Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 145, NWS St. Louis, MO

May 4, 2012Adams County, Brown County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 4, 2012, 4:03 AM CDT for Adams County, Brown County, Illinois. It was in force for 42 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
May 4, 2012, 4:03 AM CDT (09:03 UTC)
Expired
May 4, 2012, 4:45 AM CDT
In force
42 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Adams County, IL, Brown County, IL

The radar

The Lincoln radar (KILX), 120 km from the middle of the area, began a volume at 09:03 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

TimeReportWhereRemark
May 4, 4:21 AM CDTHAIL 0.7Mound Station, ILDURATION 2 TO 3 MINUTES
May 4, 4:31 AM CDTHAIL 0.25Mount Sterling, ILDURATION 1 MINUTE THUS FAR

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.

IssuedProductOfficeLasted
May 4, 12:53 AM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 9.1 hours before the alert went out and 175 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, Davenport, at 00:00Z on 2012-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1056 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2012-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
1056 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
1420 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.7

Open this sounding in Storm Lab

The text

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

393 
WUUS53 KLSX 040903
SVRLSX
ILC001-009-040945-
/O.NEW.KLSX.SV.W.0145.120504T0903Z-120504T0945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
403 AM CDT FRI MAY 4 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN ADAMS COUNTY IN WEST CENTRAL ILLINOIS...
  BROWN COUNTY IN WEST CENTRAL ILLINOIS...

* UNTIL 445 AM CDT

* AT 400 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR CAMP
  POINT...AND MOVING EAST AT 25 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...
  CLAYTON...BUCKHORN...MOUNT STERLING...LA PRAIRIE...KELLERVILLE...
  MOUND STATION...RIPLEY...COOPERTOWN AND LA GRANGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4019 9091 4011 9090 4011 9070 4008 9070
      4008 9067 4005 9067 4003 9065 4003 9060
      3999 9060 3999 9052 3997 9050 3993 9053
      3988 9109 4020 9112
TIME...MOT...LOC 0903Z 264DEG 23KT 4002 9100

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

$$

BYRD
2 follow-up statements
845 
WWUS53 KLSX 040925
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
425 AM CDT FRI MAY 4 2012

ILC001-040935-
/O.CAN.KLSX.SV.W.0145.000000T0000Z-120504T0945Z/
ADAMS IL-
425 AM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ADAMS COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 4011 9090 4011 9070 4008 9070 4008 9067
      4005 9067 4003 9065 4003 9060 3999 9060
      3999 9052 3997 9050 3993 9053 3990 9091
TIME...MOT...LOC 0925Z 283DEG 27KT 3996 9079

$$

ILC009-040945-
/O.CON.KLSX.SV.W.0145.000000T0000Z-120504T0945Z/
BROWN IL-
425 AM CDT FRI MAY 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR BROWN COUNTY
UNTIL 445 AM CDT...

AT 422 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR BUCKHORN...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...
MOUNT STERLING...RIPLEY...COOPERTOWN AND LA GRANGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4011 9090 4011 9070 4008 9070 4008 9067
      4005 9067 4003 9065 4003 9060 3999 9060
      3999 9052 3997 9050 3993 9053 3990 9091
TIME...MOT...LOC 0925Z 283DEG 27KT 3996 9079

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

$$

TES
781 
WWUS53 KLSX 040941
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
441 AM CDT FRI MAY 4 2012

ILC009-040951-
/O.EXP.KLSX.SV.W.0145.000000T0000Z-120504T0945Z/
BROWN IL-
441 AM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR BROWN COUNTY WILL EXPIRE AT
445 AM CDT...

THE STORM 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 SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 5 AM CDT.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN ST LOUIS.

LAT...LON 4011 9090 4011 9070 4008 9070 4008 9067
      4005 9067 4003 9065 4003 9060 3999 9060
      3999 9052 3997 9050 3993 9053 3990 9091
TIME...MOT...LOC 0941Z 283DEG 27KT 3993 9064

$$

TES

The office that day

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

IssuedProductOfficeCountiesLasted
May 4, 6:27 AM CDTSevere Thunderstorm WarningLSXMacoupin33 min
May 4, 11:11 AM CDTSevere Thunderstorm WarningLSXClinton, Saint Clair, Washington34 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.