Alert archive / Illinois / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 21, NWS St. Louis, MO

May 6, 2018Madison County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 6, 2018, 6:41 PM CDT for Madison County, Illinois. It was in force for 37 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 6, 2018, 6:41 PM CDT (23:41 UTC)
Expired
May 6, 2018, 7:18 PM CDT
In force
37 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Madison County, IL

The radar

The St Louis radar (KLSX), 87 km from the middle of the area, began a volume at 23:42 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 6, 7:05 PM CDTHAIL 0.751 Nne Alhambra, 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, 11.7 hours before the alert went out and 172 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 2018-05-06Temperature 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 2018-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.1939Sfc1 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
2694 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
-4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

214 
WUUS53 KLSX 062341
SVRLSX
ILC119-070030-
/O.NEW.KLSX.SV.W.0021.180506T2341Z-180507T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
641 PM CDT SUN MAY 6 2018

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Eastern Madison County in southwestern Illinois...

* Until 730 PM CDT.

* At 641 PM CDT, a severe thunderstorm was located over Livingston,
  moving south at 15 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...
  Highland, St. Jacob, Marine, Livingston, Alhambra, Pierron,
  Grantfork, Williamson and Kaufman.

This includes the following highways...
 Interstate 70 in Illinois between exits 21 and 30.
 Interstate 55 in Illinois between exits 33 and 37.

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.

&&

LAT...LON 3870 8985 3899 8982 3900 8977 3900 8970
      3891 8964 3888 8964 3887 8961 3886 8960
      3875 8960
TIME...MOT...LOC 2341Z 346DEG 11KT 3897 8976 

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

Gosselin
2 follow-up statements
001 
WWUS53 KLSX 070013
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
713 PM CDT SUN MAY 6 2018

ILC119-070030-
/O.CON.KLSX.SV.W.0021.000000T0000Z-180507T0030Z/
Madison IL-
713 PM CDT SUN MAY 6 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR SOUTHEASTERN MADISON COUNTY IN SOUTHWESTERN ILLINOIS...

At 713 PM CDT, a severe thunderstorm was located near Highland,
moving southeast at 20 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...
Highland, St. Jacob, Marine, Pierron and Grantfork. 

This includes Interstate 70 in Illinois between exits 21 and 30.
 
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.

&&

LAT...LON 3870 8985 3885 8983 3886 8974 3887 8967
      3888 8964 3887 8961 3886 8960 3875 8960
TIME...MOT...LOC 0013Z 337DEG 19KT 3882 8968 

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

Gosselin
012 
WWUS53 KLSX 070018
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
718 PM CDT SUN MAY 6 2018

ILC119-070028-
/O.CAN.KLSX.SV.W.0021.000000T0000Z-180507T0030Z/
Madison IL-
718 PM CDT SUN MAY 6 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MADISON COUNTY IN
SOUTHWESTERN ILLINOIS IS CANCELLED...
                
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 has been cancelled.

LAT...LON 3870 8985 3885 8983 3886 8974 3887 8967
      3888 8964 3887 8961 3886 8960 3875 8960
TIME...MOT...LOC 0015Z 346DEG 11KT 3880 8967 

$$

Gosselin

The office that day

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

IssuedProductOfficeCountiesLasted
May 6, 11:37 AM CDTRiver Flood WarningLSXJersey20 days
May 6, 5:26 PM CDTSpecial Weather StatementLSXMontgomery49 min
May 6, 5:34 PM CDTSpecial Weather StatementLSXMontgomery41 min
May 6, 5:59 PM CDTSpecial Weather StatementLSXMontgomery46 min
May 6, 6:38 PM CDTSpecial Weather StatementLSXMadison52 min
May 6, 6:53 PM CDTSpecial Weather StatementLSXBrown52 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.