Alert archive / North Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 853

May 21, 200724 counties in North Dakota; 15 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 21, 2007, 5:17 PM MDT for 24 counties in North Dakota; 15 counties in South Dakota. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: May 21, 2007, 5:17 PM MDT (23:17 UTC)
Expired: May 21, 2007, 6:45 PM MDT
In force: 88 min
Issued by: the Storm Prediction Center

All 39 counties

Adams County, ND, Benson County, ND, Bottineau County, ND, Burleigh County, ND, Dunn County, ND, Emmons County, ND, Grant County, ND, Hettinger County, ND, Kidder County, ND, Logan County, ND, McHenry County, ND, McIntosh County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Oliver County, ND, Pierce County, ND, Renville County, ND, Sheridan County, ND, Sioux County, ND, Stark County, ND, Towner County, ND, Ward County, ND, Wells County, ND, Butte County, SD, Campbell County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Bismarck radar (KBIS), 64 km from the middle of the area, began a volume at 23:18 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.3 hours before the alert went out and 66 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: 124 J/kg
Mixed-layer CIN: -413 J/kg
Mixed-layer LCL: 1282 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 231 m²/s²
0-3 km storm-relative helicity: 150 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 21, 2:59 AM MDT	Mesoscale Discussion	SPC	Barnes, Benson, Bottineau, Burke, Cass, Cavalier and 20 more	91 min
May 21, 12:22 PM MDT	Mesoscale Discussion	SPC	Adams, Benson, Bottineau, Bowman, Burleigh, Dunn and 20 more	83 min
May 21, 1:11 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Benson, Billings, Bottineau, Bowman, Burleigh and 28 more	9 hr
May 20, 6:48 PM MDT	Mesoscale Discussion	SPC	Butte, Lawrence	87 min
May 21, 12:07 PM MDT	Mesoscale Discussion	SPC	Roberts	83 min
May 21, 1:34 PM MDT	Mesoscale Discussion	SPC	Campbell, Corson, Dewey, Haakon, Hughes, Jackson and 13 more	86 min
May 21, 1:52 PM MDT	Severe Thunderstorm Watch	SPC	Bennett, Butte, Campbell, Corson, Custer, Dewey and 18 more	8 hr

Nearby

Mesoscale Discussions in North Dakota, 2007 Mesoscale Discussions in South Dakota, 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.