Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 93, NWS St. Louis, MO

April 15, 2012Jersey County, Macoupin County, Madison County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 15, 2012, 8:01 PM CDT for Jersey County, Macoupin County, Madison County, Illinois. It was in force for 30 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: Apr 15, 2012, 8:01 PM CDT (01:01 UTC)
Expired: Apr 15, 2012, 8:31 PM CDT
In force: 30 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Jersey County, IL, Macoupin County, IL, Madison County, IL

The radar

The St Louis radar (KLSX), 80 km from the middle of the area, began a volume at 01:02 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
Apr 15, 8:05 PM CDT	TSTM WND DMG	2 E Jerseyville, IL	DISPATCH REPORTS THAT A TREE FELL DOWN IN JERSEYVILLE.

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
Apr 15, 4:42 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.0 hours before the alert went out and 162 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: 502 J/kg
Mixed-layer CIN: -103 J/kg
Mixed-layer LCL: 972 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 346 m²/s²
0-3 km storm-relative helicity: 388 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 5.6

Open this sounding in Storm Lab

The text

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

204 
WUUS53 KLSX 160101
SVRLSX
ILC083-117-119-160145-
/O.NEW.KLSX.SV.W.0093.120416T0101Z-120416T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
801 PM CDT SUN APR 15 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN JERSEY COUNTY IN SOUTHWEST ILLINOIS...
  MACOUPIN COUNTY IN SOUTHWEST ILLINOIS...
  NORTH CENTRAL MADISON COUNTY IN SOUTHWEST ILLINOIS...

* UNTIL 845 PM CDT

* AT 757 PM CDT...A LINE OF SEVERE THUNDERSTORMS WAS LOCATED ALONG A
  LINE EXTENDING FROM JERSEYVILLE TO WEST ALTON...AND MOVING
  NORTHEAST AT 60 MPH.

  HAZARD...60 MPH WIND GUSTS.

  SOURCE...RADAR INDICATED.

  IMPACT...MINOR TREE DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER
           BROKEN.

* LOCATIONS IMPACTED INCLUDE...
  BETHALTO...STAUNTON...CARLINVILLE...GILLESPIE...BRIGHTON...
  KEMPER...DORSEY...SHIPMAN...PRAIRIETOWN...WORDEN...BUNKER HILL...
  LIVINGSTON...WILSONVILLE...BENLD...MOUNT OLIVE...GIRARD...
  FIDELITY...PIASA...MILES STATION AND MEDORA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH ONE IS NOT
IMMEDIATELY LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE
TO A PLACE OF SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT
OR SMALL INTERIOR ROOM.

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

&&

LAT...LON 3895 8970 3889 9007 3913 9031 3951 8971
TIME...MOT...LOC 0100Z 230DEG 51KT 3914 9026 3892 9017

HAIL...<.75IN
WIND...60 MPH

$$

BRITT

2 follow-up statements

684 
WWUS53 KLSX 160122
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
822 PM CDT SUN APR 15 2012

ILC083-119-160130-
/O.CAN.KLSX.SV.W.0093.000000T0000Z-120416T0145Z/
JERSEY IL-MADISON IL-
822 PM CDT SUN APR 15 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL MADISON AND
NORTHEASTERN JERSEY COUNTIES IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE 
WARNED AREA.  

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT.

LAT...LON 3900 8980 3900 9014 3923 9015 3951 8971
      3901 8970
TIME...MOT...LOC 0120Z 226DEG 52KT 3931 8997 3907 8995

$$

ILC117-160145-
/O.CON.KLSX.SV.W.0093.000000T0000Z-120416T0145Z/
MACOUPIN IL-
822 PM CDT SUN APR 15 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR MACOUPIN
COUNTY UNTIL 845 PM CDT...

AT 819 PM CDT...A LINE OF SEVERE THUNDERSTORMS WAS LOCATED ALONG A
LINE EXTENDING FROM 6 MILES WEST OF CARLINVILLE TO BUNKER HILL...AND
MOVING NORTHEAST AT 60 MPH.

HAZARD...60 MPH WIND GUSTS.

SOURCE...RADAR INDICATED.

IMPACT...MINOR TREE DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER
         BROKEN.

LOCATIONS IMPACTED INCLUDE...
STAUNTON...CARLINVILLE...GILLESPIE...WILSONVILLE...BENLD...MOUNT
OLIVE...GIRARD...PRUETT...DORCHESTER...WHITE CITY...NILWOOD...
STANDARD CITY...HORNSBY AND ATWATER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH ONE IS NOT
IMMEDIATELY LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE
TO A PLACE OF SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT
OR SMALL INTERIOR ROOM.

&&

LAT...LON 3900 8980 3900 9014 3923 9015 3951 8971
      3901 8970
TIME...MOT...LOC 0120Z 226DEG 52KT 3931 8997 3907 8995

HAIL...<.75IN
WIND...60 MPH

$$

BRITT

097 
WWUS53 KLSX 160131 RRA
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
831 PM CDT SUN APR 15 2012

ILC117-160141-
/O.CAN.KLSX.SV.W.0093.000000T0000Z-120416T0145Z/
MACOUPIN IL-
831 PM CDT SUN APR 15 2012

...THE SEVERE THUNDERSTORM WARNING FOR MACOUPIN COUNTY IS
CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAS WEAKENED BELOW
SEVERE LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR
PROPERTY.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT.

LAT...LON 3900 8980 3900 9014 3923 9015 3951 8971
      3901 8970
TIME...MOT...LOC 0131Z 226DEG 52KT 3942 8982 3918 8980

$$

BRITT

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 15, 7:38 PM CDT	Severe Thunderstorm Warning	LSX	Jersey, Madison	32 min
Apr 15, 7:52 PM CDT	Severe Thunderstorm Warning	LSX	Monroe, Saint Clair	38 min

Nearby

Severe Thunderstorm Warnings in Illinois, 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.