Alert archive / Illinois / Tornado Warnings in 2017

Tornado Warning 4, NWS Chicago, IL

February 28, 2017Grundy County, LaSalle County, Livingston County, Illinois

NWS Chicago, IL issued this tornado warning at Feb 28, 2017, 6:13 PM CST for Grundy County, LaSalle County, Livingston County, Illinois. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Feb 28, 2017, 6:13 PM CST (00:13 UTC)
Expired: Feb 28, 2017, 6:45 PM CST
In force: 32 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.75 in

Counties Grundy County, IL, LaSalle County, IL, Livingston County, IL

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

Lincoln, IL (KILX), launched 00:00Z, 0.2 hours before the alert went out and 106 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: 687 J/kg
Mixed-layer CIN: -73 J/kg
Mixed-layer LCL: 887 m above ground
0-6 km bulk shear: 72 kt
0-1 km storm-relative helicity: 395 m²/s²
0-3 km storm-relative helicity: 431 m²/s²
Significant tornado parameter: 1.6
Supercell composite: 6.7

Open this sounding in Storm Lab

The text

As transmitted.

070 
WFUS53 KLOT 010013
TORLOT
ILC063-099-105-010100-
/O.NEW.KLOT.TO.W.0004.170301T0013Z-170301T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville Il
613 PM CST TUE FEB 28 2017

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Northeastern Livingston County in central Illinois...
  East central La Salle County in north central Illinois...
  Southwestern Grundy County in northeastern Illinois...

* Until 700 PM CST
    
* At 612 PM CST, a severe thunderstorm capable of producing a tornado
  was located near Streator, moving east at 45 mph.

  HAZARD...Tornado and golf ball size hail. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* This dangerous storm will be near...
  Dwight and Mazon around 635 PM CST. 

Other locations impacted by this tornadic thunderstorm include
Ransom, Verona and Kinsman.

Including the following interstate...
 I-55 between mile markers 212 and 222.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4103 8871 4113 8875 4128 8842 4103 8834
TIME...MOT...LOC 0012Z 252DEG 39KT 4108 8871 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

BMD

3 follow-up statements

484 
WWUS53 KLOT 010027
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville Il
627 PM CST TUE FEB 28 2017

ILC099-010036-
/O.CAN.KLOT.TO.W.0004.000000T0000Z-170301T0100Z/
La Salle IL-
627 PM CST TUE FEB 28 2017

...THE TORNADO WARNING FOR EAST CENTRAL LA SALLE COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

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

LAT...LON 4111 8858 4117 8858 4128 8842 4104 8834
TIME...MOT...LOC 0026Z 252DEG 39KT 4113 8851 

$$

ILC063-105-010100-
/O.CON.KLOT.TO.W.0004.000000T0000Z-170301T0100Z/
Livingston IL-Grundy IL-
627 PM CST TUE FEB 28 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM CST FOR NORTH
CENTRAL LIVINGSTON AND SOUTHWESTERN GRUNDY COUNTIES...
    
At 626 PM CST, a severe thunderstorm capable of producing a tornado
was located northwest of Dwight, moving east at 45 mph.

HAZARD...Tornado and golf ball size hail. 

SOURCE...Radar indicated rotation. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

This dangerous storm will be near...
  Dwight and Mazon around 635 PM CST. 

Other locations impacted by this tornadic thunderstorm include
Verona.

LAT...LON 4111 8858 4117 8858 4128 8842 4104 8834
TIME...MOT...LOC 0026Z 252DEG 39KT 4113 8851 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

BMD

734 
WWUS53 KLOT 010038
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville Il
638 PM CST TUE FEB 28 2017

ILC105-010048-
/O.CAN.KLOT.TO.W.0004.000000T0000Z-170301T0100Z/
Livingston IL-
638 PM CST TUE FEB 28 2017

...THE TORNADO WARNING FOR NORTHEASTERN LIVINGSTON COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

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

LAT...LON 4115 8849 4122 8840 4111 8836 4111 8846
TIME...MOT...LOC 0038Z 258DEG 35KT 4114 8835 

$$

ILC063-010100-
/O.CON.KLOT.TO.W.0004.000000T0000Z-170301T0100Z/
Grundy IL-
638 PM CST TUE FEB 28 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM CST FOR SOUTH
CENTRAL GRUNDY COUNTY...
    
At 638 PM CST, a severe thunderstorm capable of producing a tornado 
was located near Gardner, or northeast of Dwight, moving east at 40 
mph.

HAZARD...Tornado and quarter size hail. 

SOURCE...Radar indicated rotation. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

This tornadic thunderstorm will remain over mainly rural areas of
south central Grundy County.

LAT...LON 4115 8849 4122 8840 4111 8836 4111 8846
TIME...MOT...LOC 0038Z 258DEG 35KT 4114 8835 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

BMD

929 
WWUS53 KLOT 010045
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville Il
645 PM CST TUE FEB 28 2017

ILC063-010055-
/O.CAN.KLOT.TO.W.0004.000000T0000Z-170301T0100Z/
Grundy IL-
645 PM CST TUE FEB 28 2017

...THE TORNADO WARNING FOR SOUTH CENTRAL GRUNDY 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 central and
northeastern Illinois.

LAT...LON 4115 8849 4122 8840 4111 8836 4111 8846
TIME...MOT...LOC 0044Z 252DEG 39KT 4117 8824 

$$

BMD

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 28, 6:00 PM CST	Severe Thunderstorm Warning	LOT	Cook, Grundy, Kendall, Will	45 min
Feb 28, 6:24 PM CST	Severe Thunderstorm Warning	LOT	LaSalle	51 min
Feb 28, 6:26 PM CST	Areal Flood Advisory	LOT	Cook, Grundy, Kendall, LaSalle, Livingston, Will	3 hr
Feb 28, 6:44 PM CST	Severe Thunderstorm Warning	LOT	Kankakee, Will	46 min
Feb 28, 6:44 PM CST	Severe Thunderstorm Warning	LOT	Cook, Will	46 min
Feb 28, 7:04 PM CST	Severe Thunderstorm Warning	LOT	Grundy, Kendall, Will	41 min
Feb 28, 7:41 PM CST	Severe Thunderstorm Warning	LOT	LaSalle	34 min
Feb 28, 7:45 PM CST	Severe Thunderstorm Warning	LOT	Cook, Kankakee, Will	45 min
Feb 28, 8:04 PM CST	Severe Thunderstorm Warning	LOT	Grundy, LaSalle, Will	26 min
Feb 28, 8:24 PM CST	Special Marine Warning	LOT		96 min
Feb 28, 8:35 PM CST	Severe Thunderstorm Warning	LOT	DeKalb, Kendall, LaSalle, Lee	40 min
Feb 28, 8:51 PM CST	Areal Flood Advisory	LOT	Cook, DeKalb, DuPage, Grundy, Kane, Kankakee and 4 more	6 hr
Feb 28, 8:57 PM CST	Severe Thunderstorm Warning	LOT	Cook, Will	37 min
Feb 28, 9:09 PM CST	Areal Flood Warning	LOT	Cook, Grundy, Kendall, Will	6 hr
Feb 28, 9:34 PM CST	Severe Thunderstorm Warning	LOT	LaSalle	56 min
Feb 28, 9:57 PM CST	Special Weather Statement	LOT	Cook	33 min
Feb 28, 10:18 PM CST	Severe Thunderstorm Warning	LOT	DeKalb, DuPage, Grundy, Kane, Kendall, Will	27 min
Feb 28, 10:56 PM CST	Special Marine Warning	LOT		64 min
Feb 28, 11:20 PM CST	Special Weather Statement	LOT	Ford, Iroquois	25 min
Feb 28, 11:27 PM CST	River Flood Warning	LOT	Lake	5 days
Feb 28, 11:28 PM CST	River Flood Warning	LOT	Cook	31 hr
Feb 28, 11:34 PM CST	River Flood Advisory	LOT	Kane, Kendall	7 days
Feb 28, 11:38 PM CST	River Flood Advisory	LOT	Cook	36 hr
Mar 1, 12:21 AM CST	River Flood Warning	LOT	Will	27 hr
Mar 1, 12:21 AM CST	River Flood Warning	LOT	Bureau, LaSalle, Putnam	72 hr

Nearby

Tornado Warnings in Illinois, 2017 Every tornado warning in 2017 Tornadoes 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; the sounding from the Mesonet's radiosonde archive.