Alert archive / North Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 2070

August 27, 20115 counties in Montana; 9 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2011, 6:30 PM MDT for 5 counties in Montana; 9 counties in North Dakota. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: Aug 27, 2011, 6:30 PM MDT (00:30 UTC)
Expired: Aug 27, 2011, 8:00 PM MDT
In force: 90 min
Issued by: the Storm Prediction Center

Counties Daniels County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Valley County, MT, Burke County, ND, Divide County, ND, Dunn County, ND, McKenzie County, ND, McLean County, ND, Mountrail County, ND, Renville County, ND, Ward County, ND, Williams County, ND

The radar

The Glasgow radar (KGGW), 198 km from the middle of the area, began a volume at 00:34 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 nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.5 hours before the alert went out and 196 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: 170 J/kg
Mixed-layer CIN: -99 J/kg
Mixed-layer LCL: 2762 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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 28, 1:09 AM MDT	Mesoscale Discussion	SPC	Burleigh, Dickey, Emmons, Grant, Hettinger, Kidder and 8 more	66 min

Nearby

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