Alert archive / Montana / Mesoscale Discussions in 2003

Mesoscale Discussion 1433

June 20, 200322 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2003, 4:43 PM MDT for 22 counties in Montana. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Jun 20, 2003, 4:43 PM MDT (22:43 UTC)
Expired: Jun 20, 2003, 5:45 PM MDT
In force: 62 min
Issued by: the Storm Prediction Center

All 22 counties

Big Horn County, MT, Blaine County, MT, Carter County, MT, Custer County, MT, Daniels County, MT, Dawson County, MT, Fallon County, MT, Garfield County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Powder River County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Rosebud County, MT, Sheridan County, MT, Treasure County, MT, Valley County, MT, Wibaux County, MT, Yellowstone County, MT

The radar

The Glasgow radar (KGGW), 122 km from the middle of the area, began a volume at 22:43 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, 10.7 hours before the alert went out and 230 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, 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

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; radar from the NEXRAD Level II archive.