Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 17, NWS St. Louis, MO

January 17, 2012Randolph County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jan 17, 2012, 6:35 AM CST for Randolph County, Illinois. It was in force for 25 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: Jan 17, 2012, 6:35 AM CST (12:35 UTC)
Expired: Jan 17, 2012, 7:00 AM CST
In force: 25 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Randolph County, IL

The radar

The St Louis radar (KLSX), 121 km from the middle of the area, began a volume at 12:36 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
Jan 16, 11:47 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 0.6 hours before the alert went out and 270 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: 557 m above ground
0-6 km bulk shear: 87 kt
0-1 km storm-relative helicity: -88 m²/s²
0-3 km storm-relative helicity: -55 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.

659 
WUUS53 KLSX 171235
SVRLSX
ILC157-171300-
/O.NEW.KLSX.SV.W.0017.120117T1235Z-120117T1300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
635 AM CST TUE JAN 17 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN RANDOLPH COUNTY IN SOUTHWEST ILLINOIS...

* UNTIL 700 AM CST

* AT 633 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM BREMEN TO ST. MARY...AND MOVING
  EAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  CHESTER...BREMEN...STEELEVILLE...PERCY...WELGE AND ROCKWOOD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH 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 3781 8967 3781 8970 3784 8974 3785 8979
      3788 8980 3790 8984 3790 8985 3787 8990
      3787 8991 3804 8970 3804 8959 3795 8959
TIME...MOT...LOC 1235Z 265DEG 39KT 3801 8980 3789 8994
WIND...HAIL 60MPH 1.00IN

$$

TRUETT

2 follow-up statements

879 
WWUS53 KLSX 171250
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
650 AM CST TUE JAN 17 2012

ILC157-171300-
/O.CON.KLSX.SV.W.0017.000000T0000Z-120117T1300Z/
RANDOLPH IL-
650 AM CST TUE JAN 17 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
RANDOLPH COUNTY UNTIL 700 AM CST...

AT 649 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM PERCY TO CHESTER...MOVING EAST AT
45 MPH.

LOCATIONS IMPACTED INCLUDE...
  ROCKWOOD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH 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 3781 8967 3781 8970 3784 8974 3785 8979
      3788 8980 3790 8984 3790 8985 3787 8990
      3787 8991 3804 8970 3804 8959 3795 8959
TIME...MOT...LOC 1250Z 265DEG 39KT 3802 8959 3790 8973
WIND...HAIL 60MPH 1.00IN

$$

TRUETT

786 
WWUS53 KLSX 171301
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
701 AM CST TUE JAN 17 2012

ILC157-171310-
/O.EXP.KLSX.SV.W.0017.000000T0000Z-120117T1300Z/
RANDOLPH IL-
701 AM CST TUE JAN 17 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN RANDOLPH COUNTY
HAS EXPIRED...

AT 7 AM...THE LINE OF STORMS WHICH PROMPTED THE WARNING WAS ALONG 
RANDOLPH....JACKSON COUNTY LINE...AND WAS WEAKENING AS IT MOVED EAST 
AT 45 MPH.

LAT...LON 3781 8967 3781 8970 3784 8974 3785 8979
      3788 8980 3790 8984 3790 8985 3787 8990
      3787 8991 3804 8970 3804 8959 3795 8959
TIME...MOT...LOC 1300Z 265DEG 39KT 3803 8945 3791 8959

$$

TRUETT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jan 16, 11:59 PM CST	Severe Thunderstorm Warning	LSX	Macoupin, Montgomery	58 days
Jan 17, 1:23 AM CST	Severe Thunderstorm Warning	LSX	Calhoun	37 min
Jan 17, 2:08 AM CST	Severe Thunderstorm Warning	LSX	Madison, Saint Clair	37 min
Jan 17, 2:17 AM CST	Severe Thunderstorm Warning	LSX	Madison	28 min
Jan 17, 2:35 AM CST	Tornado Warning	LSX	Monroe	40 min
Jan 17, 2:38 AM CST	Severe Thunderstorm Warning	LSX	Clinton, Madison, Saint Clair	52 min
Jan 17, 2:39 AM CST	Severe Thunderstorm Warning	LSX	Bond	36 min
Jan 17, 3:07 AM CST	Tornado Warning	LSX	Clinton, Monroe, Saint Clair, Washington	38 min
Jan 17, 3:23 AM CST	Severe Thunderstorm Warning	LSX	Clinton, Marion	35 min
Jan 17, 3:46 AM CST	Tornado Warning	LSX	Clinton, Washington	29 min
Jan 17, 4:34 AM CST	Areal Flood Advisory	LSX	Bond, Clinton, Fayette, Macoupin, Madison, Marion and 4 more	60 days
Jan 17, 5:14 AM CST	Severe Thunderstorm Warning	LSX	Bond, Clinton, Madison, Saint Clair	46 min
Jan 17, 5:22 AM CST	Severe Thunderstorm Warning	LSX	Monroe, Randolph	38 min
Jan 17, 5:47 AM CST	Severe Thunderstorm Warning	LSX	Clinton, Fayette, Marion	43 min
Jan 17, 5:53 AM CST	Severe Thunderstorm Warning	LSX	Monroe, Randolph, Saint Clair, Washington	52 min
Jan 17, 6:01 AM CST	Severe Thunderstorm Warning	LSX	Randolph	44 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.