Alert archive / Illinois / Mesoscale Discussions in 2017

Mesoscale Discussion 776

May 19, 201715 counties in Illinois

The Storm Prediction Center issued this mesoscale discussion at May 19, 2017, 6:30 AM CDT for 15 counties in Illinois. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: May 19, 2017, 6:30 AM CDT (11:30 UTC)
Expired: May 19, 2017, 8:00 AM CDT
In force: 90 min
Issued by: the Storm Prediction Center

Counties Bond County, IL, Clay County, IL, Clinton County, IL, Crawford County, IL, Cumberland County, IL, Effingham County, IL, Fayette County, IL, Jasper County, IL, Jefferson County, IL, Lawrence County, IL, Marion County, IL, Montgomery County, IL, Richland County, IL, Washington County, IL, Wayne County, IL

The radar

The Evansville,IN radar (KVWX), 119 km from the middle of the area, began a volume at 11:29 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, 11.5 hours before the alert went out and 149 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: 631 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 2069 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 30 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

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
May 19, 4:07 AM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more	113 min
May 19, 4:16 AM CDT	Severe Thunderstorm Watch	SPC	Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more	3 hr
May 19, 3:06 PM CDT	Tornado Watch	SPC	Calhoun	7 hr
May 19, 6:04 PM CDT	Mesoscale Discussion	SPC	Calhoun	86 min

Nearby

Mesoscale Discussions in Illinois, 2017 Every mesoscale discussion in 2017

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.