Alert archive / Montana / Mesoscale Discussions in 2014

Mesoscale Discussion 1559

August 15, 201412 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Aug 15, 2014, 2:49 PM MDT for 12 counties in Montana. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: Aug 15, 2014, 2:49 PM MDT (20:49 UTC)
Expired: Aug 15, 2014, 3:45 PM MDT
In force: 56 min
Issued by: the Storm Prediction Center

Counties Broadwater County, MT, Cascade County, MT, Chouteau County, MT, Hill County, MT, Jefferson County, MT, Judith Basin County, MT, Lewis and Clark County, MT, Liberty County, MT, Meagher County, MT, Pondera County, MT, Teton County, MT, Toole County, MT

The radar

The Great Falls radar (KTFX), 49 km from the middle of the area, began a volume at 20:51 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

Great_falls, MT (KTFX), launched 12:00Z, 8.8 hours before the alert went out and 98 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: 235 J/kg
Mixed-layer CIN: -96 J/kg
Mixed-layer LCL: 867 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 42 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

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 15, 12:11 PM MDT	Mesoscale Discussion	SPC	Broadwater, Cascade, Chouteau, Gallatin, Jefferson, Judith Basin and 11 more	64 min
Aug 15, 12:26 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Broadwater, Cascade, Chouteau, Fergus, Glacier and 9 more	8 hr
Aug 15, 5:34 PM MDT	Mesoscale Discussion	SPC	Blaine, Chouteau, Fergus, Hill, Liberty, Toole	116 min

Nearby

Mesoscale Discussions in Montana, 2014 Every mesoscale discussion in 2014

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.