Alert archive / Missouri / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 7, NWS St. Louis, MO
NWS St. Louis, MO issued this severe thunderstorm warning at Mar 27, 2021, 4:16 PM CDT for 4 counties in Missouri. It was in force for 44 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
- Mar 27, 2021, 4:16 PM CDT (21:16 UTC)
- Expired
- Mar 27, 2021, 5:00 PM CDT
- In force
- 44 min
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Franklin County, MO, Gasconade County, MO, Saint Charles County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 33 km from the middle of the area, began a volume at 21:18 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Mar 27, 4:47 PM CDT | HAIL 0.25 | Marthasville, MO | |
| Mar 27, 4:48 PM CDT | HAIL 0.25 | 1 S New Melle, MO |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 9.3 hours before the alert went out and 265 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1078 m above ground
- 0-6 km bulk shear
- 78 kt
- 0-1 km storm-relative helicity
- 369 m²/s²
- 0-3 km storm-relative helicity
- 384 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
940
WUUS53 KLSX 272116
SVRLSX
MOC071-073-183-219-272200-
/O.NEW.KLSX.SV.W.0007.210327T2116Z-210327T2200Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
416 PM CDT Sat Mar 27 2021
The National Weather Service in St Louis has issued a
* Severe Thunderstorm Warning for...
Southwestern St. Charles County in east central Missouri...
Northwestern Franklin County in east central Missouri...
Southeastern Warren County in east central Missouri...
Northeastern Gasconade County in east central Missouri...
* Until 500 PM CDT.
* At 415 PM CDT, a severe thunderstorm was located near Swiss, moving
northeast at 50 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
O'Fallon, Wentzville, Lake St. Louis, Washington, Dardenne Prairie,
New Haven, Marthasville, Innsbrook, New Melle, Josephville, Swiss,
Treloar, Dutzow, Defiance, Flint Hill, Foristell, Lyon and
Holstein.
This includes Interstate 70 in Missouri between exits 203 and 212.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3857 9152 3888 9085 3888 9083 3887 9082
3888 9081 3865 9071 3841 9141
TIME...MOT...LOC 2115Z 243DEG 44KT 3852 9137
HAIL...1.00IN
WIND...60MPH
$$
BRC2 follow-up statements
896
WWUS53 KLSX 272129
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
429 PM CDT Sat Mar 27 2021
MOC073-272138-
/O.CAN.KLSX.SV.W.0007.000000T0000Z-210327T2200Z/
Gasconade MO-
429 PM CDT Sat Mar 27 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN GASCONADE COUNTY
IS CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
LAT...LON 3888 9085 3888 9083 3887 9082 3888 9081
3865 9071 3848 9130 3858 9137 3863 9137
TIME...MOT...LOC 2128Z 243DEG 44KT 3860 9118
$$
MOC071-183-219-272200-
/O.CON.KLSX.SV.W.0007.000000T0000Z-210327T2200Z/
St. Charles MO-Franklin MO-Warren MO-
429 PM CDT Sat Mar 27 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR SOUTHWESTERN ST. CHARLES...NORTHWESTERN FRANKLIN AND SOUTHEASTERN
WARREN COUNTIES...
At 428 PM CDT, a severe thunderstorm was located over New Haven,
moving northeast at 50 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
O'Fallon, Wentzville, Lake St. Louis, Washington, Dardenne Prairie,
New Haven, Marthasville, Innsbrook, New Melle, Josephville, Treloar,
Dutzow, Defiance, Flint Hill, Foristell and Holstein.
This includes Interstate 70 in Missouri between exits 203 and 212.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3888 9085 3888 9083 3887 9082 3888 9081
3865 9071 3848 9130 3858 9137 3863 9137
TIME...MOT...LOC 2128Z 243DEG 44KT 3860 9118
HAIL...1.00IN
WIND...60MPH
$$
BRC197
WWUS53 KLSX 272144
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
444 PM CDT Sat Mar 27 2021
MOC071-272153-
/O.CAN.KLSX.SV.W.0007.000000T0000Z-210327T2200Z/
Franklin MO-
444 PM CDT Sat Mar 27 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN FRANKLIN COUNTY
IS CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
east central Missouri.
LAT...LON 3888 9085 3888 9083 3887 9082 3888 9081
3865 9071 3856 9101 3860 9104 3861 9105
3861 9108 3860 9113 3862 9123 3865 9123
3868 9127
TIME...MOT...LOC 2143Z 243DEG 44KT 3869 9096
$$
MOC183-219-272200-
/O.CON.KLSX.SV.W.0007.000000T0000Z-210327T2200Z/
St. Charles MO-Warren MO-
444 PM CDT Sat Mar 27 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR SOUTHWESTERN ST. CHARLES AND SOUTHEASTERN WARREN COUNTIES...
At 443 PM CDT, a severe thunderstorm was located near New Melle,
moving northeast at 50 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
O'Fallon, Wentzville, Lake St. Louis, Dardenne Prairie, New Haven,
Marthasville, Innsbrook, New Melle, Josephville, Treloar, Dutzow,
Defiance, Flint Hill, Foristell and Holstein.
This includes Interstate 70 in Missouri between exits 203 and 212.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3888 9085 3888 9083 3887 9082 3888 9081
3865 9071 3856 9101 3860 9104 3861 9105
3861 9108 3860 9113 3862 9123 3865 9123
3868 9127
TIME...MOT...LOC 2143Z 243DEG 44KT 3869 9096
HAIL...1.00IN
WIND...60MPH
$$
BRCThe office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 27, 4:23 PM CDT | Severe Thunderstorm Warning | LSX | Lincoln, Pike | 52 min |
| Mar 27, 4:52 PM CDT | Severe Thunderstorm Warning | LSX | Saint Charles, Saint Louis | 38 min |
| Mar 27, 5:24 PM CDT | Severe Thunderstorm Warning | LSX | Franklin, Gasconade | 15 min |
| Mar 27, 5:26 PM CDT | Severe Thunderstorm Warning | LSX | Saint Charles, Saint Louis, City of Saint Louis | 38 min |
| Mar 27, 5:36 PM CDT | Severe Thunderstorm Warning | LSX | Crawford, Washington | 28 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.