Alert archive / Colorado / Mesoscale Discussions in 2018

Mesoscale Discussion 484

May 21, 20189 counties in Colorado; 4 counties in Nebraska; 4 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at May 21, 2018, 3:00 PM MDT for 9 counties in Colorado; 4 counties in Nebraska; 4 counties in Wyoming. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 21, 2018, 3:00 PM MDT (21:00 UTC)
Expired
May 21, 2018, 5:00 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Adams County, CO, Arapahoe County, CO, Denver County, CO, Kit Carson County, CO, Logan County, CO, Morgan County, CO, Washington County, CO, Weld County, CO, Yuma County, CO, Banner County, NE, Cheyenne County, NE, Kimball County, NE, Scotts Bluff County, NE, Goshen County, WY, Laramie County, WY, Niobrara County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 53 km from the middle of the area, began a volume at 21:00 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

Denver, CO (KDEN), launched 12:00Z, 9.0 hours before the alert went out and 168 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, Denver, CO at 12:00Z on 2018-05-21Temperature 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, Denver, CO at 12:00Z on 2018-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1541 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
122 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
May 21, 11:41 AM MDTMesoscale DiscussionSPCArchuleta, Conejos, Mineral, Rio Grande2 hr

Nearby

Mesoscale Discussions in Colorado, 2018Mesoscale Discussions in Nebraska, 2018Mesoscale Discussions in Wyoming, 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.