Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 123, NWS Springfield, MO

August 17, 2021St. Clair County, Missouri

NWS Springfield, MO issued this severe thunderstorm warning at Aug 17, 2021, 4:28 PM CDT for St. Clair County, Missouri. It was in force for 47 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 17, 2021, 4:28 PM CDT (21:28 UTC)
Expired: Aug 17, 2021, 5:15 PM CDT
In force: 47 min
Issued by: NWS Springfield, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County St. Clair County, MO

The radar

The Springfield radar (KSGF), 86 km from the middle of the area, began a volume at 21:30 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 17, 4:47 PM CDT	TSTM WND DMG	5 Sw Vista, MO	SEVERE THUNDERSTORM WIND GUSTS DESTROYED A POWER POLE AND SEVERAL TREES ALONG HIGHWAY V IN RURAL ST. CLAIR COUNTY.
Aug 17, 5:02 PM CDT	TSTM WND DMG	2 Nw Vista, MO	SEVERE THUNDERSTORM WIND GUSTS DAMAGED SEVERAL TREES CREATING DAMAGE TO SOME POWERLINES SOUTH OF OSCEOLA ALONG HIGHWAY WW. THIS RESULTED IN POWER OUTAGES TO NUMEROUS HOMES, BUSINESSES, AND GOVERNMENT BUILDINGS IN THE AREA, INCLUDING THE SHERIFFS OFFICE.

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 12:00Z, 9.5 hours before the alert went out and 119 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 430 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 1276 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 34 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

710 
WUUS53 KSGF 172128
SVRSGF
MOC185-172215-
/O.NEW.KSGF.SV.W.0123.210817T2128Z-210817T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Springfield MO
428 PM CDT Tue Aug 17 2021

The National Weather Service in Springfield has issued a

* Severe Thunderstorm Warning for...
  Southeastern St. Clair County in west central Missouri...

* Until 515 PM CDT.

* At 428 PM CDT, a severe thunderstorm was located 8 miles south of
  Osceola, or 15 miles east of El Dorado Springs, moving northeast at
  10 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...
  Osceola...                        Roscoe...
  Vista...                          Gerster...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 3788 9374 3793 9386 3805 9376 3808 9361
      3798 9353
TIME...MOT...LOC 2128Z 219DEG 9KT 3794 9375 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Cramer

1 follow-up statement

351 
WWUS53 KSGF 172206
SVSSGF

Severe Weather Statement
National Weather Service Springfield MO
506 PM CDT Tue Aug 17 2021

MOC185-172216-
/O.EXP.KSGF.SV.W.0123.000000T0000Z-210817T2215Z/
St. Clair MO-
506 PM CDT Tue Aug 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ST. CLAIR COUNTY
WILL EXPIRE AT 515 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However heavy rain
is still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Springfield.

LAT...LON 3788 9374 3793 9386 3805 9376 3808 9361
      3798 9353
TIME...MOT...LOC 2206Z 219DEG 9KT 3801 9368 

$$

Cramer

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 3:21 PM CDT	Special Weather Statement	SGF	Benton	24 min
Aug 17, 3:37 PM CDT	Special Weather Statement	SGF	Morgan	23 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2021 Every 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.