Alert archive / Missouri / Mesoscale Discussions in 2005

Mesoscale Discussion 861

May 13, 20054 counties in Illinois; 21 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 13, 2005, 2:41 PM CDT for 4 counties in Illinois; 21 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 13, 2005, 2:41 PM CDT (19:41 UTC)
Expired: May 13, 2005, 4:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 25 counties

Calhoun County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Camden County, MO, City of Saint Louis, MO, Crawford County, MO, Dade County, MO, Dallas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Jasper County, MO, Laclede County, MO, Lawrence County, MO, Maries County, MO, Miller County, MO, Osage County, MO, Phelps County, MO, Polk County, MO, Pulaski County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO, Webster County, MO

The radar

The St Louis radar (KLSX), 109 km from the middle of the area, began a volume at 19:43 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 271May 13, 5:05 PM CDT

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 7.7 hours before the alert went out and 346 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: 27 J/kg
Mixed-layer CIN: -226 J/kg
Mixed-layer LCL: 987 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 294 m²/s²
0-3 km storm-relative helicity: 145 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
May 12, 10:00 PM CDT	Mesoscale Discussion	SPC	Calhoun, Pike	90 min
May 12, 10:40 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 20 more	6 hr
May 13, 12:20 PM CDT	Mesoscale Discussion	SPC	Cook, DeWitt, DuPage, Ford, Grundy, Iroquois and 13 more	85 min
May 13, 12:41 PM CDT	Mesoscale Discussion	SPC	Alexander, Edwards, Gallatin, Hamilton, Hardin, Johnson and 7 more	2 hr
May 13, 12:50 PM CDT	Severe Thunderstorm Watch	SPC	Clark, Clay, Coles, Crawford, Cumberland, Douglas and 6 more	7 hr
May 13, 1:20 PM CDT	Severe Thunderstorm Watch	SPC	Gallatin, Hardin, Lawrence, Massac, Pope, Saline and 2 more	7 hr
May 13, 4:47 PM CDT	Mesoscale Discussion	SPC	Clark, Clay, Coles, Crawford, Cumberland, Douglas and 12 more	88 min
May 12, 8:26 PM CDT	Mesoscale Discussion	SPC	Buchanan, Cass, Clay, Jackson, Platte	34 min
May 13, 5:05 PM CDT	Severe Thunderstorm Watch	SPC	Barry, Barton, Camden, Cedar, Christian, Dade and 15 more	7 hr

Nearby

Mesoscale Discussions in Missouri, 2005 Mesoscale Discussions in Illinois, 2005 Every mesoscale discussion in 2005

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.