Alert archive / Missouri / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 20, NWS St. Louis, MO

February 28, 2017Sainte Genevieve County, Saint Francois County, Missouri; Randolph County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Feb 28, 2017, 7:34 PM CST for Sainte Genevieve County, Saint Francois County, Missouri; Randolph County, Illinois. It was in force for 17 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Feb 28, 2017, 7:34 PM CST (01:34 UTC)
Expired: Feb 28, 2017, 7:51 PM CST
In force: 17 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Tornado: Possible
Hail: 1.0 in
Wind: 60.0 mph

Counties Randolph County, IL, Saint Francois County, MO, Sainte Genevieve County, MO

The radar

The St Louis radar (KLSX), 114 km from the middle of the area, began a volume at 01:36 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.

The watch it was issued in

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

Issued	Product	Office	Lasted
Feb 28, 2:19 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.6 hours before the alert went out and 290 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: 687 J/kg
Mixed-layer CIN: -73 J/kg
Mixed-layer LCL: 887 m above ground
0-6 km bulk shear: 72 kt
0-1 km storm-relative helicity: 395 m²/s²
0-3 km storm-relative helicity: 431 m²/s²
Significant tornado parameter: 1.6
Supercell composite: 6.7

Open this sounding in Storm Lab

The text

As transmitted.

223 
WUUS53 KLSX 010134
SVRLSX
ILC157-MOC186-187-010215-
/O.NEW.KLSX.SV.W.0020.170301T0134Z-170301T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
734 PM CST TUE FEB 28 2017

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  South central Randolph County in southwestern Illinois...
  Southeastern Ste. Genevieve County in southeastern Missouri...
  Southeastern St. Francois County in southeastern Missouri...

* Until 815 PM CST.

* At 734 PM CST, a severe thunderstorm was located near Womac, moving
  northeast at 45 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...
  Chester, St. Mary, Weingarten, Coffman, Womac, Kaskaskia, River Aux
  Vases and Minnith.

This includes Interstate 55 in Missouri between exits 141 and 143.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

A tornado watch remains in effect until 900 PM CST for southwestern
Illinois...and southeastern Missouri.

LAT...LON 3790 9022 3794 8986 3790 8985 3787 8990
      3787 8994 3783 8999 3767 9011 3764 9016
      3764 9021 3765 9021
TIME...MOT...LOC 0134Z 246DEG 37KT 3772 9022 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

Kanofsky

1 follow-up statement

982 
WWUS53 KLSX 010151
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
751 PM CST TUE FEB 28 2017

ILC157-MOC186-187-010201-
/O.CAN.KLSX.SV.W.0020.000000T0000Z-170301T0215Z/
Randolph IL-Ste. Genevieve MO-St. Francois MO-
751 PM CST TUE FEB 28 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL RANDOLPH...
SOUTHEASTERN STE. GENEVIEVE AND SOUTHEASTERN ST. FRANCOIS COUNTIES IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning has been cancelled.

A tornado watch remains in effect until 900 PM CST for southwestern
Illinois...and southeastern Missouri.

LAT...LON 3790 9022 3794 8986 3790 8985 3787 8990
      3787 8994 3783 8999 3767 9011 3764 9016
      3764 9021 3765 9021
TIME...MOT...LOC 0150Z 246DEG 37KT 3779 9002 

$$

Kanofsky

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 28, 6:14 PM CST	Tornado Warning	LSX	Reynolds	30 min
Feb 28, 6:16 PM CST	Severe Thunderstorm Warning	LSX	Iron, Reynolds	44 min
Feb 28, 6:56 PM CST	Tornado Warning	LSX	Iron, Madison, Reynolds, Saint Francois	34 min
Feb 28, 6:59 PM CST	Severe Thunderstorm Warning	LSX	Iron, Madison, Sainte Genevieve, Saint Francois	46 min
Feb 28, 7:30 PM CST	Tornado Warning	LSX	Madison, Sainte Genevieve, Saint Francois	19 min
Feb 28, 7:57 PM CST	Severe Thunderstorm Warning	LSX	Marion, Monroe, Shelby	48 min
Feb 28, 8:29 PM CST	Severe Thunderstorm Warning	LSX	Marion, Ralls	33 min
Feb 28, 8:37 PM CST	Tornado Warning	LSX	Marion, Ralls	27 min
Feb 28, 9:19 PM CST	Severe Thunderstorm Warning	LSX	Madison	17 min
Feb 28, 9:23 PM CST	Tornado Warning	LSX	Madison	11 min
Feb 28, 11:04 PM CST	Severe Thunderstorm Warning	LSX	Boone, Moniteau	41 min
Mar 1, 1:43 AM CST	Special Weather Statement	LSX	Crawford, Franklin, Washington	47 min
Mar 1, 1:56 AM CST	Special Weather Statement	LSX	Saint Louis, City of Saint Louis	34 min
Mar 1, 2:15 AM CST	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	34 min
Mar 1, 2:17 AM CST	Special Weather Statement	LSX	Iron, Sainte Genevieve, Saint Francois, Washington	43 min
Mar 1, 3:11 AM CST	Severe Thunderstorm Warning	LSX	Iron, Reynolds	36 min
Mar 1, 3:37 AM CST	Special Weather Statement	LSX	Madison	23 min
Feb 28, 6:14 PM CST	Severe Thunderstorm Warning	LSX	Monroe, Randolph, Saint Clair, Washington	46 min
Feb 28, 6:22 PM CST	Severe Thunderstorm Warning	LSX	Fayette	23 min
Feb 28, 6:57 PM CST	Severe Thunderstorm Warning	LSX	Clinton, Marion, Washington	48 min
Feb 28, 8:08 PM CST	Tornado Warning Tornado observed	LSX	Randolph	14 min
Feb 28, 9:07 PM CST	Severe Thunderstorm Warning	LSX	Adams, Brown, Pike	38 min
Feb 28, 9:23 PM CST	Tornado Warning	LSX	Brown, Pike	22 min
Mar 1, 2:39 AM CST	Severe Thunderstorm Warning	LSX	Clinton, Washington	25 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2017 Severe Thunderstorm Warnings in Illinois, 2017 Every severe thunderstorm warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.