Alert archive / Montana / Mesoscale Discussions in 2016

Mesoscale Discussion 1501

August 9, 201614 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Aug 9, 2016, 2:19 PM MDT for 14 counties in Montana. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Aug 9, 2016, 2:19 PM MDT (20:19 UTC)
Expired: Aug 9, 2016, 4:15 PM MDT
In force: 116 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Broadwater County, MT, Cascade County, MT, Chouteau County, MT, Deer Lodge County, MT, Granite County, MT, Jefferson County, MT, Judith Basin County, MT, Lewis and Clark County, MT, Liberty County, MT, Meagher County, MT, Pondera County, MT, Powell County, MT, Silver Bow County, MT, Teton County, MT

The radar

The Great Falls radar (KTFX), 20 km from the middle of the area, began a volume at 20:21 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 436Aug 9, 4:50 PM MDT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.3 hours before the alert went out and 71 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: 195 J/kg
Mixed-layer CIN: -253 J/kg
Mixed-layer LCL: 1229 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 59 m²/s²
0-3 km storm-relative helicity: 288 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 9, 3:51 PM MDT	Mesoscale Discussion	SPC	Carter, Custer, Fallon, Powder River	114 min
Aug 9, 4:16 PM MDT	Severe Thunderstorm Watch	SPC	Carter, Custer, Fallon, Powder River	7 hr
Aug 9, 4:53 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Cascade, Chouteau, Fergus, Garfield, Glacier and 12 more	7 hr
Aug 9, 5:35 PM MDT	Mesoscale Discussion	SPC	Blaine, Broadwater, Cascade, Chouteau, Fergus, Garfield and 14 more	85 min

Nearby

Mesoscale Discussions in Montana, 2016 Every mesoscale discussion in 2016

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.