Alert archive / Illinois / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 86, NWS St. Louis, MO

May 19, 20175 counties in Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 19, 2017, 5:36 AM CDT for 5 counties in Illinois. It was in force for 69 min. 2 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, 5:36 AM CDT (10:36 UTC)
Expired
May 19, 2017, 6:45 AM CDT
In force
69 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
80.0 mph

Counties Bond County, IL, Fayette County, IL, Greene County, IL, Macoupin County, IL, Montgomery County, IL

The radar

The St Louis radar (KLSX), 94 km from the middle of the area, began a volume at 10:39 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 19, 5:47 AM CDTTSTM WND GST 64Shipman, IL
May 19, 6:06 AM CDTTSTM WND DMGNilwood, ILTWO 80 BY 30 FOOT STORAGE SHEDS WERE DESTROYED.

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 19, 4:16 AM CDTSevere Thunderstorm WatchSPC3 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 10.6 hours before the alert went out and 150 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 2017-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 631 joules per kilogram.LCLLFCEL10008507005003002001001 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 2017-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.193958Sfc1 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
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.

729 
WUUS53 KLSX 191036
SVRLSX
ILC005-051-061-117-135-191145-
/O.NEW.KLSX.SV.W.0086.170519T1036Z-170519T1145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
536 AM CDT FRI MAY 19 2017

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Bond County in south central Illinois...
  Southeastern Greene County in southwestern Illinois...
  Northwestern Fayette County in south central Illinois...
  Macoupin County in southwestern Illinois...
  Montgomery County in south central Illinois...

* Until 645 AM CDT.

* At 536 AM CDT, severe thunderstorms were located along a line
  extending from near Carrollton to Mascoutah, moving northeast at 60
  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...
  Greenville, Litchfield, Hillsboro, Carlinville, Staunton, Virden,
  Gillespie, Nokomis, Carrollton, Brighton, Girard, Mount Olive,
  Bunker Hill, Benld, Greenfield, Ramsey, Raymond, Witt, White Oak
  and Pocahontas.

This includes the following highways...
 Interstate 70 in Illinois between exits 36 and 52.
 Interstate 55 in Illinois between exits 41 and 63.

This also includes  Ramsey Lake State Park, Beaver Dam State Park,
and Lake Lou Yaeger.
 
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 3875 8929 3874 8956 3874 8959 3900 8964
      3900 9014 3926 9015 3922 9031 3917 9031
      3917 9041 3926 9053 3952 9016 3952 8953
      3935 8953 3935 8914 3922 8914 3921 8899
TIME...MOT...LOC 1036Z 230DEG 53KT 3929 9034 3850 8980 

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

Tilly
3 follow-up statements
874 
WWUS53 KLSX 191102
SVSLSX

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

ILC061-191111-
/O.CAN.KLSX.SV.W.0086.000000T0000Z-170519T1145Z/
Greene IL-
602 AM CDT FRI MAY 19 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN GREENE 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 3875 8929 3874 8959 3900 8964 3900 9001
      3952 9015 3952 8953 3935 8953 3935 8914
      3922 8914 3921 8899
TIME...MOT...LOC 1101Z 224DEG 38KT 3952 8999 3867 8960 

$$

ILC005-051-117-135-191145-
/O.CON.KLSX.SV.W.0086.000000T0000Z-170519T1145Z/
Bond IL-Fayette IL-Macoupin IL-Montgomery IL-
602 AM CDT FRI MAY 19 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 AM CDT
FOR BOND...NORTHWESTERN FAYETTE...MACOUPIN AND MONTGOMERY COUNTIES...

At 601 AM CDT, severe thunderstorms were located along a line
extending from near Palmyra to near St. Rose, moving northeast at 45
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...
Greenville, Litchfield, Hillsboro, Carlinville, Staunton, Virden,
Gillespie, Nokomis, Girard, Mount Olive, Bunker Hill, Benld, Ramsey,
Raymond, Witt, White Oak, Pocahontas, Farmersville, Palmyra and
Taylor Springs.

This also includes  Ramsey Lake State Park, Beaver Dam State Park,
and Lake Lou Yaeger.
 
This includes the following highways...
 Interstate 70 in Illinois between exits 36 and 52.
 Interstate 55 in Illinois between exits 41 and 63.

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 3875 8929 3874 8959 3900 8964 3900 9001
      3952 9015 3952 8953 3935 8953 3935 8914
      3922 8914 3921 8899
TIME...MOT...LOC 1101Z 224DEG 38KT 3952 8999 3867 8960 

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

Tilly
591 
WWUS53 KLSX 191124
SVSLSX

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

ILC117-191133-
/O.CAN.KLSX.SV.W.0086.000000T0000Z-170519T1145Z/
Macoupin IL-
624 AM CDT FRI MAY 19 2017

...THE SEVERE THUNDERSTORM WARNING FOR MACOUPIN 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 3875 8929 3874 8959 3900 8964 3952 8970
      3952 8953 3935 8953 3935 8914 3922 8914
      3921 8899
TIME...MOT...LOC 1123Z 222DEG 55KT 3952 8956 3882 8942 

$$

ILC005-051-135-191145-
/O.CON.KLSX.SV.W.0086.000000T0000Z-170519T1145Z/
Bond IL-Fayette IL-Montgomery IL-
624 AM CDT FRI MAY 19 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 AM CDT
FOR BOND...NORTHWESTERN FAYETTE AND MONTGOMERY COUNTIES...

At 623 AM CDT, severe thunderstorms were located along a line
extending from White Oak to near Beaver Creek, moving northeast at 65
mph.

HAZARD...60 mph wind gusts. 

SOURCE...Trained weather spotters. 

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

Locations impacted include...
Greenville, Litchfield, Hillsboro, Nokomis, Ramsey, Raymond, Witt,
White Oak, Pocahontas, Farmersville, Taylor Springs, Coffeen,
Mulberry Grove, Schram City, Tamalco, Sorento, Beaver Creek, Woburn,
Van Burensburg and Reno.

This also includes  Ramsey Lake State Park and Lake Lou Yaeger.
 
This includes the following highways...
 Interstate 70 in Illinois between exits 36 and 52.
 Interstate 55 in Illinois between exits 60 and 63.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage across Macoupin County. SEEK SHELTER NOW inside a sturdy 
structure and stay away from windows.
 
&&

LAT...LON 3875 8929 3874 8959 3900 8964 3952 8970
      3952 8953 3935 8953 3935 8914 3922 8914
      3921 8899
TIME...MOT...LOC 1123Z 222DEG 55KT 3952 8956 3882 8942 

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

Tilly
351 
WWUS53 KLSX 191144
SVSLSX

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

ILC005-051-135-191153-
/O.EXP.KLSX.SV.W.0086.000000T0000Z-170519T1145Z/
Bond IL-Fayette IL-Montgomery IL-
644 AM CDT FRI MAY 19 2017

...THE SEVERE THUNDERSTORM WARNING FOR BOND...NORTHWESTERN FAYETTE
AND MONTGOMERY COUNTIES WILL EXPIRE AT 645 AM CDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore the warning will
be 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 Illinois.

LAT...LON 3875 8929 3874 8959 3900 8964 3952 8970
      3952 8953 3935 8953 3935 8914 3922 8914
      3921 8899
TIME...MOT...LOC 1143Z 247DEG 48KT 3938 8921 3906 8900 

$$

Tilly

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 4:37 AM CDTSevere Thunderstorm WarningLSXCalhoun53 min
May 19, 4:39 AM CDTSevere Thunderstorm WarningLSXCalhoun, Monroe66 min
May 19, 5:13 AM CDTSevere Thunderstorm WarningLSXClinton, Jersey, Madison, Saint Clair62 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2017Every 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.