Alert archive / Illinois / Mesoscale Discussions in 2015

Mesoscale Discussion 1789

September 10, 201528 counties in Illinois; Lake County, Newton County, Indiana

The Storm Prediction Center issued this mesoscale discussion at Sep 10, 2015, 12:47 PM CDT for 28 counties in Illinois; Lake County, Newton County, Indiana. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Sep 10, 2015, 12:47 PM CDT (17:47 UTC)
Expired: Sep 10, 2015, 1:45 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 30 counties

Bureau County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Henderson County, IL, Henry County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Mercer County, IL, Peoria County, IL, Putnam County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Will County, IL, Woodford County, IL, Lake County, IN, Newton County, IN

The radar

The Chicago radar (KLOT), 80 km from the middle of the area, began a volume at 17:48 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, 5.8 hours before the alert went out and 106 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: 2 J/kg
Mixed-layer CIN: -179 J/kg
Mixed-layer LCL: 1050 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 24 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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Nearby

Mesoscale Discussions in Illinois, 2015 Mesoscale Discussions in Indiana, 2015 Every mesoscale discussion in 2015

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.