Alert archive / Illinois / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 9, NWS St. Louis, MO

April 3, 2018Monroe County, Randolph County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 3, 2018, 3:21 PM CDT for Monroe County, Randolph County, Saint Clair County, Illinois. It was in force for 39 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 3, 2018, 3:21 PM CDT (20:21 UTC)
Expired
Apr 3, 2018, 4:00 PM CDT
In force
39 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

Counties Monroe County, IL, Randolph County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 83 km from the middle of the area, began a volume at 20:22 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 3, 1:33 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.4 hours before the alert went out and 238 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 12:00Z on 2018-04-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Lincoln, IL at 12:00Z on 2018-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 317 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
549 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
317 m²/s²
0-3 km storm-relative helicity
346 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

236 
WUUS53 KLSX 032021
SVRLSX
ILC133-157-163-032100-
/O.NEW.KLSX.SV.W.0009.180403T2021Z-180403T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
321 PM CDT TUE APR 3 2018

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southeastern Monroe County in southwestern Illinois...
  North central Randolph County in southwestern Illinois...
  Southeastern St. Clair County in southwestern Illinois...

* Until 400 PM CDT.

* At 321 PM CDT, a severe thunderstorm was located near New Design,
  moving northeast at 50 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Freeburg, Red Bud, New Athens, Marissa, Baldwin, New Design, St.
  Libory, Lenzburg, Hecker, Fayetteville and Burksville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in St Louis.

&&

A tornado watch remains in effect until 800 PM CDT for southwestern
Illinois.

LAT...LON 3819 8971 3816 9019 3826 9023 3851 8971
TIME...MOT...LOC 2021Z 244DEG 43KT 3823 9016 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

TES
3 follow-up statements
842 
WWUS53 KLSX 032034
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
334 PM CDT TUE APR 3 2018

ILC157-032044-
/O.CAN.KLSX.SV.W.0009.000000T0000Z-180403T2100Z/
Randolph IL-
334 PM CDT TUE APR 3 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL RANDOLPH COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A tornado watch remains in effect until 800 PM CDT for southwestern
Illinois.

LAT...LON 3822 8971 3822 8998 3823 9002 3834 9004
      3851 8971
TIME...MOT...LOC 2034Z 244DEG 50KT 3830 8996 

$$

ILC133-163-032100-
/O.CON.KLSX.SV.W.0009.000000T0000Z-180403T2100Z/
Monroe IL-St. Clair IL-
334 PM CDT TUE APR 3 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM CDT
FOR EAST CENTRAL MONROE AND SOUTHEASTERN ST. CLAIR COUNTIES...

At 334 PM CDT, a severe thunderstorm was located near New Athens,
moving northeast at 55 mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
Freeburg, New Athens, Marissa, St. Libory, Lenzburg, Hecker and
Fayetteville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

&&

A tornado watch remains in effect until 800 PM CDT for southwestern
Illinois.

LAT...LON 3822 8971 3822 8998 3823 9002 3834 9004
      3851 8971
TIME...MOT...LOC 2034Z 244DEG 50KT 3830 8996 

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

TES
625 
WWUS53 KLSX 032044
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
344 PM CDT TUE APR 3 2018

ILC133-032053-
/O.CAN.KLSX.SV.W.0009.000000T0000Z-180403T2100Z/
Monroe IL-
344 PM CDT TUE APR 3 2018

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MONROE COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A tornado watch remains in effect until 800 PM CDT for southwestern
Illinois.

LAT...LON 3822 8971 3822 8988 3838 8989 3851 8971
TIME...MOT...LOC 2043Z 244DEG 43KT 3835 8983 

$$

ILC163-032100-
/O.CON.KLSX.SV.W.0009.000000T0000Z-180403T2100Z/
St. Clair IL-
344 PM CDT TUE APR 3 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM CDT
FOR SOUTHEASTERN ST. CLAIR COUNTY...

At 343 PM CDT, a severe thunderstorm was located near New Athens,
moving northeast at 50 mph.

HAZARD...60 mph wind gusts and nickel size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
New Athens, Marissa, St. Libory, Lenzburg and Fayetteville. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

&&

A tornado watch remains in effect until 800 PM CDT for southwestern
Illinois.

LAT...LON 3822 8971 3822 8988 3838 8989 3851 8971
TIME...MOT...LOC 2043Z 244DEG 43KT 3835 8983 

HAIL...0.88IN
WIND...60MPH
 
$$

TES
720 
WWUS53 KLSX 032050
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
350 PM CDT TUE APR 3 2018

ILC163-032100-
/O.EXP.KLSX.SV.W.0009.000000T0000Z-180403T2100Z/
St. Clair IL-
350 PM CDT TUE APR 3 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ST. CLAIR COUNTY
WILL EXPIRE AT 400 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.  However gusty winds
are still possible with this thunderstorm.

A tornado watch remains in effect until 800 PM CDT for southwestern
Illinois.

LAT...LON 3822 8971 3822 8988 3838 8989 3851 8971
TIME...MOT...LOC 2050Z 244DEG 43KT 3838 8975 

$$

TES

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 2, 7:46 PM CDTSpecial Weather StatementLSXClinton, Marion44 min
Apr 2, 11:13 PM CDTSevere Thunderstorm WarningLSXMonroe, Saint Clair32 min
Apr 2, 11:55 PM CDTSpecial Weather StatementLSXClinton50 min
Apr 3, 12:38 AM CDTSpecial Weather StatementLSXMadison52 min
Apr 3, 8:23 AM CDTRiver Flood WarningLSXFayette6 days
Apr 3, 10:08 AM CDTFlash Flood WarningLSXFayette6 hr
Apr 3, 10:16 AM CDTSpecial Weather StatementLSXFayette14 min
Apr 3, 3:26 PM CDTSevere Thunderstorm WarningLSXRandolph49 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2018Every severe thunderstorm warning in 2018

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.