Alert archive / Illinois / Mesoscale Discussions in 2014

Mesoscale Discussion 398

April 24, 201410 counties in Illinois; City of Saint Louis, Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2014, 6:12 PM CDT for 10 counties in Illinois; City of Saint Louis, Missouri. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: Apr 24, 2014, 6:12 PM CDT (23:12 UTC)
Expired: Apr 24, 2014, 7:45 PM CDT
In force: 93 min
Issued by: the Storm Prediction Center

Counties Cass County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Saint Clair County, IL, Sangamon County, IL, City of Saint Louis, MO

The radar

The St Louis radar (KLSX), 68 km from the middle of the area, began a volume at 23:15 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, 11.2 hours before the alert went out and 173 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2131 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 200 m²/s²
0-3 km storm-relative helicity: 341 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
Apr 24, 2:21 PM CDT	Severe Thunderstorm Watch	SPC	Calhoun, Greene, Jersey, Macoupin, Madison, Monroe and 2 more	6 hr
Apr 24, 5:50 PM CDT	Mesoscale Discussion	SPC	Massac	85 min
Apr 24, 12:42 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Bates, Benton, Camden, Cedar and 31 more	93 min
Apr 24, 2:38 PM CDT	Severe Thunderstorm Watch	SPC	Dunklin, Pemiscot	9 hr
Apr 24, 3:47 PM CDT	Mesoscale Discussion	SPC	Barry, Benton, Callaway, Camden, Cedar, Christian and 30 more	88 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.