Alert archive / North Dakota / Mesoscale Discussions in 2006

Mesoscale Discussion 1797

August 11, 20064 states

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2006, 1:18 PM MDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: Aug 11, 2006, 1:18 PM MDT (19:18 UTC)
Expired: Aug 11, 2006, 3:15 PM MDT
In force: 117 min
Issued by: the Storm Prediction Center

All 49 counties

Dawson County, MT, Fallon County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Wibaux County, MT, Adams County, ND, Billings County, ND, Bowman County, ND, Burke County, ND, Divide County, ND, Dunn County, ND, Golden Valley County, ND, Grant County, ND, Hettinger County, ND, McKenzie County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Mountrail County, ND, Oliver County, ND, Renville County, ND, Sioux County, ND, Slope County, ND, Stark County, ND, Ward County, ND, Williams County, ND, Box Butte County, NE, Cherry County, NE, Dawes County, NE, Sheridan County, NE, Bennett County, SD, Butte County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Todd County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 138 km from the middle of the area, began a volume at 19:23 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 710Aug 11, 1:50 PM MDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 7.3 hours before the alert went out and 143 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: 1304 J/kg
Mixed-layer CIN: -264 J/kg
Mixed-layer LCL: 1423 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: -10 m²/s²
0-3 km storm-relative helicity: 59 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
Aug 10, 6:07 PM MDT	Severe Thunderstorm Watch	SPC	Boyd, Brown, Cherry, Holt, Keya Paha, Rock	6 hr
Aug 10, 8:29 PM MDT	Mesoscale Discussion	SPC	Antelope, Blaine, Boone, Boyd, Brown, Cedar and 25 more	91 min
Aug 10, 9:30 PM MDT	Severe Thunderstorm Watch	SPC	Antelope, Blaine, Boone, Burt, Cedar, Colfax and 21 more	6 hr
Aug 11, 1:07 AM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Burt, Colfax, Cuming, Dakota and 12 more	53 min
Aug 11, 1:46 PM MDT	Severe Thunderstorm Watch	SPC	Cherry, Sheridan	8 hr
Aug 11, 4:20 PM MDT	Mesoscale Discussion	SPC	Boyd, Keya Paha	85 min

Nearby

Mesoscale Discussions in North Dakota, 2006 Mesoscale Discussions in South Dakota, 2006 Mesoscale Discussions in Montana, 2006 Every mesoscale discussion in 2006

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.