Alert archive / Illinois / Tornado Warnings in 2018

Tornado Warning 30, NWS Lincoln, IL

December 1, 2018DeWitt County, Macon County, Illinois

NWS Lincoln, IL issued this tornado warning at Dec 1, 2018, 6:13 PM CST for DeWitt County, Macon County, Illinois. It was in force for 32 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: Dec 1, 2018, 6:13 PM CST (00:13 UTC)
Expired: Dec 1, 2018, 6:45 PM CST
In force: 32 min
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties DeWitt County, IL, Macon County, IL

The radar

The Lincoln radar (KILX), 37 km from the middle of the area, began a volume at 00:17 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
Dec 1, 6:31 PM CST	TORNADO 1	2 Sse Maroa, IL	PATH LENGTH 1.1 MILES, MAX WIDTH 320 YARDS, PEAK WIND SPEED 100 MPH. WAS ON THE GROUND FOR 2 MINUTES, LIFTING 1.4 MILES SOUTHEAST OF MAROA.
Dec 1, 6:31 PM CST	TORNADO	2 Sse Maroa, IL	NWS SURVEY RATES TORNADO EF-1.

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
Dec 1, 2:16 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 42 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: 653 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 628 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 392 m²/s²
0-3 km storm-relative helicity: 444 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 6.5

Open this sounding in Storm Lab

The text

As transmitted.

277 
WFUS53 KILX 020013
TORILX
ILC039-115-020045-
/O.NEW.KILX.TO.W.0030.181202T0013Z-181202T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Lincoln IL
613 PM CST SAT DEC 1 2018

The National Weather Service in Lincoln has issued a

* Tornado Warning for...
  Southwestern De Witt County in central Illinois...
  Northwestern Macon County in central Illinois...

* Until 645 PM CST.
    
* At 612 PM CST, a severe thunderstorm capable of producing a tornado
  was located over Warrensburg, or near Decatur, moving northeast at
  35 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 dangerous storm will be near...
  Forsyth around 620 PM CST.
  Maroa around 630 PM CST.

Other locations impacted by this tornadic thunderstorm include
Rowell.

This includes Interstate 72 between mile markers 133 and 142.
 
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.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 3982 8900 3987 8917 4010 8906 4009 8879
TIME...MOT...LOC 0012Z 206DEG 30KT 3990 8904 

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

$$

Auten

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 1, 6:27 PM CST	Flash Flood Warning	ILX	Tazewell	3 hr
Dec 1, 6:42 PM CST	Tornado Warning	ILX	DeWitt, McLean	33 min
Dec 1, 7:13 PM CST	Tornado Warning Tornado observedConsiderable damage threat	ILX	McLean	32 min
Dec 1, 7:47 PM CST	Tornado Warning Tornado observed	ILX	McLean	28 min
Dec 1, 8:53 PM CST	River Flood Warning	ILX	Clay, Richland	13 hr

Nearby

Tornado Warnings in Illinois, 2018 Every tornado warning in 2018 Tornadoes in 2018

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.