Alert archive / Illinois / Mesoscale Discussions in 2012

Mesoscale Discussion 1191

June 16, 201216 counties in Illinois

The Storm Prediction Center issued this mesoscale discussion at Jun 16, 2012, 6:10 PM CDT for 16 counties in Illinois. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jun 16, 2012, 6:10 PM CDT (23:10 UTC)
Expired: Jun 16, 2012, 7:45 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center

Counties Bureau County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Henry County, IL, Kane County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Whiteside County, IL, Will County, IL

The radar

The Chicago radar (KLOT), 100 km from the middle of the area, began a volume at 23:11 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.

Severe Thunderstorm Watch 402Jun 16, 6:40 PM CDT

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.2 hours before the alert went out and 102 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: 208 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 515 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 130 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.2

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.

Issued	Product	Office	Counties	Lasted
Jun 16, 12:42 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Bureau, Carroll, Fulton, Hancock and 13 more	63 min
Jun 16, 2:45 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Bureau, Calhoun, Carroll, Cass and 23 more	6 hr
Jun 16, 3:38 PM CDT	Mesoscale Discussion	SPC	Carroll, Fulton, Hancock, Henderson, Henry, Knox and 6 more	97 min
Jun 16, 6:40 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more	6 hr

Nearby

Mesoscale Discussions in Illinois, 2012 Every mesoscale discussion in 2012

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.