Alert archive / Colorado / Mesoscale Discussions in 2014

Mesoscale Discussion 636

May 21, 20147 counties in Colorado; 4 counties in Nebraska; 5 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at May 21, 2014, 12:09 PM MDT for 7 counties in Colorado; 4 counties in Nebraska; 5 counties in Wyoming. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: May 21, 2014, 12:09 PM MDT (18:09 UTC)
Expired: May 21, 2014, 1:45 PM MDT
In force: 96 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

Counties Adams County, CO, Arapahoe County, CO, Broomfield County, CO, Denver County, CO, Elbert County, CO, Morgan County, CO, Weld County, CO, Banner County, NE, Kimball County, NE, Scotts Bluff County, NE, Sioux County, NE, Converse County, WY, Goshen County, WY, Laramie County, WY, Niobrara County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 55 km from the middle of the area, began a volume at 18:09 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.

Tornado Watch 165May 21, 12:35 PM MDT

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 6.2 hours before the alert went out and 234 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: 268 J/kg
Mixed-layer CIN: -75 J/kg
Mixed-layer LCL: 786 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 158 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 6:02 PM MDT	Mesoscale Discussion	SPC	Cheyenne, Kit Carson, Phillips, Sedgwick, Yuma	88 min
May 20, 6:27 PM MDT	Severe Thunderstorm Watch	SPC	Cheyenne, Kit Carson, Phillips, Sedgwick, Yuma	4 hr
May 20, 8:06 PM MDT	Mesoscale Discussion	SPC	Cheyenne, Kit Carson, Lincoln, Logan, Phillips, Sedgwick and 2 more	84 min
May 21, 12:34 PM MDT	Tornado Watch	SPC	Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas and 5 more	8 hr
May 21, 1:42 PM MDT	Mesoscale Discussion	SPC	Baca, Bent, Crowley, El Paso, Kiowa, Las Animas and 4 more	63 min
May 21, 1:58 PM MDT	Mesoscale Discussion	SPC	Broomfield, Denver, Jefferson	62 min
May 21, 2:18 PM MDT	Severe Thunderstorm Watch	SPC	Baca, Bent, Crowley, El Paso, Huerfano, Kiowa and 4 more	4 hr
May 21, 4:17 PM MDT	Mesoscale Discussion	SPC	Cheyenne, Elbert, Kit Carson, Lincoln, Washington, Yuma	58 min
May 21, 4:48 PM MDT	Severe Thunderstorm Watch	SPC	Cheyenne, Kit Carson, Lincoln, Washington, Yuma	6 hr

Nearby

Mesoscale Discussions in Colorado, 2014 Mesoscale Discussions in Wyoming, 2014 Mesoscale Discussions in Nebraska, 2014 Every mesoscale discussion in 2014

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.