Alert archive / Illinois / Mesoscale Discussions in 2009

Mesoscale Discussion 997

June 8, 200910 counties in Illinois; Ballard County, McCracken County, Kentucky; 10 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jun 8, 2009, 9:35 PM CDT for 10 counties in Illinois; Ballard County, McCracken County, Kentucky; 10 counties in Missouri. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Jun 8, 2009, 9:35 PM CDT (02:35 UTC)
Expired: Jun 8, 2009, 10:30 PM CDT
In force: 55 min
Issued by: the Storm Prediction Center

All 22 counties

Alexander County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Williamson County, IL, Ballard County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Madison County, MO, Mississippi County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 96 km from the middle of the area, began a volume at 02:38 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, 2.6 hours before the alert went out and 346 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: 1379 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 1240 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 133 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.1

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
Jun 8, 7:18 PM CDT	Mesoscale Discussion	SPC	Alexander, Franklin, Hamilton, Jackson, Johnson, Perry and 6 more	57 min
Jun 9, 3:04 PM CDT	Mesoscale Discussion	SPC	Alexander, Jackson, Johnson, Massac, Pulaski, Union	86 min
Jun 9, 3:41 PM CDT	Severe Thunderstorm Watch	SPC	Alexander, Johnson, Massac, Pulaski, Union	7 hr
Jun 9, 12:38 PM CDT	Mesoscale Discussion	SPC	Boyd, Greenup, Lewis	97 min
Jun 9, 1:07 PM CDT	Severe Thunderstorm Watch	SPC	Boyd, Carter, Greenup, Lawrence	7 hr
Jun 9, 8:40 AM CDT	Mesoscale Discussion	SPC	Bates, Cass	65 min
Jun 9, 9:02 AM CDT	Severe Thunderstorm Watch	SPC	Barton, Bates, Benton, Camden, Cass, Cedar and 12 more	6 hr
Jun 9, 11:11 AM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Camden, Cass, Cedar and 18 more	94 min
Jun 9, 12:59 PM CDT	Mesoscale Discussion	SPC	Bates, Benton, Camden, Cedar, Dallas, Henry and 9 more	91 min
Jun 9, 1:31 PM CDT	Tornado Watch	SPC	Barry, Barton, Benton, Camden, Cedar, Christian and 28 more	8 hr
Jun 9, 6:22 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Carter, Cedar, Christian, Dade and 19 more	53 min

Nearby

Mesoscale Discussions in Illinois, 2009 Mesoscale Discussions in Missouri, 2009 Mesoscale Discussions in Kentucky, 2009 Every mesoscale discussion in 2009

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.