Alert archive / Montana / Mesoscale Discussions in 2012

Mesoscale Discussion 1687

August 2, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Aug 2, 2012, 6:10 PM MDT for 4 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Aug 2, 2012, 6:10 PM MDT (00:10 UTC)
Expired: Aug 2, 2012, 7:45 PM MDT
In force: 95 min
Issued by: the Storm Prediction Center

All 29 counties

Carter County, MT, Custer County, MT, Daniels County, MT, Dawson County, MT, Fallon County, MT, McCone County, MT, Powder River County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Wibaux County, MT, Adams County, ND, Billings County, ND, Bowman County, ND, Divide County, ND, Dunn County, ND, Golden Valley County, ND, Hettinger County, ND, McKenzie County, ND, Slope County, ND, Stark County, ND, Williams County, ND, Butte County, SD, Harding County, SD, Lawrence County, SD, Meade County, SD, Perkins County, SD, Crook County, WY

The radar

The Glasgow radar (KGGW), 246 km from the middle of the area, began a volume at 00:13 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 00:00Z, 0.2 hours before the alert went out and 265 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: 72 J/kg
Mixed-layer CIN: -236 J/kg
Mixed-layer LCL: 2074 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 75 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 3, 12:31 PM MDT	Mesoscale Discussion	SPC	Barnes, Cass, Cavalier, Dickey, Eddy, Emmons and 16 more	59 min
Aug 3, 1:14 PM MDT	Severe Thunderstorm Watch	SPC	Barnes, Cass, Dickey, Eddy, Emmons, Foster and 14 more	7 hr
Aug 3, 5:19 PM MDT	Mesoscale Discussion	SPC	Barnes, Cass, Dickey, Eddy, Foster, Grand Forks and 9 more	86 min
Aug 3, 12:02 AM MDT	Mesoscale Discussion	SPC	Gregory	88 min

Nearby

Mesoscale Discussions in Montana, 2012 Mesoscale Discussions in North Dakota, 2012 Mesoscale Discussions in South Dakota, 2012 Every mesoscale discussion in 2012

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.