Alert archive / Illinois / Mesoscale Discussions in 2015

Mesoscale Discussion 979

June 11, 201522 counties in Illinois

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2015, 7:53 PM CDT for 22 counties in Illinois. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Jun 11, 2015, 7:53 PM CDT (00:53 UTC)
Expired
Jun 11, 2015, 9:00 PM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 22 counties

Bureau County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Henry County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Peoria County, IL, Putnam County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Woodford County, IL

The radar

The Lincoln radar (KILX), 91 km from the middle of the area, began a volume at 00:53 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

Davenport, (KDVN), launched 00:00Z, 0.9 hours before the alert went out and 105 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, Davenport, at 00:00Z on 2015-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 77 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, Davenport, at 00:00Z on 2015-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 192 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
77 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
1037 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
192 m²/s²
0-3 km storm-relative helicity
344 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 8:13 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Fulton, Hancock, Henderson and 14 more92 min
Jun 11, 8:25 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Cass, Fulton, Hancock, Henderson and 7 more5 hr
Jun 11, 10:30 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Hancock, Henderson, McDonough and 2 more90 min

Nearby

Mesoscale Discussions in Illinois, 2015Every mesoscale discussion in 2015

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.