Alert archive / Illinois / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 159, NWS St. Louis, MO
NWS St. Louis, MO issued this severe thunderstorm warning at May 20, 2012, 4:18 PM CDT for Greene County, Jersey County, Macoupin County, Illinois. It was in force for 27 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
- May 20, 2012, 4:18 PM CDT (21:18 UTC)
- Expired
- May 20, 2012, 4:45 PM CDT
- In force
- 27 min
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 50.0 mph
Counties Greene County, IL, Jersey County, IL, Macoupin County, IL
The radar
The St Louis radar (KLSX), 47 km from the middle of the area, began a volume at 21:20 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 |
|---|---|---|---|
| May 20, 4:41 PM CDT | HAIL 0.5 | Rockbridge, IL |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 9.3 hours before the alert went out and 197 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.
- Mixed-layer CAPE
- 616 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 1773 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- -67 m²/s²
- 0-3 km storm-relative helicity
- -55 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
335
WUUS53 KLSX 202118
SVRLSX
ILC061-083-117-202145-
/O.NEW.KLSX.SV.W.0159.120520T2118Z-120520T2145Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
418 PM CDT SUN MAY 20 2012
THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTH CENTRAL GREENE COUNTY IN SOUTHWEST ILLINOIS...
JERSEY COUNTY IN SOUTHWEST ILLINOIS...
SOUTHWESTERN MACOUPIN COUNTY IN SOUTHWEST ILLINOIS...
* UNTIL 445 PM CDT
* AT 416 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 5 MILES NORTH OF
GRAFTON...AND MOVING NORTHEAST AT 15 MPH.
HAZARD...QUARTER SIZE HAIL.
SOURCE...RADAR INDICATED.
IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.
* LOCATIONS IMPACTED INCLUDE...
JERSEYVILLE...OLD KANE...KEMPER...FIELDON...OTTERVILLE...
MCCLUSKY...KANE...DELHI...FIDELITY...PIASA AND MEDORA.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.
&&
LAT...LON 3910 9006 3896 9040 3897 9048 3896 9052
3902 9058 3903 9057 3905 9059 3909 9059
3933 9026
TIME...MOT...LOC 2118Z 234DEG 12KT 3905 9046
HAIL...1.00IN
WIND...<50 MPH
$$
GKS2 follow-up statements
271
WWUS53 KLSX 202133
SVSLSX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
433 PM CDT SUN MAY 20 2012
ILC061-083-117-202145-
/O.CON.KLSX.SV.W.0159.000000T0000Z-120520T2145Z/
JERSEY IL-MACOUPIN IL-GREENE IL-
433 PM CDT SUN MAY 20 2012
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL
GREENE...SOUTHWESTERN MACOUPIN AND JERSEY COUNTIES UNTIL 445 PM
CDT...
AT 428 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 6 MILES SOUTHWEST
OF JERSEYVILLE...AND MOVING NORTHEAST AT 15 MPH.
HAZARD...QUARTER SIZE HAIL.
SOURCE...RADAR INDICATED.
IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.
LOCATIONS IMPACTED INCLUDE...
JERSEYVILLE...OLD KANE...KEMPER...MCCLUSKY...KANE...DELHI...
FIDELITY...PIASA AND MEDORA.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.
TORRENTIAL RAINFALL IS OCCURRING WITH THIS STORM...AND MAY LEAD TO
FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS!
&&
LAT...LON 3910 9006 3896 9040 3897 9048 3896 9052
3902 9058 3903 9057 3905 9059 3909 9059
3933 9026
TIME...MOT...LOC 2133Z 234DEG 12KT 3908 9041
HAIL...1.00IN
WIND...<50 MPH
$$
GKS220
WWUS53 KLSX 202145
SVSLSX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
445 PM CDT SUN MAY 20 2012
ILC061-083-117-202155-
/O.EXP.KLSX.SV.W.0159.000000T0000Z-120520T2145Z/
JERSEY IL-MACOUPIN IL-GREENE IL-
445 PM CDT SUN MAY 20 2012
...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL GREENE...
SOUTHWESTERN MACOUPIN AND JERSEY COUNTIES HAS EXPIRED...
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
HOWEVER SMALL HAIL AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS
THUNDERSTORM.
LAT...LON 3910 9006 3896 9040 3897 9048 3896 9052
3902 9058 3903 9057 3905 9059 3909 9059
3933 9026
TIME...MOT...LOC 2133Z 234DEG 12KT 3908 9041
$$
GKSThe office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 5:06 PM CDT | Flash Flood Warning | LSX | Marion | 4 hr |
| May 20, 5:11 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Pike | 37 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.