Alert archive / Illinois / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 85, NWS St. Louis, MO

May 19, 20174 counties in Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 19, 2017, 5:13 AM CDT for 4 counties in Illinois. It was in force for 62 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: May 19, 2017, 5:13 AM CDT (10:13 UTC)
Expired: May 19, 2017, 6:15 AM CDT
In force: 62 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 70.0 mph

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

The radar

The St Louis radar (KLSX), 52 km from the middle of the area, began a volume at 10:12 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

Time	Report	Where	Remark
May 19, 5:39 AM CDT	TSTM WND DMG	Wood River, IL	6 TO 10 FOOT TALL TREE BLOWN OVER...POWER OUT AROUND TOWN.
May 19, 5:42 AM CDT	TSTM WND GST 49	1 Nnw Bethalto, IL
May 19, 5:48 AM CDT	TSTM WND DMG	Troy, IL	SHED LIFT AND DEPOSITED IN WHEAT FIELD ON HWY 61 IN SOUTTH TROY

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.

Issued	Product	Office	Lasted
May 19, 4:16 AM CDT	Severe Thunderstorm Watch	SPC	3 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 10.2 hours before the alert went out and 194 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 631 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 2069 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 30 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

165 
WUUS53 KLSX 191013
SVRLSX
ILC027-083-119-163-191115-
/O.NEW.KLSX.SV.W.0085.170519T1013Z-170519T1115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
513 AM CDT FRI MAY 19 2017

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Northwestern Clinton County in south central Illinois...
  Madison County in southwestern Illinois...
  Jersey County in southwestern Illinois...
  St. Clair County in southwestern Illinois...

* Until 615 AM CDT.

* At 513 AM CDT, severe thunderstorms were located along a line
  extending from near Hardin to near Waterloo, moving northeast at 60
  mph.

  HAZARD...70 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings. 

* Locations impacted include...
  St. Louis, Belleville, Granite City, O'Fallon, Alton, East St.
  Louis, Collinsville, Edwardsville, Godfrey, Fairview Heights,
  Cahokia, Swansea, Glen Carbon, Shiloh, Wood River, Highland, Troy,
  Columbia, Bethalto and Jerseyville.

This includes the following highways...
 Interstate 70 in Illinois between exits 21 and 30.
 Interstate 55 in Illinois between exits 23 and 37.
 Interstate 64 in Illinois between exits 9 and 27.

This also includes  Horseshoe Lake State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3830 8990 3831 9002 3852 9026 3863 9018
      3872 9021 3880 9012 3885 9011 3896 9040
      3896 9053 3905 9059 3918 9058 3917 9031
      3922 9031 3922 9021 3926 9019 3926 9015
      3900 9014 3900 8964 3874 8960 3874 8930
TIME...MOT...LOC 1013Z 233DEG 50KT 3908 9060 3836 9013 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...70MPH
 
$$

Tilly

4 follow-up statements

248 
WWUS53 KLSX 191030
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
530 AM CDT FRI MAY 19 2017

ILC027-083-119-163-191115-
/O.CON.KLSX.SV.W.0085.000000T0000Z-170519T1115Z/
Clinton IL-Madison IL-Jersey IL-St. Clair IL-
530 AM CDT FRI MAY 19 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 AM CDT
FOR NORTHWESTERN CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS...
MADISON...JERSEY AND ST. CLAIR COUNTIES IN SOUTHWESTERN ILLINOIS...

At 530 AM CDT, severe thunderstorms were located along a line
extending from Old Kane to near Freeburg, moving northeast at 55 mph.

These are very dangerous storms.

HAZARD...80 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely. 

Locations impacted include...
St. Louis, Belleville, Granite City, O'Fallon, Alton, East St. Louis,
Collinsville, Edwardsville, Godfrey, Fairview Heights, Cahokia,
Swansea, Glen Carbon, Shiloh, Wood River, Highland, Troy, Columbia,
Bethalto and Jerseyville.

This also includes  Horseshoe Lake State Park.
 
This includes the following highways...
 Interstate 70 in Illinois between exits 21 and 30.
 Interstate 55 in Illinois between exits 23 and 37.
 Interstate 64 in Illinois between exits 9 and 27.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

&&

LAT...LON 3830 8990 3831 9002 3852 9026 3863 9018
      3872 9021 3880 9012 3885 9011 3896 9040
      3896 9053 3905 9059 3918 9058 3917 9031
      3922 9031 3922 9021 3926 9019 3926 9015
      3900 9014 3900 8964 3874 8960 3874 8930
TIME...MOT...LOC 1030Z 236DEG 49KT 3919 9035 3847 8988 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...80MPH
 
$$

Tilly

761 
WWUS53 KLSX 191051
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
551 AM CDT FRI MAY 19 2017

ILC027-083-119-163-191115-
/O.CON.KLSX.SV.W.0085.000000T0000Z-170519T1115Z/
Clinton IL-Madison IL-Jersey IL-St. Clair IL-
551 AM CDT FRI MAY 19 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 AM CDT
FOR NORTHWESTERN CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS...
MADISON...NORTHEASTERN JERSEY AND EASTERN ST. CLAIR COUNTIES IN
SOUTHWESTERN ILLINOIS...

At 550 AM CDT, severe thunderstorms were located along a line
extending from 7 miles east of Greenfield to Aviston, moving east at
60 mph.

These are very dangerous storms.

HAZARD...80 mph wind gusts. 

SOURCE...Trained weather spotters. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely. 

Locations impacted include...
Belleville, Granite City, O'Fallon, Alton, East St. Louis,
Collinsville, Edwardsville, Godfrey, Fairview Heights, Swansea, Glen
Carbon, Shiloh, Wood River, Highland, Troy, Bethalto, Maryville,
Mascoutah, Pontoon Beach and Centreville.

This also includes  Horseshoe Lake State Park.
 
This includes the following highways...
 Interstate 70 in Illinois between exits 21 and 30.
 Interstate 55 in Illinois between exits 23 and 37.
 Interstate 64 in Illinois between exits 9 and 27.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

&&

LAT...LON 3830 8990 3855 9009 3882 9012 3885 9011
      3886 9012 3896 9019 3922 9028 3922 9021
      3926 9019 3926 9015 3900 9014 3900 8964
      3874 8960 3874 8930
TIME...MOT...LOC 1050Z 270DEG 50KT 3934 9007 3862 8960 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...80MPH
 
$$

Tilly

771 
WWUS53 KLSX 191100
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
600 AM CDT FRI MAY 19 2017

ILC083-191109-
/O.CAN.KLSX.SV.W.0085.000000T0000Z-170519T1115Z/
Jersey IL-
600 AM CDT FRI MAY 19 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN JERSEY 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 1000 AM CDT for
south central and southwestern Illinois.

LAT...LON 3840 8976 3900 9002 3900 8964 3888 8964
      3887 8962 3874 8960 3874 8930
TIME...MOT...LOC 1059Z 229DEG 53KT 3942 8994 3870 8947 

$$

ILC027-119-163-191115-
/O.CON.KLSX.SV.W.0085.000000T0000Z-170519T1115Z/
Clinton IL-Madison IL-St. Clair IL-
600 AM CDT FRI MAY 19 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 AM CDT
FOR NORTHWESTERN CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS...EASTERN
MADISON AND NORTHEASTERN ST. CLAIR COUNTIES IN SOUTHWESTERN
ILLINOIS...

At 559 AM CDT, severe thunderstorms were located along a line
extending from near Palmyra to near Jamestown, moving northeast at 60
mph.

These are very dangerous storms.

HAZARD...80 mph wind gusts. 

SOURCE...Trained weather spotters. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely. 

Locations impacted include...
Edwardsville, Glen Carbon, Highland, Troy, Mascoutah, Staunton,
Breese, Lebanon, New Baden, Scott AFB, Trenton, Aviston, St. Rose,
Germantown, Albers, St. Jacob, Worden, Marine, Livingston and
Alhambra.

This includes the following highways...
 Interstate 70 in Illinois between exits 21 and 30.
 Interstate 55 in Illinois between exits 23 and 37.
 Interstate 64 in Illinois between exits 23 and 27.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. These storms have the potential to cause
serious injury and significant property damage.

&&

LAT...LON 3840 8976 3900 9002 3900 8964 3888 8964
      3887 8962 3874 8960 3874 8930
TIME...MOT...LOC 1059Z 229DEG 53KT 3942 8994 3870 8947 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...80MPH
 
$$

Tilly

080 
WWUS53 KLSX 191116
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
616 AM CDT FRI MAY 19 2017

ILC027-119-163-191126-
/O.EXP.KLSX.SV.W.0085.000000T0000Z-170519T1115Z/
Clinton IL-Madison IL-St. Clair IL-
616 AM CDT FRI MAY 19 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CLINTON COUNTY IN
SOUTH CENTRAL ILLINOIS...EASTERN MADISON AND NORTHEASTERN ST. CLAIR
COUNTIES IN SOUTHWESTERN ILLINOIS HAS EXPIRED...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore the warning has
been allowed to expire.  However gusty winds are still possible with
these thunderstorms.

A severe thunderstorm watch remains in effect until 1000 AM CDT for
south central and southwestern Illinois.

LAT...LON 3840 8976 3900 9002 3900 8964 3888 8964
      3887 8962 3874 8960 3874 8930
TIME...MOT...LOC 1116Z 225DEG 44KT 3898 8962 3857 8946 

$$

Tilly

The office that day

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

Issued	Product	Office	Counties	Lasted
May 19, 4:37 AM CDT	Severe Thunderstorm Warning	LSX	Calhoun	53 min
May 19, 4:39 AM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Monroe	66 min
May 19, 5:36 AM CDT	Severe Thunderstorm Warning	LSX	Bond, Fayette, Greene, Macoupin, Montgomery	69 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2017 Every severe thunderstorm warning in 2017

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.