Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 49, NWS St. Louis, MO

May 27, 20216 counties in Missouri; 6 counties in Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 27, 2021, 11:50 AM CDT for 6 counties in Missouri; 6 counties in Illinois. It was in force for 55 min. 6 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
May 27, 2021, 11:50 AM CDT (16:50 UTC)
Expired
May 27, 2021, 12:45 PM CDT
In force
55 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Calhoun County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Saint Clair County, IL, City of Saint Louis, MO, Franklin County, MO, Lincoln County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 31 km from the middle of the area, began a volume at 16:50 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 27, 12:00 PM CDTTSTM WND DMGO'Fallon, MOSEVERAL SMALL TREE BRANCHES DOWNED.
May 27, 12:04 PM CDTTSTM WND GST 501 Sse Lake Saint Louis, MOAT INTERSECTION OF I-64 AND HWY 364.
May 27, 12:23 PM CDTTSTM WND DMGGodfrey, IL2 INCH DIAMETER TREE LIMB BLOWN OFF.
May 27, 12:27 PM CDTTSTM WND DMG1 S Godfrey, ILNUMEROUS TREE LIMBS AND SEVERAL TREES BLOWN DOWN ON THE SOUTH SIDE OF GODFREY.
May 27, 12:30 PM CDTTSTM WND DMG4 N Wildwood, MOTREE BLOWN DOWN ONTO EATHERTON ROAD NEAR INTERSECTION WITH WILD HORSE CREEK ROAD.
May 27, 12:44 PM CDTTSTM WND DMG3 Se Miles Station, ILSEVERAL LARGE TREES BLOWN DOWN. ONE LARGE TREE FELL ONTO A POLE BARN CAUSING MODERATE DAMAGE. TREE ALSO KNOCKED GAS METER OFF OF THE HOUSE.

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
May 27, 11:26 AM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 4.8 hours before the alert went out and 210 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 2021-05-27Temperature 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 2021-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.19395878Sfc1 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
1679 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

806 
WUUS53 KLSX 271650
SVRLSX
ILC013-061-083-117-119-163-MOC071-113-183-189-219-510-271745-
/O.NEW.KLSX.SV.W.0049.210527T1650Z-210527T1745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
1150 AM CDT Thu May 27 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southeastern Calhoun County in southwestern Illinois...
  Southern Greene County in southwestern Illinois...
  Western Madison County in southwestern Illinois...
  Macoupin County in southwestern Illinois...
  Jersey County in southwestern Illinois...
  Northwestern St. Clair County in southwestern Illinois...
  St. Louis City in east central Missouri...
  St. Charles County in east central Missouri...
  Southeastern Lincoln County in east central Missouri...
  Northeastern Franklin County in east central Missouri...
  St. Louis County in east central Missouri...
  Southeastern Warren County in east central Missouri...

* Until 1245 PM CDT.

* At 1150 AM CDT, severe thunderstorms were located along a line
  extending from Greenfield to near Grafton to New Melle, moving east
  at 45 mph.

  HAZARD...70 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Severe thunderstorms will be near...
  Greenfield and Grafton around 1155 AM CDT.
  Jerseyville, St. Paul, Weldon Spring Heights and Old Kane around 
  1205 PM CDT.
  O'Fallon, Weldon Spring and Cottleville around 1210 PM CDT.

Other locations in the path of these severe thunderstorms include St.
Peters, Brighton, Harvester, St. Charles, Maryland Heights, Kemper,
Girard, Shipman, Champ, Florissant, Hazelwood, Bridgeton, Orchard
Farms, Elsah and Portage Des Sioux.

This includes the following highways...
 Interstate 44 in Missouri between exits 272 and 277.
 Interstate 70 in Missouri between exits 203 and 231.

This also includes Babler Memorial State Park, Scott Joplin Historic
Site, Castlewood State Park, Confluence State Park, First Missouri
State Capitol Historic Site, Pere Marquette State Park, Beaver Dam
State Park, and Horseshoe Lake State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3853 9023 3853 9093 3862 9121 3895 9084
      3929 9051 3949 8970 3918 8970
TIME...MOT...LOC 1650Z 247DEG 37KT 3934 9024 3902 9051 3872 9091 

HAIL...1.00IN
WIND...70MPH
 
$$

MRM
1 follow-up statement
423 
WWUS53 KLSX 271709
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1209 PM CDT Thu May 27 2021

MOC113-271718-
/O.CAN.KLSX.SV.W.0049.000000T0000Z-210527T1745Z/
Lincoln MO-
1209 PM CDT Thu May 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LINCOLN 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 700 PM CDT for
south central and southwestern Illinois...and east central Missouri.

LAT...LON 3853 9023 3853 9093 3860 9114 3892 9071
      3892 9069 3894 9069 3894 9066 3895 9067
      3900 9060 3933 9036 3949 8970 3918 8970
TIME...MOT...LOC 1708Z 251DEG 37KT 3939 9001 3888 9040 3858 9099 

$$

ILC013-061-083-117-119-163-MOC071-183-189-219-510-271745-
/O.CON.KLSX.SV.W.0049.000000T0000Z-210527T1745Z/
Calhoun IL-Greene IL-Madison IL-Macoupin IL-Jersey IL-St. Clair IL-
St. Louis City MO-St. Charles MO-Franklin MO-St. Louis MO-Warren MO-
1209 PM CDT Thu May 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1245 PM CDT
FOR SOUTHEASTERN CALHOUN...SOUTHEASTERN GREENE...WESTERN MADISON...
MACOUPIN...JERSEY AND NORTHWESTERN ST. CLAIR COUNTIES IN SOUTHWESTERN
ILLINOIS...ST. CHARLES...NORTHEASTERN FRANKLIN...ST. LOUIS AND
SOUTHEASTERN WARREN COUNTIES IN EAST CENTRAL MISSOURI AND ST. LOUIS
CITY...

At 1208 PM CDT, severe thunderstorms were located along a line
extending from near Palmyra to near Orchard Farms to Dutzow, moving
east at 45 mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
  Florissant, Elsah, Portage Des Sioux, Black Jack, Spanish Lake, 
  West Alton, New Melle, East Alton, Girard, Alton, Godfrey, Wood 
  River, Brighton, Roxana, Hartford, Wildwood, Bethalto, Spirit of 
  St. Louis Airport, Weldon Spring Heights, Rosewood Heights, 
  O'Fallon, St. Peters, Ballwin, Ellisville, Weldon Spring, 
  Cottleville, Clarkson Valley, Winchester, Dorsey, Manchester, Town 
  and Country, Bunker Hill, Prairietown, Harvester, Chesterfield, 
  Kirkwood, Maryland Heights, Des Peres, Frontenac, Warson Woods, 
  Crystal Lake Park, Huntleigh, Westwood and Country Life Acres.

This also includes Babler Memorial State Park, Scott Joplin Historic
Site, Castlewood State Park, Confluence State Park, First Missouri
State Capitol Historic Site, Pere Marquette State Park, Beaver Dam
State Park, and Horseshoe Lake State Park.
 
This includes the following highways...
 Interstate 44 in Missouri between exits 272 and 277.
 Interstate 70 in Missouri between exits 209 and 231.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3853 9023 3853 9093 3860 9114 3892 9071
      3892 9069 3894 9069 3894 9066 3895 9067
      3900 9060 3933 9036 3949 8970 3918 8970
TIME...MOT...LOC 1708Z 251DEG 37KT 3939 9001 3888 9040 3858 9099 

HAIL...1.00IN
WIND...70MPH
 
$$

MRM

The office that day

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

IssuedProductOfficeCountiesLasted
May 27, 11:13 AM CDTSevere Thunderstorm WarningLSXLincoln, Saint Charles, Warren47 min
May 27, 12:39 PM CDTAreal Flood AdvisoryLSXFranklin, Jefferson, Saint Charles, Saint Louis, City of Saint Louis3 hr
May 27, 1:09 PM CDTSevere Thunderstorm WarningLSXFranklin, Saint Louis51 min
May 27, 1:24 PM CDTSevere Thunderstorm WarningLSXCrawford, Gasconade51 min
May 27, 1:51 PM CDTSevere Thunderstorm WarningLSXCrawford, Franklin, Washington39 min
May 27, 2:46 PM CDTSevere Thunderstorm WarningLSXJefferson, Sainte Genevieve29 min
May 27, 11:32 AM CDTSevere Thunderstorm WarningLSXGreene, Macoupin43 min
May 27, 12:07 PM CDTSevere Thunderstorm WarningLSXGreene, Macoupin, Montgomery38 min
May 27, 12:26 PM CDTTornado WarningLSXMacoupin, Madison34 min
May 27, 12:56 PM CDTTornado WarningLSXBond, Macoupin, Madison, Montgomery28 min
May 27, 2:16 PM CDTAreal Flood AdvisoryLSXBond, Fayette3 hr
May 27, 2:31 PM CDTSevere Thunderstorm WarningLSXClinton, Fayette, Marion44 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2021Severe 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.