Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 96, NWS St. Louis, MO

April 25, 2012Pike County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 25, 2012, 9:50 PM CDT for Pike County, Illinois. It was in force for 40 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
Apr 25, 2012, 9:50 PM CDT (02:50 UTC)
Expired
Apr 25, 2012, 10:30 PM CDT
In force
40 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.75 in
Wind
50.0 mph

County Pike County, IL

The radar

The St Louis radar (KLSX), 110 km from the middle of the area, began a volume at 02:50 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.

IssuedProductOfficeLasted
Apr 25, 7:47 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 2.8 hours before the alert went out and 182 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-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2012-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1745 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2012-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 261 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1745 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
1353 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
261 m²/s²
0-3 km storm-relative helicity
449 m²/s²
Significant tornado parameter
1.2
Supercell composite
4.2

Open this sounding in Storm Lab

The text

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

084 
WUUS53 KLSX 260250
SVRLSX
ILC149-260330-
/O.NEW.KLSX.SV.W.0096.120426T0250Z-120426T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
950 PM CDT WED APR 25 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL PIKE COUNTY IN WEST CENTRAL ILLINOIS...

* UNTIL 1030 PM CDT

* AT 945 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 5 MILES SOUTHWEST
  OF BUCKHORN...AND MOVING SOUTHEAST AT 30 MPH.

  HAZARD...GOLF BALL SIZE HAIL.

  SOURCE...TRAINED WEATHER SPOTTERS.

  IMPACT...DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

* LOCATIONS IMPACTED INCLUDE...
  GRIGGSVILLE...VALLEY CITY AND FLORENCE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DEADLY CLOUD TO GROUND
LIGHTNING. SEEK SHELTER INSIDE A WELL-BUILT STRUCTURE. STAY AWAY FROM
WINDOWS.

&&

LAT...LON 3975 9061 3972 9064 3969 9064 3963 9060
      3961 9060 3959 9058 3958 9059 3976 9092
      3976 9061
TIME...MOT...LOC 0250Z 301DEG 26KT 3984 9083

HAIL...1.75IN
WIND...<50 MPH

$$

CVKING

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 8:21 PM CDTSevere Thunderstorm WarningLSXAdams54 min
Apr 25, 9:13 PM CDTSevere Thunderstorm WarningLSXAdams, Brown, Pike62 min
Apr 25, 10:21 PM CDTSevere Thunderstorm WarningLSXGreene, Pike39 min
Apr 25, 10:53 PM CDTSevere Thunderstorm WarningLSXGreene, Jersey, Macoupin67 min
Apr 25, 11:38 PM CDTSevere Thunderstorm WarningLSXFayette37 min
Apr 25, 11:44 PM CDTSevere Thunderstorm WarningLSXBond, Madison, Montgomery46 min
Apr 25, 11:55 PM CDTSevere Thunderstorm WarningLSXMadison50 min
Apr 26, 12:18 AM CDTSevere Thunderstorm WarningLSXClinton, Madison42 min
Apr 26, 12:45 AM CDTSevere Thunderstorm WarningLSXWashington45 min
Apr 26, 2:06 AM CDTSevere Thunderstorm WarningLSXFayette, Marion28 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2012Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.