Alert archive / Illinois / Mesoscale Discussions in 2016

Mesoscale Discussion 1891

December 17, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Dec 17, 2016, 5:32 PM CST for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Dec 17, 2016, 5:32 PM CST (23:32 UTC)
Expired: Dec 17, 2016, 11:30 PM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 57 counties

Alexander County, IL, Clay County, IL, Crawford County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Clay County, IN, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Monroe County, IN, Morgan County, IN, Orange County, IN, Owen County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Sullivan County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Crittenden County, KY, Henderson County, KY, Livingston County, KY, McCracken County, KY, Union County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Mississippi County, MO, Perry County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Evansville,IN radar (KVWX), 80 km from the middle of the area, began a volume at 23:33 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 nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.5 hours before the alert went out and 270 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 611 m above ground
0-6 km bulk shear: 74 kt
0-1 km storm-relative helicity: 734 m²/s²
0-3 km storm-relative helicity: 836 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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.

Issued	Product	Office	Counties	Lasted
Dec 17, 1:00 PM CST	Mesoscale Discussion	SPC	Hardin, Massac, Pope	2 hr
Dec 17, 1:42 PM CST	Tornado Watch	SPC	Crawford, Floyd, Harrison, Perry	7 hr
Dec 16, 10:42 PM CST	Mesoscale Discussion	SPC	Campbell, Greenup, Lewis	5 hr
Dec 17, 5:45 PM CST	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Bourbon and 57 more	90 min

Nearby

Mesoscale Discussions in Illinois, 2016 Mesoscale Discussions in Indiana, 2016 Mesoscale Discussions in Missouri, 2016 Every mesoscale discussion in 2016

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.