Alert archive / Illinois / Mesoscale Discussions in 2006

Mesoscale Discussion 706

April 30, 20064 states

The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2006, 7:45 PM CDT for 4 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: Apr 30, 2006, 7:45 PM CDT (00:45 UTC)
Expired: Apr 30, 2006, 8:45 PM CDT
In force: 60 min
Issued by: the Storm Prediction Center

All 26 counties

Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Wayne County, IL, Williamson County, IL, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Hickman County, KY, Livingston County, KY, McCracken County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Lake County, TN, Obion County, TN

The radar

The Paducah radar (KPAH), 36 km from the middle of the area, began a volume at 00:49 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, 0.8 hours before the alert went out and 258 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: 50 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 1980 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 89 m²/s²
0-3 km storm-relative helicity: 118 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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
May 1, 2:22 PM CDT	Mesoscale Discussion	SPC	Alexander, Bond, Clinton, Franklin, Jackson, Johnson and 11 more	53 min
May 1, 5:17 PM CDT	Tornado Watch	SPC	Alexander, Bond, Calhoun, Clinton, Fayette, Greene and 13 more	7 hr
May 1, 6:59 PM CDT	Mesoscale Discussion	SPC	Alexander, Bond, Calhoun, Clinton, Fayette, Greene and 11 more	91 min
Apr 30, 9:40 PM CDT	Mesoscale Discussion	SPC	McDonald	95 min
May 1, 4:17 PM CDT	Mesoscale Discussion	SPC	Barry, Christian, Greene, Lawrence, McDonald, Newton and 2 more	118 min

Nearby

Mesoscale Discussions in Illinois, 2006 Mesoscale Discussions in Kentucky, 2006 Mesoscale Discussions in Missouri, 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.