Alert archive / Illinois / Tornado Watches in 2019

Tornado Watch 231

May 24, 201921 counties in Illinois

The Storm Prediction Center issued this tornado watch at May 24, 2019, 12:36 PM CDT for 21 counties in Illinois. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
May 24, 2019, 12:36 PM CDT (17:36 UTC)
Expired
May 24, 2019, 5:02 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 21 counties

Cass County, IL, Champaign County, IL, DeWitt County, IL, Ford County, IL, Fulton County, IL, Iroquois County, IL, Knox County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Peoria County, IL, Piatt County, IL, Schuyler County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL

The radar

The Lincoln radar (KILX), 62 km from the middle of the area, began a volume at 17:40 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 24, 12:43 PM CDTTornado WarningILXFulton, Mason62 min
May 24, 1:25 PM CDTTornado Warning Tornado observedILXFulton, Mason, Tazewell35 min
May 24, 1:58 PM CDTTornado WarningILXMason, Tazewell47 min
May 24, 2:43 PM CDTSevere Thunderstorm WarningILXMcLean, Tazewell47 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 5.6 hours before the alert went out and 88 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 12:00Z on 2019-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 83 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2019-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 301 square meters per square second.19395878Sfc1 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
83 J/kg
Mixed-layer CIN
-282 J/kg
Mixed-layer LCL
943 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
301 m²/s²
0-3 km storm-relative helicity
344 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 12:15 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Champaign, Christian, Coles and 28 more90 min
May 24, 3:25 PM CDTMesoscale DiscussionSPCCarroll, Henderson, Henry, Jo Daviess, Knox, Mercer and 5 more65 min
May 24, 6:23 PM CDTTornado WatchSPCBureau, Carroll, Fulton, Grundy, Hancock, Henderson and 24 more4 hr

Nearby

Tornado Watches in Illinois, 2019Every tornado watch in 2019

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; radar from the NEXRAD Level II archive.