Alert archive / Illinois / Mesoscale Discussions in 2017

Mesoscale Discussion 847

May 26, 201718 counties in Illinois; 14 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at May 26, 2017, 4:31 PM CDT for 18 counties in Illinois; 14 counties in Indiana. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
May 26, 2017, 4:31 PM CDT (21:31 UTC)
Expired
May 26, 2017, 5:30 PM CDT
In force
59 min
Issued by
the Storm Prediction Center
All 32 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, Macon County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Peoria County, IL, Piatt County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Benton 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, Newton County, IN, Pulaski County, IN, Tippecanoe County, IN, Warren County, IN, White County, IN

The radar

The Lincoln radar (KILX), 91 km from the middle of the area, began a volume at 21:32 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.5 hours before the alert went out and 40 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.

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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, 2:45 PM CDTTornado WatchSPCChampaign, DeWitt, Ford, Fulton, Iroquois, Kankakee and 10 more5 hr
May 26, 6:30 PM CDTMesoscale DiscussionSPCChampaign, Clark, Coles, Cumberland, Douglas, Edgar and 3 more90 min

Nearby

Mesoscale Discussions in Illinois, 2017Mesoscale Discussions in Indiana, 2017Every mesoscale discussion 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.