Alert archive / South Dakota / Mesoscale Discussions in 2005

Mesoscale Discussion 1815

July 21, 20057 counties in North Dakota; 11 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2005, 4:00 PM MDT for 7 counties in North Dakota; 11 counties in South Dakota. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: Jul 21, 2005, 4:00 PM MDT (22:00 UTC)
Expired: Jul 21, 2005, 5:30 PM MDT
In force: 90 min
Issued by: the Storm Prediction Center

Counties Adams County, ND, Bowman County, ND, Grant County, ND, Hettinger County, ND, Sioux County, ND, Slope County, ND, Stark County, ND, Butte County, SD, Corson County, SD, Custer County, SD, Fall River County, SD, Harding County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 111 km from the middle of the area, began a volume at 22:02 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 10.0 hours before the alert went out and 245 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1362 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 145 m²/s²
0-3 km storm-relative helicity: 229 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 21, 11:47 AM MDT	Mesoscale Discussion	SPC	Adams, Burleigh, Dunn, Grant, Hettinger, McLean and 5 more	88 min
Jul 21, 4:35 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Burleigh, Emmons, Grant, Hettinger, Kidder and 6 more	6 hr
Jul 20, 8:46 PM MDT	Mesoscale Discussion	SPC	Gregory	89 min
Jul 20, 9:10 PM MDT	Severe Thunderstorm Watch	SPC	Bon Homme, Clay, Union	4 hr

Nearby

Mesoscale Discussions in South Dakota, 2005 Mesoscale Discussions in North Dakota, 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.