern Missouri...
Shelby County in northeastern Missouri...
Lewis County in northeastern Missouri...
Eastern Monroe County in northeastern Missouri...
* Until 600 PM CDT.
* At 509 PM CDT, severe thunderstorms were located along a line
extending from 6 miles northeast of Clarence to Emden to near
Perry, moving northeast at 40 mph.
HAZARD...60 mph wind gusts and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Hannibal, Palmyra, Monroe City, Canton, Warren, La Grange, La
Belle, Shelbyville, Lewistown, Ewing, Rensselaer, Knox City,
Maywood, Spaulding, Plevna, Steffenville, Colony, Emden,
Philadelphia and Hunnewell.
This includes Interstate 72 near exit 4.
This also includes Wakonda State Park and Mark Twain Lake
Recreational Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4030 9195 4026 9193 4025 9150 4003 9150
3993 9142 3988 9145 3984 9144 3980 9137
3976 9136 3976 9124 3936 9179 3973 9198
3976 9229 3993 9229 4030 9208
TIME...MOT...LOC 2209Z 222DEG 36KT 3982 9221 3980 9190 3948 9174
TORNADO...POSSIBLE
HAIL...0.88IN
WIND...60MPH
$$
MRM2 follow-up statements
678
WWUS53 KLSX 072220
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
520 PM CDT Wed Apr 7 2021
ILC149-MOC103-111-127-137-173-205-072300-
/O.CON.KLSX.SV.W.0024.000000T0000Z-210407T2300Z/
Pike IL-Knox MO-Ralls MO-Marion MO-Shelby MO-Lewis MO-Monroe MO-
520 PM CDT Wed Apr 7 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR NORTHWESTERN PIKE COUNTY IN WEST CENTRAL ILLINOIS...EASTERN
KNOX...NORTHWESTERN RALLS...MARION...NORTHEASTERN SHELBY...LEWIS AND
EASTERN MONROE COUNTIES IN NORTHEASTERN MISSOURI...
At 520 PM CDT, severe thunderstorms were located along a line
extending from near Plevna to near Steffenville to near Monroe City,
moving northeast at 50 mph.
HAZARD...60 mph wind gusts and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Hannibal, Palmyra, Monroe City, Canton, Warren, La Grange, La Belle,
Lewistown, Ewing, Rensselaer, Knox City, Maywood, Spaulding, Plevna,
Steffenville, Colony, Emden, Philadelphia, Hunnewell and Taylor.
This also includes Wakonda State Park and Mark Twain Lake
Recreational Area.
This includes Interstate 72 near exit 4.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4030 9195 4026 9193 4025 9150 4003 9150
3993 9142 3988 9145 3984 9144 3980 9137
3976 9136 3976 9124 3936 9179 3981 9199
3993 9229 4030 9208
TIME...MOT...LOC 2220Z 208DEG 42KT 3993 9217 3991 9186 3959 9170
TORNADO...POSSIBLE
HAIL...0.88IN
WIND...60MPH
$$
MRM963
WWUS53 KLSX 072228
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
528 PM CDT Wed Apr 7 2021
ILC149-MOC103-111-127-137-173-205-072238-
/O.CAN.KLSX.SV.W.0024.000000T0000Z-210407T2300Z/
Pike IL-Knox MO-Ralls MO-Marion MO-Shelby MO-Lewis MO-Monroe MO-
528 PM CDT Wed Apr 7 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN PIKE COUNTY IN
WEST CENTRAL ILLINOIS...EASTERN KNOX...NORTHWESTERN RALLS...MARION...
NORTHEASTERN SHELBY...LEWIS AND EASTERN MONROE COUNTIES IN
NORTHEASTERN MISSOURI IS CANCELLED...
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 cancelled.
A Severe Thunderstorm Watch remains in effect until 700 PM CDT for
northeastern Missouri.
LAT...LON 4030 9195 4026 9193 4025 9150 4003 9150
3993 9142 3988 9145 3984 9144 3980 9137
3976 9136 3976 9124 3936 9179 3981 9199
3993 9229 4030 9208
TIME...MOT...LOC 2227Z 222DEG 36KT 3999 9210 3997 9179 3965 9163
$$
MRMThe office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 7, 3:06 PM CDT | Severe Thunderstorm Warning | LSX | Moniteau | 39 min |
| Apr 7, 4:04 PM CDT | Severe Thunderstorm Warning | LSX | Boone, Callaway, Cole, Moniteau, Osage | 26 min |
| Apr 7, 4:27 PM CDT | Areal Flood Advisory | LSX | Boone, Cole, Moniteau | 3 hr |
| Apr 7, 5:37 PM CDT | Severe Thunderstorm Warning | LSX | Franklin, Jefferson, Saint Francois, Washington | 68 min |
| Apr 7, 6:27 PM CDT | Severe Thunderstorm Warning | LSX | Saint Louis, City of Saint Louis | 49 min |
| Apr 7, 6:38 PM CDT | Severe Thunderstorm Warning | LSX | Adams, Brown | 17 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.