Alert archive / Montana / Mesoscale Discussions in 2018

Mesoscale Discussion 644

June 4, 201814 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 4, 2018, 6:14 PM MDT for 14 counties in Montana. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 4, 2018, 6:14 PM MDT (00:14 UTC)
Expired
Jun 4, 2018, 8:45 PM MDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
5%

Counties Daniels County, MT, Dawson County, MT, Garfield County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Treasure County, MT, Valley County, MT, Wibaux County, MT

The radar

The Glasgow radar (KGGW), 106 km from the middle of the area, began a volume at 00:16 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 00:00Z, 0.2 hours before the alert went out and 314 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 00:00Z on 2018-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 22 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 00:00Z on 2018-06-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 square meters per square second.1939587897Sfc1 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
22 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
2437 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
236 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

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 5, 5:54 PM MDTMesoscale DiscussionSPCCarter, Fallon2 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.