Alert archive / Montana / Mesoscale Discussions in 2007

Mesoscale Discussion 778

May 12, 200714 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at May 12, 2007, 5:07 PM MDT for 14 counties in Montana. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: May 12, 2007, 5:07 PM MDT (23:07 UTC)
Expired: May 12, 2007, 6:30 PM MDT
In force: 83 min
Issued by: the Storm Prediction Center

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

The radar

The Great Falls radar (KTFX), 29 km from the middle of the area, began a volume at 23:07 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, 11.1 hours before the alert went out and 49 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: 332 J/kg
Mixed-layer CIN: -159 J/kg
Mixed-layer LCL: 1399 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 33 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
May 12, 1:19 PM MDT	Mesoscale Discussion	SPC	Blaine, Broadwater, Cascade, Chouteau, Fergus, Golden Valley and 10 more	116 min
May 12, 2:11 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Broadwater, Cascade, Chouteau, Deer Lodge, Fergus and 14 more	7 hr

Nearby

Mesoscale Discussions in Montana, 2007 Every mesoscale discussion in 2007

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.