Alert archive / Illinois / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 47, NWS St. Louis, MO

March 30, 2017Macoupin County, Madison County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Mar 30, 2017, 12:37 PM CDT for Macoupin County, Madison County, Illinois. It was in force for 23 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 30, 2017, 12:37 PM CDT (17:37 UTC)
Expired: Mar 30, 2017, 1:00 PM CDT
In force: 23 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Macoupin County, IL, Madison County, IL

The radar

The St Louis radar (KLSX), 61 km from the middle of the area, began a volume at 17:37 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
Mar 30, 12:40 PM CDT	HAIL 1	2 Wnw Glen Carbon, IL	QUARTER-SIZED HAIL LASTED 1-2 MINUTES.
Mar 30, 12:45 PM CDT	HAIL 0.88	Edwardsville, IL	.
Mar 30, 12:50 PM CDT	HAIL 1.25	Bunker Hill, IL	.

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
Mar 30, 12:31 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 5.6 hours before the alert went out and 190 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 847 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 347 m²/s²
0-3 km storm-relative helicity: 373 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

999 
WUUS53 KLSX 301737
SVRLSX
ILC117-119-301800-
/O.NEW.KLSX.SV.W.0047.170330T1737Z-170330T1800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
1237 PM CDT THU MAR 30 2017

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Central Madison County in southwestern Illinois...
  Southeastern Macoupin County in southwestern Illinois...

* Until 100 PM CDT.

* At 1237 PM CDT, a severe thunderstorm was located over Pontoon
  Beach, moving northeast at 40 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...
  Granite City, Alton, Collinsville, Edwardsville, Glen Carbon, Wood
  River, Troy, Bethalto, Maryville, Pontoon Beach, Staunton, Madison,
  East Alton, South Roxana, Bunker Hill, Roxana, Hartford, Worden,
  Livingston and Wilsonville.

This includes Interstate 55 in Illinois between exits 23 and 41.
 
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 3866 8997 3866 9000 3873 9019 3877 9017
      3881 9012 3884 9011 3886 9013 3915 8998
      3903 8970 3900 8970
TIME...MOT...LOC 1737Z 206DEG 33KT 3876 9005 

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

Carney

1 follow-up statement

441 
WWUS53 KLSX 301749
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1249 PM CDT THU MAR 30 2017

ILC117-119-301800-
/O.CON.KLSX.SV.W.0047.000000T0000Z-170330T1800Z/
Madison IL-Macoupin IL-
1249 PM CDT THU MAR 30 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 100 PM CDT
FOR NORTHWESTERN MADISON AND SOUTHEASTERN MACOUPIN COUNTIES IN
SOUTHWESTERN ILLINOIS...

At 1249 PM CDT, a severe thunderstorm was located near Edwardsville,
moving northeast at 40 mph.

HAZARD...Quarter size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Damage to vehicles is expected. 

Locations impacted include...
Alton, Edwardsville, Glen Carbon, Wood River, Bethalto, Staunton,
East Alton, South Roxana, Bunker Hill, Roxana, Hartford, Worden,
Livingston, Wilsonville, West Alton, Sawyerville, Prairietown,
Dorsey, Carpenter and Rosewood Heights.

This includes Interstate 55 in Illinois between exits 30 and 41.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3875 8995 3881 9012 3882 9012 3884 9011
      3886 9013 3915 8998 3903 8970 3900 8970
TIME...MOT...LOC 1749Z 210DEG 33KT 3885 8996 

HAIL...1.00IN
WIND...<50MPH
 
$$

Carney

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 29, 8:55 PM CDT	Severe Thunderstorm Warning	LSX	Adams	35 min
Mar 30, 11:49 AM CDT	Special Weather Statement	LSX	Jersey	41 min
Mar 30, 12:05 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Greene, Jersey, Macoupin	40 min
Mar 30, 12:58 PM CDT	Severe Thunderstorm Warning	LSX	Macoupin, Madison, Montgomery	47 min
Mar 30, 2:19 PM CDT	Special Weather Statement	LSX	Fayette	41 min
Mar 30, 2:23 PM CDT	Severe Thunderstorm Warning	LSX	Fayette	23 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.