Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 4, NWS St. Louis, MO

March 27, 20214 counties in Illinois

NWS St. Louis, MO issued this tornado warning at Mar 27, 2021, 7:03 PM CDT for 4 counties in Illinois. It was in force for 42 min. 11 reports 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, 7:03 PM CDT (00:03 UTC)
Expired
Mar 27, 2021, 7:45 PM CDT
In force
42 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Bond County, IL, Clinton County, IL, Madison County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 100 km from the middle of the area, began a volume at 00:05 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, 7:03 PM CDTTSTM WND DMGTroy, ILFENCE AND DECK DAMAGE TO A HOME.
Mar 27, 7:05 PM CDTTSTM WND DMG2 Ese Troy, ILDRYWALL RIPPED FROM A HOME, ROOF RIPPED ALL OFF A POLE BARN.
Mar 27, 7:08 PM CDTTSTM WND DMG3 W Saint Jacob, ILFENCE DAMAGE WITH OUTBUILDING DESTROYED.
Mar 27, 7:08 PM CDTTORNADO1 N Saint Jacob, ILNWS OFFICIAL STORM SURVEY FOUND AN EF-1 TORNADO OCCURRED ALONG AN INTERMITTENT PATH OF NEARLY 5 MILES FROM NORTH OF ST. JACOB EAST INTO HIGHLAND. THE MOST SIGNIFICANT DAMAGE OCCURRED JUST WEST OF HIGHLAND, WHERE A LARGE, WELL-BUILT SHED WAS DESTROYED WITH DEBR
Mar 27, 7:15 PM CDTTSTM WND DMGHighland, ILHEAVY DAMAGE TO SEVERAL BUILDINGS, MULTIPLE TREES UPROOTED.
Mar 27, 7:17 PM CDTTSTM WND DMG1 W Highland, ILREPORT FROM MPING: TREES UPROOTED OR SNAPPED; ROOF BLOWN OFF.
Mar 27, 7:17 PM CDTTSTM WND GST 621 Ene Highland, IL
Mar 27, 7:18 PM CDTTSTM WND DMGSaint Jacob, ILFLAG POLE SNAPPED IN HALF.
Mar 27, 7:20 PM CDTHAIL 0.751 S Marine, IL
Mar 27, 7:37 PM CDTTSTM WND DMG4 W Beaver Creek, ILTREES AND POWER LINES DOWN ALONG MILLERSBURG ROAD.
Mar 27, 7:54 PM CDTTSTM WND DMG2 Ssw Marine, ILDOWNED TREE BRANCHES AND OTHER DEBRIS, REPORTED VIA TWITTER.

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, 0.1 hours before the alert went out and 176 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.

022 
WFUS53 KLSX 280003
TORLSX
ILC005-027-119-163-280045-
/O.NEW.KLSX.TO.W.0004.210328T0003Z-210328T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service St Louis MO
703 PM CDT Sat Mar 27 2021

The National Weather Service in St Louis has issued a

* Tornado Warning for...
  Northwestern Clinton County in south central Illinois...
  Southern Bond County in south central Illinois...
  Southeastern Madison County in southwestern Illinois...
  Northeastern St. Clair County in southwestern Illinois...

* Until 745 PM CDT.
    
* At 703 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Troy, moving east at 45 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Highland around 720 PM CDT.
  St. Rose around 725 PM CDT.
  Pocahontas and Jamestown around 730 PM CDT.
  Beaver Creek around 740 PM CDT.
  Tamalco around 745 PM CDT.

Other locations impacted by this tornadic thunderstorm include Kuhn,
Smithboro, Pleasant Mound, Keyesport, Grantfork, Pierron, Dudleyville
and Stolletown.

This includes Interstate 70 in Illinois between exits 21 and 52.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3870 8926 3860 8992 3877 8997 3894 8926
TIME...MOT...LOC 0003Z 257DEG 37KT 3871 8984 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

BRC
1 follow-up statement
739 
WWUS53 KLSX 280023
SVSLSX

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

ILC163-280032-
/O.CAN.KLSX.TO.W.0004.000000T0000Z-210328T0045Z/
St. Clair IL-
723 PM CDT Sat Mar 27 2021

...THE TORNADO WARNING FOR NORTHEASTERN ST. CLAIR COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
south central and southwestern Illinois.

LAT...LON 3870 8926 3864 8969 3882 8975 3894 8926
TIME...MOT...LOC 0022Z 257DEG 37KT 3875 8959 

$$

ILC005-027-119-280045-
/O.CON.KLSX.TO.W.0004.000000T0000Z-210328T0045Z/
Clinton IL-Bond IL-Madison IL-
723 PM CDT Sat Mar 27 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR
NORTHWESTERN CLINTON...SOUTHERN BOND COUNTIES IN SOUTH CENTRAL
ILLINOIS AND SOUTHEASTERN MADISON COUNTIES IN SOUTHWESTERN
ILLINOIS...
    
At 722 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Highland, moving east at 45 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Pocahontas and Jamestown around 730 PM CDT.
  Beaver Creek around 735 PM CDT.
  Greenville around 740 PM CDT.
  Tamalco around 745 PM CDT.
  Mulberry Grove around 750 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Smithboro, Pleasant Mound, Keyesport, Grantfork, Pierron, Dudleyville
and Stolletown.

This includes Interstate 70 in Illinois between exits 30 and 52.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3870 8926 3864 8969 3882 8975 3894 8926
TIME...MOT...LOC 0022Z 257DEG 37KT 3875 8959 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

BRC

The office that day

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

IssuedProductOfficeCountiesLasted
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
Mar 27, 8:21 PM CDTSevere Thunderstorm WarningLSXClinton, Fayette, Marion, Washington39 min

Nearby

Tornado Warnings in Illinois, 2021Every tornado warning in 2021Tornadoes 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.