Alert archive / Montana / Mesoscale Discussions in 2018

Mesoscale Discussion 683

June 9, 201814 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 9, 2018, 1:06 PM MDT for 14 counties in Montana. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: Jun 9, 2018, 1:06 PM MDT (19:06 UTC)
Expired: Jun 9, 2018, 3:00 PM MDT
In force: 114 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

Counties Cascade County, MT, Deer Lodge County, MT, Flathead County, MT, Glacier County, MT, Granite County, MT, Lake County, MT, Lewis and Clark County, MT, Liberty County, MT, Missoula County, MT, Pondera County, MT, Powell County, MT, Ravalli County, MT, Teton County, MT, Toole County, MT

The radar

The Missoula radar (KMSX), 76 km from the middle of the area, began a volume at 19:07 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 166Jun 9, 1:45 PM MDT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 7.1 hours before the alert went out and 189 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: 12 J/kg
Mixed-layer CIN: -295 J/kg
Mixed-layer LCL: 2250 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 76 m²/s²
0-3 km storm-relative helicity: 77 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 9, 1:46 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Broadwater, Cascade, Chouteau, Deer Lodge, Fergus and 14 more	7 hr
Jun 9, 2:50 PM MDT	Mesoscale Discussion	SPC	Carter, Powder River	2 hr
Jun 9, 4:53 PM MDT	Mesoscale Discussion	SPC	Broadwater, Cascade, Chouteau, Deer Lodge, Flathead, Glacier and 15 more	97 min

Nearby

Mesoscale Discussions in Montana, 2018 Every mesoscale discussion in 2018

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.