Alert archive / Montana / Mesoscale Discussions in 2018

Mesoscale Discussion 686

June 9, 201821 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 9, 2018, 4:53 PM MDT for 21 counties in Montana. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Jun 9, 2018, 4:53 PM MDT (22:53 UTC)
Expired
Jun 9, 2018, 6:30 PM MDT
In force
97 min
Issued by
the Storm Prediction Center
All 21 counties

Broadwater County, MT, Cascade County, MT, Chouteau County, MT, Deer Lodge County, MT, Flathead County, MT, Glacier County, MT, Granite County, MT, Hill County, MT, Jefferson County, MT, Judith Basin County, MT, Lake County, MT, Lewis and Clark County, MT, Liberty County, MT, Meagher County, MT, Missoula County, MT, Pondera County, MT, Powell County, MT, Ravalli County, MT, Silver Bow County, MT, Teton County, MT, Toole County, MT

The radar

The Great Falls radar (KTFX), 26 km from the middle of the area, began a volume at 22:54 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, 10.9 hours before the alert went out and 85 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-pSkew-T log-p diagram, Great_falls, MT at 12:00Z on 2018-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 2018-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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.

IssuedProductOfficeCountiesLasted
Jun 9, 1:06 PM MDTMesoscale DiscussionSPCCascade, Deer Lodge, Flathead, Glacier, Granite, Lake and 8 more114 min
Jun 9, 1:46 PM MDTSevere Thunderstorm WatchSPCBlaine, Broadwater, Cascade, Chouteau, Deer Lodge, Fergus and 14 more7 hr
Jun 9, 2:50 PM MDTMesoscale DiscussionSPCCarter, Powder River2 hr

Nearby

Mesoscale Discussions in Montana, 2018Every 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.