Alert archive / Illinois / Mesoscale Discussions in 2006

Mesoscale Discussion 701

April 30, 20065 states

The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2006, 11:20 AM CDT for 5 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Apr 30, 2006, 11:20 AM CDT (16:20 UTC)
Expired: Apr 30, 2006, 12:45 PM CDT
In force: 85 min
Issued by: the Storm Prediction Center

All 40 counties

Crittenden County, AR, Mississippi County, AR, Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton 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, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Marshall 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, Stoddard County, MO, Crockett County, TN, Dyer County, TN, Gibson County, TN, Haywood County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 50 km from the middle of the area, began a volume at 16:23 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 4.3 hours before the alert went out and 228 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: 20 J/kg
Mixed-layer CIN: -135 J/kg
Mixed-layer LCL: 1054 m above ground
0-6 km bulk shear: 72 kt
0-1 km storm-relative helicity: -36 m²/s²
0-3 km storm-relative helicity: 86 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 30, 10:30 AM CDT	Mesoscale Discussion	SPC	Baxter, Fulton, Marion	90 min
Apr 30, 11:52 AM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Clay, Cleburne, Craighead, Fulton and 16 more	7 hr
Apr 30, 1:04 PM CDT	Mesoscale Discussion	SPC	Randolph	86 min
Apr 30, 2:30 PM CDT	Mesoscale Discussion	SPC	Clay, Greene, Mississippi	2 hr
Apr 30, 3:05 PM CDT	Tornado Watch	SPC	Clay, Craighead, Greene, Lawrence, Mississippi, Poinsett and 1 more	6 hr
Apr 30, 5:25 PM CDT	Mesoscale Discussion	SPC	Clay, Craighead, Greene, Lawrence, Mississippi, Poinsett and 1 more	95 min

Nearby

Mesoscale Discussions in Illinois, 2006 Mesoscale Discussions in Tennessee, 2006 Mesoscale Discussions in Kentucky, 2006 Every mesoscale discussion in 2006

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.