Alert archive / North Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 1871

August 5, 201113 counties in North Dakota; 10 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 5, 2011, 10:08 PM CDT for 13 counties in North Dakota; 10 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 5, 2011, 10:08 PM CDT (03:08 UTC)
Expired: Aug 6, 2011, 12:15 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 23 counties

Barnes County, ND, Cass County, ND, Dickey County, ND, Foster County, ND, Griggs County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Ransom County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Brown County, SD, Buffalo County, SD, Edmunds County, SD, Faulk County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Lyman County, SD, McPherson County, SD, Spink County, SD

The radar

The Aberdeen radar (KABR), 49 km from the middle of the area, began a volume at 03:09 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

Aberdeen, SD (KABR), launched 00:00Z, 3.1 hours before the alert went out and 73 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: 524 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 1596 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: -18 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
Aug 5, 7:32 PM CDT	Severe Thunderstorm Watch	SPC	Barnes, Cass, Dickey, Foster, Griggs, Kidder and 9 more	4 hr
Aug 5, 7:32 PM CDT	Mesoscale Discussion	SPC	Butte	88 min
Aug 6, 2:58 PM CDT	Mesoscale Discussion	SPC	Clay, Union	3 hr
Aug 6, 6:14 PM CDT	Mesoscale Discussion	SPC	Clark, Codington, Day, Deuel, Grant, Hamlin and 2 more	2 hr

Nearby

Mesoscale Discussions in North Dakota, 2011 Mesoscale Discussions in South Dakota, 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.