Alert archive / Illinois / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 2, NWS Lincoln, IL

February 28, 2017Knox County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Feb 28, 2017, 3:50 PM CST for Knox County, Illinois. It was in force for 26 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: Feb 28, 2017, 3:50 PM CST (21:50 UTC)
Expired: Feb 28, 2017, 4:16 PM CST
In force: 26 min
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Knox County, IL

The radar

The Quad Cities radar (KDVN), 66 km from the middle of the area, began a volume at 21:53 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
Feb 28, 4:10 PM CST	HAIL 1.25	Altona, IL	.
Feb 28, 4:10 PM CST	HAIL 1.25	Altona, IL	CORRECTION FOR ESTIMATED.

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
Feb 28, 2:57 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.8 hours before the alert went out and 64 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: 30 J/kg
Mixed-layer CIN: -241 J/kg
Mixed-layer LCL: 771 m above ground
0-6 km bulk shear: 80 kt
0-1 km storm-relative helicity: 223 m²/s²
0-3 km storm-relative helicity: 294 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

628 
WUUS53 KILX 282150
SVRILX
ILC095-282230-
/O.NEW.KILX.SV.W.0002.170228T2150Z-170228T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Lincoln IL
350 PM CST TUE FEB 28 2017

The National Weather Service in Lincoln has issued a

* Severe Thunderstorm Warning for...
  Northern Knox County in west central Illinois...

* Until 430 PM CST

* At 349 PM CST, a severe thunderstorm was located over Rio, or 9
  miles north of Galesburg, moving east at 50 mph.

  HAZARD...60 mph wind gusts and half dollar size hail. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Wataga, Oneida, Altona, Victoria, Rio and Henderson. 

This includes Interstate 74 between mile markers 34 and 42.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

A tornado watch remains in effect for the warned area. Tornadoes can
develop quickly from severe thunderstorms. Although a tornado is not
immediately likely, if one is spotted, act quickly and move to a
place of safety inside a sturdy structure such as a basement or small
interior room.

&&

A tornado watch remains in effect until 1000 PM CST for west central
Illinois.

LAT...LON 4115 9000 4102 8999 4103 9044 4115 9044
TIME...MOT...LOC 2149Z 249DEG 42KT 4109 9039 

HAIL...1.25IN
WIND...60MPH
 
$$

Shimon

2 follow-up statements

381 
WWUS53 KILX 282159
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
359 PM CST TUE FEB 28 2017

ILC095-282230-
/O.CON.KILX.SV.W.0002.000000T0000Z-170228T2230Z/
Knox-
359 PM CST TUE FEB 28 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM CST
FOR NORTHERN KNOX COUNTY...

At 359 PM CST, a severe thunderstorm was located near Oneida, or 11
miles north of Galesburg, moving east at 45 mph.

HAZARD...60 mph wind gusts and half dollar size hail. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Oneida, Altona and Rio. 

This includes Interstate 74 between mile markers 34 and 40.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

A tornado watch remains in effect for the warned area. Tornadoes can
develop quickly from severe thunderstorms. Although a tornado is not
immediately likely, if one is spotted act quickly and move to a place
of safety inside a sturdy structure, such as a basement or small
interior room.

&&

A tornado watch remains in effect until 1000 PM CST for west central
Illinois.

LAT...LON 4106 8999 4105 9039 4115 9044 4115 9000
TIME...MOT...LOC 2159Z 250DEG 37KT 4110 9030 

HAIL...1.25IN
WIND...60MPH
 
$$

Shimon

790 
WWUS53 KILX 282216
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
416 PM CST TUE FEB 28 2017

ILC095-282226-
/O.CAN.KILX.SV.W.0002.000000T0000Z-170228T2230Z/
Knox-
416 PM CST TUE FEB 28 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN KNOX COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning has been cancelled.

A tornado watch remains in effect until 1000 PM CST for west central
Illinois.

LAT...LON 4106 8999 4105 9039 4115 9044 4115 9000
TIME...MOT...LOC 2215Z 249DEG 42KT 4117 9005 

$$

Shimon

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 28, 3:35 PM CST	Severe Thunderstorm Warning	ILX	Stark	25 min
Feb 28, 4:11 PM CST	Severe Thunderstorm Warning	ILX	Knox	36 min
Feb 28, 4:33 PM CST	Severe Thunderstorm Warning	ILX	Morgan, Scott	29 min
Feb 28, 4:44 PM CST	Severe Thunderstorm Warning	ILX	Marshall, Peoria, Stark	51 min
Feb 28, 5:05 PM CST	Tornado Warning	ILX	Marshall, Peoria, Woodford	25 min
Feb 28, 5:28 PM CST	Tornado Warning Tornado observed	ILX	Marshall, Woodford	32 min
Feb 28, 5:32 PM CST	Severe Thunderstorm Warning	ILX	Marshall	28 min
Feb 28, 5:36 PM CST	Tornado Warning	ILX	Christian	24 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.