Alert archive / Montana / Mesoscale Discussions in 2020

Mesoscale Discussion 992

June 24, 20205 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 24, 2020, 4:28 PM MDT for 5 counties in Montana. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Jun 24, 2020, 4:28 PM MDT (22:28 UTC)
Expired: Jun 24, 2020, 5:30 PM MDT
In force: 62 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

Counties Flathead County, MT, Glacier County, MT, Lake County, MT, Pondera County, MT, Teton County, MT

The radar

The Missoula radar (KMSX), 130 km from the middle of the area, began a volume at 22:30 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 302Jun 24, 5:05 PM MDT

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 10.5 hours before the alert went out and 242 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: 25 J/kg
Mixed-layer CIN: -241 J/kg
Mixed-layer LCL: 2149 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 140 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jun 24, 2:07 PM MDT	Mesoscale Discussion	SPC	Flathead, Lincoln, Sanders	2 hr
Jun 24, 2:29 PM MDT	Mesoscale Discussion	SPC	Beaverhead, Broadwater, Carbon, Deer Lodge, Gallatin, Jefferson and 6 more	2 hr
Jun 24, 5:11 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Chouteau, Glacier, Hill, Liberty, Pondera and 2 more	5 hr

Nearby

Mesoscale Discussions in Montana, 2020 Every mesoscale discussion in 2020

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.