Alert archive / Illinois / Mesoscale Discussions in 2013

Mesoscale Discussion 481

April 16, 201327 counties in Illinois

The Storm Prediction Center issued this mesoscale discussion at Apr 16, 2013, 12:02 AM CDT for 27 counties in Illinois. It was in force for 28 min.

The area

The outline as issued.

The facts

Issued: Apr 16, 2013, 12:02 AM CDT (05:02 UTC)
Expired: Apr 16, 2013, 12:30 AM CDT
In force: 28 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 27 counties

Bond County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL

The radar

The Lincoln radar (KILX), 61 km from the middle of the area, began a volume at 05:04 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 00:00Z, 5.0 hours before the alert went out and 91 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 493 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 343 m²/s²
0-3 km storm-relative helicity: 702 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.9

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
Apr 15, 8:59 PM CDT	Mesoscale Discussion	SPC	Monroe	61 min
Apr 16, 12:00 AM CDT	Severe Thunderstorm Watch	SPC	Bond, Brown, Calhoun, Cass, Christian, DeWitt and 19 more	4 hr
Apr 16, 2:54 PM CDT	Mesoscale Discussion	SPC	Gallatin, Hardin, Johnson, Massac, Pope, Pulaski	96 min

Nearby

Mesoscale Discussions in Illinois, 2013 Every mesoscale discussion in 2013

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.