Alert archive / Illinois / Mesoscale Discussions in 2014

Mesoscale Discussion 1683

September 5, 201437 counties in Illinois; 32 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2014, 5:11 PM CDT for 37 counties in Illinois; 32 counties in Missouri. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Sep 5, 2014, 5:11 PM CDT (22:11 UTC)
Expired: Sep 5, 2014, 6:45 PM CDT
In force: 94 min
Issued by: the Storm Prediction Center

All 69 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clinton County, IL, Coles County, IL, DeWitt County, IL, Douglas County, IL, Fayette County, IL, Fulton County, IL, Greene County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Audrain County, MO, Benton County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Dallas County, MO, Franklin County, MO, Gasconade County, MO, Hickory County, MO, Jefferson County, MO, Laclede County, MO, Lincoln County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Phelps County, MO, Pike County, MO, Polk County, MO, Pulaski County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 57 km from the middle of the area, began a volume at 22:12 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

Lincoln, IL (KILX), launched 12:00Z, 10.2 hours before the alert went out and 200 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: 1924 J/kg
Mixed-layer CIN: -118 J/kg
Mixed-layer LCL: 1162 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: -21 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Sep 5, 1:19 PM CDT	Mesoscale Discussion	SPC	Cook, Grundy, Iroquois, Kankakee, Will	86 min
Sep 5, 2:02 PM CDT	Severe Thunderstorm Watch	SPC	Cook, DuPage, Ford, Grundy, Iroquois, Kane and 6 more	6 hr
Sep 5, 2:38 PM CDT	Mesoscale Discussion	SPC	Bond, Brown, Calhoun, Cass, Champaign, Christian and 47 more	67 min
Sep 5, 3:43 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Bond, Brown, Calhoun, Cass, Champaign and 31 more	6 hr
Sep 5, 5:36 PM CDT	Mesoscale Discussion	SPC	Cook, DuPage, Ford, Grundy, Iroquois, Kankakee and 3 more	84 min

Nearby

Mesoscale Discussions in Illinois, 2014 Mesoscale Discussions in Missouri, 2014 Every mesoscale discussion in 2014

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.