Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 17, NWS St. Louis, MO

March 27, 20214 counties in Illinois; Sainte Genevieve County, Saint Francois County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Mar 27, 2021, 7:27 PM CDT for 4 counties in Illinois; Sainte Genevieve County, Saint Francois County, Missouri. It was in force for 48 min. 3 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, 7:27 PM CDT (00:27 UTC)
Expired
Mar 27, 2021, 8:15 PM CDT
In force
48 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, Washington County, IL, Saint Francois County, MO, Sainte Genevieve County, MO

The radar

The St Louis radar (KLSX), 86 km from the middle of the area, began a volume at 00:28 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, 7:46 PM CDTTSTM WND DMG2 S Farmington, MOTREE LIMBS REPORTED DOWN VIA PUBLIC REPORT.
Mar 27, 8:15 PM CDTHAIL 0.752 E Coffman, MOCORRECTS PREVIOUS HAIL REPORT FROM 2 E COFFMAN. REPORT VIA FACEBOOK.
Mar 27, 8:15 PM CDTHAIL 13 Ssw River Aux Vases, MO

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, 0.5 hours before the alert went out and 281 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.

257 
WUUS53 KLSX 280027
SVRLSX
ILC133-157-163-189-MOC186-187-280115-
/O.NEW.KLSX.SV.W.0017.210328T0027Z-210328T0115Z/

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

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southeastern Monroe County in southwestern Illinois...
  Southwestern Washington County in south central Illinois...
  Randolph County in southwestern Illinois...
  Southeastern St. Clair County in southwestern Illinois...
  Ste. Genevieve County in southeastern Missouri...
  St. Francois County in southeastern Missouri...

* Until 815 PM CDT.

* At 727 PM CDT, severe thunderstorms were located along a line
  extending from near Smithton to near Pilot Knob, moving east at 35
  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...
  Farmington, Desloge, Ste. Genevieve, Sparta, Red Bud, Bismarck,
  Park Hills, New Athens, Marissa, Tilden, Iron Mountain Lake,
  Evansville, Lively Grove, Bloomsdale, Baldwin, St. Mary,
  Weingarten, Womac, Rocky Ridge and Knob Lick.

This includes Interstate 55 in Missouri between exits 141 and 162.
 
This also includes St. Joe State Park, Hawn State Park, Felix Valle
House State Park, and Missouri Mines Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3772 9065 3810 9033 3809 9029 3812 9025
      3816 9027 3831 9014 3834 8950 3765 9014
      3765 9064
TIME...MOT...LOC 0027Z 263DEG 32KT 3834 9002 3762 9071 

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

CVKING
3 follow-up statements
703 
WWUS53 KLSX 280038
SVSLSX

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

ILC133-157-163-189-MOC186-187-280115-
/O.CON.KLSX.SV.W.0017.000000T0000Z-210328T0115Z/
Monroe IL-Washington IL-Randolph IL-St. Clair IL-Ste. Genevieve MO-
St. Francois MO-
738 PM CDT Sat Mar 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHEASTERN MONROE...SOUTHWESTERN WASHINGTON...RANDOLPH...
SOUTHEASTERN ST. CLAIR...STE. GENEVIEVE AND SOUTHEASTERN ST. FRANCOIS
COUNTIES...

At 738 PM CDT, severe thunderstorms were located along a line
extending from near New Athens to near Pilot Knob, moving east at 35
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...
Farmington, Ste. Genevieve, Sparta, Red Bud, Park Hills, New Athens,
Marissa, Tilden, Iron Mountain Lake, Evansville, Lively Grove,
Bloomsdale, Baldwin, St. Mary, Knob Lick, Weingarten, Womac, Rocky
Ridge, Coffman and Iron Mountain.

This also includes St. Joe State Park, Hawn State Park, Felix Valle
House State Park, and Missouri Mines Historic Site.
 
This includes Interstate 55 in Missouri between exits 141 and 162.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3834 8950 3765 9014 3765 9064 3772 9064
      3809 9028 3832 8999
TIME...MOT...LOC 0038Z 263DEG 32KT 3835 8991 3763 9060 

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

CVKING
418 
WWUS53 KLSX 280051
SVSLSX

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

ILC133-157-163-189-MOC186-187-280115-
/O.CON.KLSX.SV.W.0017.000000T0000Z-210328T0115Z/
Monroe IL-Washington IL-Randolph IL-St. Clair IL-Ste. Genevieve MO-
St. Francois MO-
751 PM CDT Sat Mar 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHEASTERN MONROE...SOUTHWESTERN WASHINGTON...RANDOLPH...
SOUTHEASTERN ST. CLAIR...STE. GENEVIEVE AND SOUTHERN ST. FRANCOIS
COUNTIES...

At 750 PM CDT, severe thunderstorms were located along a line
extending from near Marissa to near Iron Mountain Lake, moving east
at 30 mph.

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

SOURCE...Trained weather spotters reported tree limbs down in 
         Farmington.

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

Locations impacted include...
Farmington, Ste. Genevieve, Sparta, Red Bud, Park Hills, New Athens,
Marissa, Tilden, Iron Mountain Lake, Evansville, Lively Grove,
Bloomsdale, Baldwin, St. Mary, Knob Lick, Weingarten, Womac, Rocky
Ridge, Coffman and Preston.

This also includes Hawn State Park and Felix Valle House State Park.
 
This includes Interstate 55 in Missouri between exits 141 and 157.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3834 8950 3765 9014 3765 9064 3832 8999
TIME...MOT...LOC 0050Z 265DEG 28KT 3830 8979 3768 9052 

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

CVKING
641 
WWUS53 KLSX 280107
SVSLSX

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

ILC133-280116-
/O.CAN.KLSX.SV.W.0017.000000T0000Z-210328T0115Z/
Monroe IL-
807 PM CDT Sat Mar 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONROE COUNTY IS
CANCELLED...

The storms which prompted the warning have 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...and southeastern Missouri.

LAT...LON 3834 8950 3765 9014 3765 9064 3833 8969
TIME...MOT...LOC 0106Z 263DEG 32KT 3832 8961 3770 9034 

$$

ILC157-163-189-MOC186-187-280115-
/O.CON.KLSX.SV.W.0017.000000T0000Z-210328T0115Z/
Washington IL-Randolph IL-St. Clair IL-Ste. Genevieve MO-
St. Francois MO-
807 PM CDT Sat Mar 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHWESTERN WASHINGTON...RANDOLPH...SOUTHEASTERN ST. CLAIR...
STE. GENEVIEVE AND SOUTHERN ST. FRANCOIS COUNTIES...

At 806 PM CDT, severe thunderstorms were located along a line
extending from Lively Grove to near Knob Lick, moving east at 35 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...
Farmington, Ste. Genevieve, Sparta, Marissa, Tilden, Evansville,
Lively Grove, Baldwin, St. Mary, Knob Lick, Weingarten, Womac, Rocky
Ridge, Coffman, Preston, Ellis Grove, Houston, Kaskaskia, Roots and
Modoc.

This also includes Hawn State Park and Felix Valle House State Park.
 
This includes Interstate 55 in Missouri between exits 141 and 150.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3834 8950 3765 9014 3765 9064 3833 8969
TIME...MOT...LOC 0106Z 263DEG 32KT 3832 8961 3770 9034 

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

CVKING

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, 7:43 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
Mar 27, 7:53 PM CDTSevere Thunderstorm WarningLSXIron, Madison, Reynolds, Saint Francois67 min
Mar 27, 9:10 PM CDTAreal Flood AdvisoryLSXMadison3 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 2021Severe Thunderstorm Warnings in Missouri, 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.