Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 27, NWS St. Louis, MO

April 7, 2021Adams County, Brown County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 7, 2021, 6:38 PM CDT for Adams County, Brown County, Illinois. It was in force for 17 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
Apr 7, 2021, 6:38 PM CDT (23:38 UTC)
Expired
Apr 7, 2021, 6:55 PM CDT
In force
17 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Adams County, IL, Brown County, IL

The radar

The Lincoln radar (KILX), 122 km from the middle of the area, began a volume at 23:39 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
Apr 7, 6:40 PM CDTTSTM WND DMGCamp Point, ILEM REPORTING CAMP POINT FIRE DEPARTMENT RESPONDING TO DOWNED TREES ON POWER LINES.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.6 hours before the alert went out and 177 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 12:00Z on 2021-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 12:00Z on 2021-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 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
7 J/kg
Mixed-layer CIN
-292 J/kg
Mixed-layer LCL
1268 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

790 
WUUS53 KLSX 072338
SVRLSX
ILC001-009-080015-
/O.NEW.KLSX.SV.W.0027.210407T2338Z-210408T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
638 PM CDT Wed Apr 7 2021

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 715 PM CDT.

* At 638 PM CDT, severe thunderstorms were located along a line
  extending from near Carthage to near Clayton to near Barry, moving
  northeast at 45 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Mount Sterling, Camp Point, Clayton, Golden, Buckhorn, Versailles,
  Loraine, Woodville, Coatsburg, Mound Station, Columbus, Ripley, La
  Prairie, Paloma, Kellerville, Coopertown and Chatton.

This also includes Siloam Springs State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4019 9091 4011 9091 4010 9070 4008 9070
      4008 9067 4005 9068 4002 9063 4003 9061
      4001 9062 4000 9060 3998 9061 3998 9055
      3990 9056 3988 9058 3988 9097 4000 9122
      4020 9129
TIME...MOT...LOC 2338Z 208DEG 38KT 4039 9120 4006 9101 3969 9099 

HAIL...0.75IN
WIND...60MPH
 
$$

MRM
2 follow-up statements
124 
WWUS53 KLSX 072350
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
650 PM CDT Wed Apr 7 2021

ILC001-009-080015-
/O.CON.KLSX.SV.W.0027.000000T0000Z-210408T0015Z/
Adams IL-Brown IL-
650 PM CDT Wed Apr 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM CDT
FOR NORTHEASTERN ADAMS AND BROWN COUNTIES...

At 650 PM CDT, severe thunderstorms were located along a line
extending from Burnside to near Augusta to near Beverly, moving
northeast at 50 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Mount Sterling, Camp Point, Clayton, Golden, Loraine, Woodville,
Mound Station, Ripley, La Prairie, Coopertown and Chatton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4019 9091 4011 9091 4010 9070 4008 9070
      4008 9067 4005 9068 4002 9063 4003 9061
      4001 9062 4000 9060 3998 9061 3998 9055
      3990 9056 3988 9058 3999 9101 4020 9129
TIME...MOT...LOC 2350Z 206DEG 44KT 4053 9111 4020 9092 3983 9090 

HAIL...0.75IN
WIND...60MPH
 
$$

MRM
581 
WWUS53 KLSX 072355
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
655 PM CDT Wed Apr 7 2021

ILC001-009-080005-
/O.CAN.KLSX.SV.W.0027.000000T0000Z-210408T0015Z/
Adams IL-Brown IL-
655 PM CDT Wed Apr 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ADAMS AND BROWN
COUNTIES IS CANCELLED...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning has
been cancelled.

LAT...LON 4019 9091 4011 9091 4010 9070 4008 9070
      4008 9067 4005 9068 4002 9063 4003 9061
      4001 9062 4000 9060 3998 9061 3998 9055
      3990 9056 3988 9058 3999 9101 4020 9129
TIME...MOT...LOC 2354Z 208DEG 38KT 4057 9108 4024 9089 3987 9087 

$$

MRM

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 7, 5:09 PM CDTSevere Thunderstorm WarningLSXPike19 min
Apr 7, 6:27 PM CDTSevere Thunderstorm WarningLSXMadison, Monroe, Saint Clair49 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2021Every severe thunderstorm warning in 2021

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.