Alert archive / Illinois / Mesoscale Discussions in 2007

Mesoscale Discussion 304

March 21, 200713 counties in Illinois; Clinton County, Jackson County, Scott County, Iowa; 5 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Mar 21, 2007, 1:26 PM CDT for 13 counties in Illinois; Clinton County, Jackson County, Scott County, Iowa; 5 counties in Wisconsin. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Mar 21, 2007, 1:26 PM CDT (18:26 UTC)
Expired: Mar 21, 2007, 2:30 PM CDT
In force: 64 min
Issued by: the Storm Prediction Center

All 21 counties

Clinton County, IA, Jackson County, IA, Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Henry County, IL, Jo Daviess County, IL, Lee County, IL, Mercer County, IL, Ogle County, IL, Rock Island County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Dane County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Rock County, WI

The radar

The Quad Cities radar (KDVN), 70 km from the middle of the area, began a volume at 18:29 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

Davenport, (KDVN), launched 12:00Z, 6.4 hours before the alert went out and 65 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: 699 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 261 m²/s²
0-3 km storm-relative helicity: 275 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
Mar 21, 9:44 AM CDT	Mesoscale Discussion	SPC	Adams, Hancock, Henderson	2 hr
Mar 21, 12:30 PM CDT	Mesoscale Discussion	SPC	Boone, Carroll, Henry, Jo Daviess, Knox, Lee and 7 more	90 min
Mar 21, 5:15 PM CDT	Mesoscale Discussion	SPC	Boone, Cook, DuPage, Kane, Lake, McHenry and 1 more	2 hr
Mar 21, 6:37 AM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Boone, Butler and 36 more	113 min
Mar 21, 10:24 AM CDT	Severe Thunderstorm Watch	SPC	Appanoose, Benton, Black Hawk, Buchanan, Cedar, Clarke and 31 more	5 hr
Mar 21, 12:58 PM CDT	Mesoscale Discussion	SPC	Appanoose, Davis, Lee, Van Buren	62 min
Mar 21, 4:57 PM CDT	Mesoscale Discussion	SPC	Crawford, Fremont, Harrison, Ida, Mills, Monona and 3 more	63 min
Mar 21, 5:15 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 34 more	7 hr

Nearby

Mesoscale Discussions in Illinois, 2007 Mesoscale Discussions in Wisconsin, 2007 Mesoscale Discussions in Iowa, 2007 Every mesoscale discussion in 2007

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.