Alert archive / Missouri / Tornado Warnings in 2012

Tornado Warning 28, NWS St. Louis, MO

October 17, 2012Saint Charles County, Missouri

NWS St. Louis, MO issued this tornado warning at Oct 17, 2012, 5:06 PM CDT for Saint Charles County, Missouri. It was in force for 24 min. 1 report 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: Oct 17, 2012, 5:06 PM CDT (22:06 UTC)
Expired: Oct 17, 2012, 5:30 PM CDT
In force: 24 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Saint Charles County, MO

The radar

The St Louis radar (KLSX), 17 km from the middle of the area, began a volume at 22:06 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
Oct 17, 5:21 PM CDT	TSTM WND GST 45	5 N St. Charles, MO	WINDS OF 40-45 MPH WITH SQUALL LINE.

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
Oct 17, 1:58 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.1 hours before the alert went out and 224 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1209 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 158 m²/s²
0-3 km storm-relative helicity: 269 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.

967 
WFUS53 KLSX 172206
TORLSX
MOC183-172230-
/O.NEW.KLSX.TO.W.0028.121017T2206Z-121017T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
506 PM CDT WED OCT 17 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL ST. CHARLES COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 530 PM CDT

* AT 502 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED NEAR DARDENNE PRAIRIE...AND MOVING NORTHEAST AT
  45 MPH.

  HAZARD...DEVELOPING TORNADO.

  SOURCE...RADAR INDICATED ROTATION.

  IMPACT...SIGNIFICANT HOUSE AND BUILDING DAMAGE POSSIBLE. MOBILE
           HOMES COMPLETELY DESTROYED IF HIT. SOME TREES UPROOTED OR
           SNAPPED. VEHICLES WILL LIKELY BE THROWN BY TORNADIC WINDS.

* LOCATIONS IMPACTED INCLUDE...
  COTTLEVILLE...ST. PETERS...ST. CHARLES AND KAMPVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3879 9048 3870 9074 3881 9080 3887 9058
      3887 9055 3888 9053 3889 9050 3882 9045
TIME...MOT...LOC 2206Z 242DEG 40KT 3877 9069

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

KANOFSKY

1 follow-up statement

865 
WWUS53 KLSX 172226
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
526 PM CDT WED OCT 17 2012

MOC183-172236-
/O.EXP.KLSX.TO.W.0028.000000T0000Z-121017T2230Z/
ST. CHARLES MO-
526 PM CDT WED OCT 17 2012

...THE TORNADO WARNING FOR CENTRAL ST. CHARLES COUNTY WILL EXPIRE AT
530 PM CDT...

THE STORM WHICH PROMPTED THE WARNING NO LONGER LOOKS CAPABLE OF 
PRODUCING A TORNADO. HOWEVER GUSTY WINDS ARE STILL POSSIBLE WITH 
THIS THUNDERSTORM AND A SEVERE THUNDERSTORM WARNING REMAINS IN 
EFFECT.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 8 PM CDT.

LAT...LON 3879 9048 3870 9074 3881 9080 3887 9058
      3887 9055 3888 9053 3889 9050 3882 9045
TIME...MOT...LOC 2226Z 242DEG 40KT 3887 9044

$$

KANOFSKY

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 17, 4:03 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Gasconade, Montgomery, Osage, Warren	42 min
Oct 17, 4:24 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Saint Charles, Warren, Washington	51 min
Oct 17, 4:54 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Jefferson, Lincoln, Saint Charles, Saint Louis and 1 more	51 min
Oct 17, 4:58 PM CDT	Tornado Warning	LSX	Lincoln, Saint Charles	32 min
Oct 17, 5:23 PM CDT	Severe Thunderstorm Warning	LSX	Jefferson, Saint Charles, Sainte Genevieve, Saint Francois, Saint Louis, City of Saint Louis	52 min

Nearby

Tornado Warnings in Missouri, 2012 Every tornado warning in 2012 Tornadoes 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.