Alert archive / Illinois / Mesoscale Discussions in 2018

Mesoscale Discussion 400

May 13, 201815 counties in Illinois

The Storm Prediction Center issued this mesoscale discussion at May 13, 2018, 3:43 PM CDT for 15 counties in Illinois. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 13, 2018, 3:43 PM CDT (20:43 UTC)
Expired
May 13, 2018, 5:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Fulton County, IL, Henderson County, IL, Knox County, IL, Livingston 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, Woodford County, IL

The radar

The Lincoln radar (KILX), 68 km from the middle of the area, began a volume at 20:43 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

Davenport, (KDVN), launched 12:00Z, 8.7 hours before the alert went out and 123 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 2018-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2018-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
647 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

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Nearby

Mesoscale Discussions in Illinois, 2018Every mesoscale discussion in 2018

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.