Alert archive / Montana / Mesoscale Discussions in 2016

Mesoscale Discussion 1496

August 7, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2016, 5:26 PM MDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 7, 2016, 5:26 PM MDT (23:26 UTC)
Expired
Aug 7, 2016, 7:30 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Carter County, MT, Custer County, MT, Fallon County, MT, Powder River County, MT, Wibaux County, MT, Bowman County, ND, Golden Valley County, ND, Butte County, SD, Harding County, SD, Lawrence County, SD, Campbell County, WY, Crook County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 224 km from the middle of the area, began a volume at 23:28 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

Riverton, WY (KRIW), launched 12:00Z, 11.4 hours before the alert went out and 337 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, Riverton, WY at 12:00Z on 2016-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2016-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2103 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
78 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
Aug 7, 11:39 AM MDTMesoscale DiscussionSPCCarbon, Stillwater3 hr
Aug 7, 1:52 PM MDTMesoscale DiscussionSPCBeaverhead, Broadwater, Cascade, Chouteau, Deer Lodge, Fergus and 23 more2 hr
Aug 7, 2:07 PM MDTMesoscale DiscussionSPCBig Horn, Campbell, Carbon, Fremont, Hot Springs, Johnson and 9 more2 hr

Nearby

Mesoscale Discussions in Montana, 2016Mesoscale Discussions in South Dakota, 2016Mesoscale Discussions in Wyoming, 2016Every mesoscale discussion in 2016

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.