Alert archive / Illinois / Mesoscale Discussions in 2007

Mesoscale Discussion 1502

July 16, 200727 counties in Illinois; 10 counties in Iowa; Lafayette County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 16, 2007, 9:50 PM CDT for 27 counties in Illinois; 10 counties in Iowa; Lafayette County, Wisconsin. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Jul 16, 2007, 9:50 PM CDT (02:50 UTC)
Expired: Jul 16, 2007, 11:15 PM CDT
In force: 85 min
Issued by: the Storm Prediction Center

All 38 counties

Cedar County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Muscatine County, IA, Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, McHenry County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Woodford County, IL, Lafayette County, WI

The radar

The Quad Cities radar (KDVN), 58 km from the middle of the area, began a volume at 02:53 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 00:00Z, 2.8 hours before the alert went out and 52 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: 405 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 1277 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 211 m²/s²
0-3 km storm-relative helicity: 243 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.4

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
Jul 17, 2:53 AM CDT	Mesoscale Discussion	SPC	Rock Island	82 min
Jul 17, 4:37 AM CDT	Severe Thunderstorm Watch	SPC	Henry, Mercer, Rock Island, Whiteside	3 hr
Jul 17, 6:58 AM CDT	Mesoscale Discussion	SPC	Bureau, Cass, DeWitt, Fulton, Grundy, Henderson and 17 more	92 min
Jul 17, 10:52 AM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Clark, Clay, Clinton, Coles and 32 more	83 min
Jul 17, 1:25 PM CDT	Severe Thunderstorm Watch	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 12 more	6 hr
Jul 17, 1:33 PM CDT	Mesoscale Discussion	SPC	Bureau, Carroll, Henry, Jo Daviess, Knox, Mercer and 5 more	117 min
Jul 17, 3:34 PM CDT	Mesoscale Discussion	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 12 more	86 min
Jul 16, 7:39 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Boone, Bremer, Buchanan and 50 more	96 min
Jul 17, 5:55 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 19 more	95 min

Nearby

Mesoscale Discussions in Illinois, 2007 Mesoscale Discussions in Iowa, 2007 Mesoscale Discussions in Wisconsin, 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.