Alert archive / Missouri / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 228, NWS St. Louis, MO

August 4, 20124 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 4, 2012, 9:07 PM CDT for 4 counties in Missouri. It was in force for 23 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 4, 2012, 9:07 PM CDT (02:07 UTC)
Expired: Aug 4, 2012, 9:30 PM CDT
In force: 23 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Gasconade County, MO, Montgomery County, MO, Osage County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 81 km from the middle of the area, began a volume at 02:08 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
Aug 4, 9:10 PM CDT	TSTM WND GST 45	5 Se Linn, MO
Aug 4, 9:10 PM CDT	HAIL 0.5	1 W Mount Sterling, MO	HEAVY RAIN AND GUSTY WINDS...NO ESTIMATE ON SPEED.

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 4, 6:12 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 2.1 hours before the alert went out and 276 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: 1173 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 2913 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

190 
WUUS53 KLSX 050207
SVRLSX
MOC073-139-151-219-050230-
/O.NEW.KLSX.SV.W.0228.120805T0207Z-120805T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
907 PM CDT SAT AUG 4 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN GASCONADE COUNTY IN EAST CENTRAL MISSOURI...
  SOUTHERN MONTGOMERY COUNTY IN EAST CENTRAL MISSOURI...
  EASTERN OSAGE COUNTY IN CENTRAL MISSOURI...
  WEST CENTRAL WARREN COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 930 PM CDT

* AT 904 PM CDT...A LINE OF SEVERE THUNDERSTORMS WAS LOCATED ALONG A
  LINE EXTENDING FROM CHAMOIS TO 7 MILES SOUTHWEST OF MOUNT
  STERLING...AND MOVING EAST AT 30 MPH.

  HAZARD...QUARTER SIZE HAIL AND 60 MPH WIND GUSTS.

  SOURCE...RADAR INDICATED.

  IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS. MINOR TREE
           DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER BROKEN.

* LOCATIONS IMPACTED INCLUDE...
  HERMANN...MOUNT STERLING...BIG SPRING...DRAKE...MORRISON...
  AMERICUS...GASCONADE...RHINELAND...BAY...SWISS AND MCKITTRICK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

&&

LAT...LON 3871 9171 3870 9166 3871 9164 3880 9165
      3883 9163 3884 9137 3844 9137 3842 9180
TIME...MOT...LOC 0207Z 270DEG 27KT 3872 9169 3842 9170

HAIL...1.00IN
WIND...60 MPH

$$

TRUETT

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 8:30 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Gasconade, Montgomery, Osage	45 min
Aug 4, 8:47 PM CDT	Severe Thunderstorm Warning	LSX	Gasconade, Osage	43 min
Aug 4, 9:20 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Gasconade, Warren, Washington	40 min
Aug 4, 9:38 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Jefferson, Saint Charles, Saint Louis, Warren, Washington	67 min
Aug 4, 10:22 PM CDT	Severe Thunderstorm Warning	LSX	Jefferson, Saint Charles, Saint Louis, City of Saint Louis	38 min
Aug 4, 10:59 PM CDT	Severe Thunderstorm Warning	LSX	Jefferson, Sainte Genevieve	46 min
Aug 4, 11:46 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Saint Charles, Warren	33 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2012 Every severe thunderstorm warning in 2012

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.