Alert archive / Missouri / Mesoscale Discussions in 2004

Mesoscale Discussion 1620

July 11, 200424 counties in Illinois; Atchison County, Doniphan County, Kansas; 34 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jul 11, 2004, 5:19 PM CDT for 24 counties in Illinois; Atchison County, Doniphan County, Kansas; 34 counties in Missouri. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Jul 11, 2004, 5:19 PM CDT (22:19 UTC)
Expired: Jul 11, 2004, 7:15 PM CDT
In force: 116 min
Issued by: the Storm Prediction Center

All 60 counties

Bond County, IL, Calhoun County, IL, Champaign County, IL, Christian County, IL, Clinton County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, McLean County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Atchison County, KS, Doniphan County, KS, Adair County, MO, Audrain County, MO, Boone County, MO, Buchanan County, MO, Caldwell County, MO, Callaway County, MO, Carroll County, MO, Chariton County, MO, City of Saint Louis, MO, Clay County, MO, Clinton County, MO, Cooper County, MO, DeKalb County, MO, Howard County, MO, Knox County, MO, Lafayette County, MO, Lincoln County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Montgomery County, MO, Pike County, MO, Platte County, MO, Ralls County, MO, Randolph County, MO, Ray County, MO, Saint Charles County, MO, Saint Louis County, MO, Saline County, MO, Schuyler County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 129 km from the middle of the area, began a volume at 22:19 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.

Severe Thunderstorm Watch 606Jul 11, 5:40 PM CDT

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.3 hours before the alert went out and 241 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: 339 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 706 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 35 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
Jul 11, 10:14 AM CDT	Mesoscale Discussion	SPC	Bureau, Carroll, DeKalb, DuPage, Ford, Fulton and 24 more	91 min
Jul 11, 11:40 AM CDT	Severe Thunderstorm Watch	SPC	Bureau, Carroll, Cass, Champaign, Cook, DeKalb and 40 more	6 hr
Jul 11, 3:00 PM CDT	Severe Thunderstorm Watch	SPC	Calhoun, Greene, Jersey, Macoupin, Morgan, Pike and 1 more	5 hr
Jul 11, 5:40 PM CDT	Severe Thunderstorm Watch	SPC	Champaign, Christian, Clark, Coles, Cumberland, DeWitt and 16 more	5 hr
Jul 10, 9:41 PM CDT	Mesoscale Discussion	SPC	Cheyenne, Decatur, Graham, Norton, Phillips, Rawlins and 4 more	3 hr
Jul 11, 10:33 AM CDT	Mesoscale Discussion	SPC	Atchison	117 min
Jul 11, 11:55 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Atchison, Gentry, Grundy, Harrison, Holt and 5 more	6 hr
Jul 11, 2:04 PM CDT	Mesoscale Discussion	SPC	Atchison	116 min

Nearby

Mesoscale Discussions in Missouri, 2004 Mesoscale Discussions in Illinois, 2004 Mesoscale Discussions in Kansas, 2004 Every mesoscale discussion in 2004

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.