Alert archive / Montana / Mesoscale Discussions in 2003

Mesoscale Discussion 1422

June 20, 20037 counties in Idaho; 23 counties in Montana; Park County, Teton County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2003, 11:36 AM MDT for 7 counties in Idaho; 23 counties in Montana; Park County, Teton County, Wyoming. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: Jun 20, 2003, 11:36 AM MDT (17:36 UTC)
Expired: Jun 20, 2003, 1:30 PM MDT
In force: 114 min
Issued by: the Storm Prediction Center

All 32 counties

Bingham County, ID, Bonneville County, ID, Clark County, ID, Fremont County, ID, Jefferson County, ID, Madison County, ID, Teton County, ID, Blaine County, MT, Broadwater County, MT, Carbon County, MT, Cascade County, MT, Chouteau County, MT, Fergus County, MT, Gallatin County, MT, Golden Valley County, MT, Hill County, MT, Jefferson County, MT, Judith Basin County, MT, Liberty County, MT, Madison County, MT, Meagher County, MT, Musselshell County, MT, Park County, MT, Pondera County, MT, Stillwater County, MT, Sweet Grass County, MT, Teton County, MT, Toole County, MT, Wheatland County, MT, Yellowstone County, MT, Park County, WY, Teton County, WY

The radar

The Billings radar (KBLX), 146 km from the middle of the area, began a volume at 17:35 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.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 5.6 hours before the alert went out and 168 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, 12:05 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Broadwater, Carbon, Cascade, Chouteau, Fergus and 12 more	8 hr
Jun 20, 2:39 PM MDT	Mesoscale Discussion	SPC	Blaine, Broadwater, Cascade, Chouteau, Fergus, Gallatin and 9 more	96 min
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
Jun 20, 12:17 PM MDT	Mesoscale Discussion	SPC	Fremont, Hot Springs, Lincoln, Sublette, Sweetwater, Uinta	118 min
Jun 20, 1:41 PM MDT	Mesoscale Discussion	SPC	Albany, Goshen, Laramie, Platte	2 hr
Jun 20, 2:25 PM MDT	Severe Thunderstorm Watch	SPC	Campbell, Crook, Goshen, Laramie, Niobrara, Platte and 1 more	7 hr
Jun 20, 5:45 PM MDT	Mesoscale Discussion	SPC	Crook, Weston	60 min

Nearby

Mesoscale Discussions in Montana, 2003 Mesoscale Discussions in Idaho, 2003 Mesoscale Discussions in Wyoming, 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; radar from the NEXRAD Level II archive.