Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 21, NWS St. Louis, MO

March 27, 20214 counties in Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Mar 27, 2021, 8:21 PM CDT for 4 counties in Illinois. It was in force for 39 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
Mar 27, 2021, 8:21 PM CDT (01:21 UTC)
Expired
Mar 27, 2021, 9:00 PM CDT
In force
39 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Clinton County, IL, Fayette County, IL, Marion County, IL, Washington County, IL

The radar

The Evansville,IN radar (KVWX), 122 km from the middle of the area, began a volume at 01:22 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.

What was reported inside it

TimeReportWhereRemark
Mar 27, 8:29 PM CDTHAIL 0.751 Ne Irvington, ILREPORT FROM MPING: DIME (0.75 IN.).

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
Mar 27, 4:44 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.4 hours before the alert went out and 166 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 00:00Z on 2021-03-28Temperature 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 00:00Z on 2021-03-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 square meters per square second.1939587897117136Sfc1 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
933 m above ground
0-6 km bulk shear
86 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
202 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

739 
WUUS53 KLSX 280121
SVRLSX
ILC027-051-121-189-280200-
/O.NEW.KLSX.SV.W.0021.210328T0121Z-210328T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
821 PM CDT Sat Mar 27 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Northeastern Clinton County in south central Illinois...
  Marion County in south central Illinois...
  Central Fayette County in south central Illinois...
  Northeastern Washington County in south central Illinois...

* Until 900 PM CDT.

* At 818 PM CDT, severe thunderstorms were located along a line
  extending from near Altamont to 6 miles southwest of Kinmundy to
  near Ashley, moving east at 50 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Centralia, Salem, Nashville, St. Elmo, Sandoval, Wamac, Central
  City, Odin, Kinmundy, Brownstown, Irvington, Patoka, Farina, Omega,
  Stephen Forbes Station, Shobonier, Fairman, Wrights Corner, Shattuc
  and Helm.

This includes the following highways...
 Interstate 70 in Illinois between exits 68 and 76.
 Interstate 57 in Illinois between exits 109 and 135.
 Interstate 64 in Illinois between exits 50 and 61.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3847 8914 3835 8915 3833 8945 3869 8917
      3911 8904 3917 8881 3891 8881 3891 8869
      3848 8870
TIME...MOT...LOC 0118Z 256DEG 44KT 3909 8881 3873 8895 3830 8924 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

BRC
1 follow-up statement
643 
WWUS53 KLSX 280141
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
841 PM CDT Sat Mar 27 2021

ILC027-051-121-189-280200-
/O.CON.KLSX.SV.W.0021.000000T0000Z-210328T0200Z/
Clinton IL-Marion IL-Fayette IL-Washington IL-
841 PM CDT Sat Mar 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM CDT
FOR EAST CENTRAL CLINTON...MARION...SOUTHEASTERN FAYETTE AND
NORTHEASTERN WASHINGTON COUNTIES...

At 840 PM CDT, severe thunderstorms were located along a line
extending from Teutopolis to near Iola to near Mount Vernon, moving
east 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...
Centralia, Salem, Nashville, Wamac, Central City, Odin, Kinmundy,
Irvington, Farina, Omega, Stephen Forbes Station, Helm, Tonti, La
Clede, Beaucoup, Hoyleton, Iuka, Junction City, St. Peter and Alma.

This includes the following highways...
 Interstate 57 in Illinois between exits 109 and 135.
 Interstate 64 in Illinois between exits 50 and 61.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3833 8945 3847 8934 3862 8906 3884 8887
      3891 8881 3891 8869 3848 8870 3847 8914
      3835 8915
TIME...MOT...LOC 0140Z 256DEG 44KT 3915 8850 3879 8864 3836 8893 

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

BRC

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 27, 7:03 PM CDTTornado WarningLSXBond, Clinton, Madison, Saint Clair42 min
Mar 27, 7:06 PM CDTSevere Thunderstorm WarningLSXClinton, Monroe, Saint Clair, Washington39 min
Mar 27, 7:13 PM CDTTornado WarningLSXClinton, Saint Clair, Washington47 min
Mar 27, 7:27 PM CDTSevere Thunderstorm WarningLSXMonroe, Randolph, Saint Clair, Washington48 min
Mar 27, 7:43 PM CDTSevere Thunderstorm WarningLSXBond, Clinton, Fayette, Madison, Marion, Saint Clair and 1 more47 min
Mar 27, 7:45 PM CDTTornado WarningLSXBond, Clinton, Fayette, Marion45 min
Mar 27, 7:59 PM CDTTornado WarningLSXClinton, Marion, Washington31 min
Mar 27, 8:11 PM CDTSevere Thunderstorm WarningLSXRandolph, Saint Clair, Washington64 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.