Alert archive / Wyoming / Mesoscale Discussions in 2016

Mesoscale Discussion 1732

September 23, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Sep 23, 2016, 1:23 PM MDT for 4 states. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Sep 23, 2016, 1:23 PM MDT (19:23 UTC)
Expired: Sep 23, 2016, 2:30 PM MDT
In force: 67 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Weld County, CO, Banner County, NE, Box Butte County, NE, Dawes County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sioux County, NE, Custer County, SD, Fall River County, SD, Lawrence County, SD, Campbell County, WY, Converse County, WY, Crook County, WY, Goshen County, WY, Laramie County, WY, Niobrara County, WY, Platte County, WY, Weston County, WY

The radar

The Cheyenne radar (KCYS), 153 km from the middle of the area, began a volume at 19:23 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 487Sep 23, 2:20 PM MDT

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 7.4 hours before the alert went out and 233 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: 3 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 468 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 149 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

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
Sep 23, 2:21 PM MDT	Severe Thunderstorm Watch	SPC	Banner, Box Butte, Dawes, Scotts Bluff, Sioux	8 hr
Sep 23, 5:35 PM MDT	Mesoscale Discussion	SPC	Banner, Box Butte, Cheyenne, Dawes, Kimball, Morrill and 3 more	85 min

Nearby

Mesoscale Discussions in Wyoming, 2016 Mesoscale Discussions in Nebraska, 2016 Mesoscale Discussions in South Dakota, 2016 Every 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.