Alert archive / Illinois / Mesoscale Discussions in 2009

Mesoscale Discussion 97

February 11, 20095 states

The Storm Prediction Center issued this mesoscale discussion at Feb 11, 2009, 5:26 AM CST for 5 states. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Feb 11, 2009, 5:26 AM CST (11:26 UTC)
Expired: Feb 11, 2009, 6:30 AM CST
In force: 64 min
Issued by: the Storm Prediction Center

All 27 counties

Mississippi County, AR, Alexander County, IL, Franklin 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, Carlisle County, KY, Fulton County, KY, Hickman County, KY, McCracken County, KY, Cape Girardeau County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Dyer County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Tipton County, TN

The radar

The Paducah radar (KPAH), 60 km from the middle of the area, began a volume at 11:27 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

Little Rock, AR (KLZK), launched 00:00Z, 11.4 hours before the alert went out and 236 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: 632 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 645 m above ground
0-6 km bulk shear: 71 kt
0-1 km storm-relative helicity: 211 m²/s²
0-3 km storm-relative helicity: 244 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 3.9

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
Feb 10, 6:13 PM CST	Mesoscale Discussion	SPC	Crawford, Washington	92 min
Feb 10, 8:34 PM CST	Mesoscale Discussion	SPC	Conway, Crawford, Faulkner, Franklin, Garland, Hempstead and 19 more	86 min
Feb 10, 9:30 PM CST	Tornado Watch	SPC	Baxter, Benton, Boone, Carroll, Clark, Cleburne and 42 more	7 hr
Feb 10, 11:13 PM CST	Mesoscale Discussion	SPC	Baxter, Boone, Cleburne, Conway, Faulkner, Fulton and 18 more	92 min
Feb 10, 11:45 PM CST	Tornado Watch	SPC	Arkansas, Clay, Craighead, Crittenden, Cross, Greene and 12 more	6 hr
Feb 11, 12:37 AM CST	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Desha and 3 more	53 min
Feb 11, 1:04 AM CST	Tornado Watch	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Desha and 3 more	5 hr
Feb 11, 2:30 AM CST	Mesoscale Discussion	SPC	Arkansas, Clay, Craighead, Crittenden, Cross, Fulton and 18 more	90 min
Feb 11, 4:01 AM CST	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Columbia and 6 more	89 min
Feb 11, 10:02 AM CST	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Bell and 81 more	88 min
Feb 11, 10:38 AM CST	Tornado Watch	SPC	Adair, Allen, Anderson, Barren, Boone, Bourbon and 58 more	6 hr
Feb 11, 12:35 PM CST	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Bell and 84 more	85 min
Feb 11, 12:59 PM CST	Tornado Watch	SPC	Bath, Bell, Boyd, Breathitt, Carter, Clay and 32 more	7 hr
Feb 11, 3:34 PM CST	Mesoscale Discussion	SPC	Bell, Boyd, Breathitt, Carter, Clay, Elliott and 19 more	86 min
Feb 11, 11:10 AM CST	Tornado Watch	SPC	Bledsoe, Bradley, Franklin, Hamilton, Lincoln, McMinn and 6 more	6 hr
Feb 11, 1:29 PM CST	Mesoscale Discussion	SPC	Bradley, Franklin, Hamilton, Marion, Polk	2 hr

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.