Alert archive / Montana / Mesoscale Discussions in 2003

Mesoscale Discussion 1427

June 20, 200315 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2003, 2:39 PM MDT for 15 counties in Montana. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Jun 20, 2003, 2:39 PM MDT (20:39 UTC)
Expired: Jun 20, 2003, 4:15 PM MDT
In force: 96 min
Issued by: the Storm Prediction Center

Counties Blaine County, MT, Broadwater County, MT, Cascade County, MT, Chouteau County, MT, Fergus County, MT, Gallatin County, MT, Golden Valley County, MT, Hill County, MT, Judith Basin County, MT, Liberty County, MT, Meagher County, MT, Park County, MT, Stillwater County, MT, Sweet Grass County, MT, Wheatland County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.7 hours before the alert went out and 57 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: 29 J/kg
Mixed-layer CIN: -308 J/kg
Mixed-layer LCL: 1255 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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
Jun 20, 11:36 AM MDT	Mesoscale Discussion	SPC	Blaine, Broadwater, Carbon, Cascade, Chouteau, Fergus and 17 more	114 min
Jun 20, 12:05 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Broadwater, Carbon, Cascade, Chouteau, Fergus and 12 more	8 hr
Jun 20, 3:25 PM MDT	Mesoscale Discussion	SPC	Big Horn, Carter, Custer, Daniels, Dawson, Fallon and 15 more	65 min
Jun 20, 3:30 PM MDT	Severe Thunderstorm Watch	SPC	Big Horn, Carter, Custer, Daniels, Dawson, Fallon and 15 more	8 hr
Jun 20, 4:43 PM MDT	Mesoscale Discussion	SPC	Big Horn, Blaine, Carter, Custer, Daniels, Dawson and 16 more	62 min

Nearby

Mesoscale Discussions in Montana, 2003 Every mesoscale discussion in 2003

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.