Alert archive / Indiana / Tornado Watches in 2017

Tornado Watch 269

May 26, 201716 counties in Illinois; 17 counties in Indiana

The Storm Prediction Center issued this tornado watch at May 26, 2017, 2:45 PM CDT for 16 counties in Illinois; 17 counties in Indiana. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 26, 2017, 2:45 PM CDT (19:45 UTC)
Expired
May 26, 2017, 8:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 33 counties

Champaign County, IL, DeWitt County, IL, Ford County, IL, Fulton County, IL, Iroquois County, IL, Kankakee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Peoria County, IL, Piatt County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Benton County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Fountain County, IN, Fulton County, IN, Howard County, IN, Jasper County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Pulaski County, IN, Tippecanoe County, IN, Vermillion County, IN, Warren County, IN, White County, IN

The radar

The Lincoln radar (KILX), 92 km from the middle of the area, began a volume at 19:47 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
60%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 26, 3:11 PM CDTSevere Thunderstorm WarningILXMcLean, Tazewell, Woodford23 min
May 26, 3:48 PM CDTSevere Thunderstorm WarningLOTLivingston42 min
May 26, 4:05 PM CDTSevere Thunderstorm WarningILXMcLean40 min
May 26, 4:06 PM CDTSevere Thunderstorm WarningLOTFord, Livingston39 min
May 26, 4:35 PM CDTTornado WarningLOTFord, Iroquois, Livingston40 min
May 26, 5:10 PM CDTTornado WarningILXChampaign, Vermilion35 min
May 26, 5:10 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois45 min
May 26, 5:43 PM CDTSevere Thunderstorm WarningILXVermilion47 min
May 26, 5:49 PM CDTSevere Thunderstorm WarningINDFountain, Warren41 min
May 26, 6:06 PM CDTFlash Flood WarningILXVermilion11 hr
May 26, 6:21 PM CDTSevere Thunderstorm WarningILXVermilion24 min
May 26, 6:27 PM CDTTornado WarningINDFountain, Montgomery, Warren48 min
May 26, 7:06 PM CDTSevere Thunderstorm WarningINDBoone, Clinton, Hendricks, Montgomery, Tippecanoe, Tipton39 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, 7.8 hours before the alert went out and 62 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 2017-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2017-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1724 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

047 
WWUS20 KWNS 261943
SEL9  
SPC WW 261943
ILZ000-INZ000-270100-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 269
NWS Storm Prediction Center Norman OK
245 PM CDT Fri May 26 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Central Illinois
  West-central Indiana

* Effective this Friday afternoon and evening from 245 PM until
  800 PM CDT.

* Primary threats include...
  A couple tornadoes possible
  Scattered large hail likely with isolated very large hail events
    to 2 inches in diameter possible
  Scattered damaging wind gusts to 70 mph likely

SUMMARY...A cluster of intense thunderstorms over central Illinois
will track eastward across the watch area this afternoon, posing a
risk of large hail, damaging winds, and a few tornadoes.

The tornado watch area is approximately along and 40 statute miles
north and south of a line from 25 miles west southwest of Peoria IL
to 45 miles east northeast of Lafayette IN. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU9).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 268...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 27030.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 1:25 PM CDTMesoscale DiscussionSPCChampaign, Coles, DeWitt, Douglas, Edgar, Ford and 8 more3 hr
May 26, 4:31 PM CDTMesoscale DiscussionSPCChampaign, DeWitt, Ford, Fulton, Iroquois, Kankakee and 12 more59 min
May 26, 6:30 PM CDTMesoscale DiscussionSPCChampaign, Clark, Coles, Cumberland, Douglas, Edgar and 3 more90 min

Nearby

Tornado Watches in Indiana, 2017Tornado Watches in Illinois, 2017Every tornado watch 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; radar from the NEXRAD Level II archive.