Alert archive / Kansas / Mesoscale Discussions in 2011

Mesoscale Discussion 836

May 21, 201124 counties in Kansas; 10 counties in Missouri; 8 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 21, 2011, 2:33 PM CDT for 24 counties in Kansas; 10 counties in Missouri; 8 counties in Nebraska. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: May 21, 2011, 2:33 PM CDT (19:33 UTC)
Expired: May 21, 2011, 4:00 PM CDT
In force: 87 min
Issued by: the Storm Prediction Center

All 42 counties

Atchison County, KS, Brown County, KS, Clay County, KS, Cloud County, KS, Doniphan County, KS, Geary County, KS, Jackson County, KS, Jefferson County, KS, Jewell County, KS, Leavenworth County, KS, Lincoln County, KS, Marshall County, KS, Mitchell County, KS, Nemaha County, KS, Osborne County, KS, Ottawa County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Shawnee County, KS, Smith County, KS, Wabaunsee County, KS, Washington County, KS, Wyandotte County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Clay County, MO, Clinton County, MO, DeKalb County, MO, Gentry County, MO, Holt County, MO, Nodaway County, MO, Platte County, MO, Gage County, NE, Jefferson County, NE, Johnson County, NE, Nemaha County, NE, Nuckolls County, NE, Pawnee County, NE, Richardson County, NE, Thayer County, NE

The radar

The Topeka radar (KTWX), 63 km from the middle of the area, began a volume at 19:34 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.

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 7.6 hours before the alert went out and 90 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: 480 J/kg
Mixed-layer CIN: -193 J/kg
Mixed-layer LCL: 716 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 64 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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 21, 3:41 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Brown, Chase, Clay, Cloud, Coffey and 27 more	9 hr
May 21, 5:25 PM CDT	Mesoscale Discussion	SPC	Doniphan	65 min
May 21, 5:34 PM CDT	Severe Thunderstorm Watch	SPC	Atchison, Doniphan, Johnson, Leavenworth, Miami, Wyandotte	7 hr
May 21, 12:51 PM CDT	Mesoscale Discussion	SPC	Atchison	114 min
May 21, 6:07 PM CDT	Mesoscale Discussion	SPC	Atchison	53 min
May 21, 2:25 PM CDT	Severe Thunderstorm Watch	SPC	Burt, Butler, Cass, Cuming, Dakota, Dodge and 15 more	10 hr

Nearby

Mesoscale Discussions in Kansas, 2011 Mesoscale Discussions in Missouri, 2011 Mesoscale Discussions in Nebraska, 2011 Every mesoscale discussion in 2011

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.