Alert archive / Colorado / Mesoscale Discussions in 2021

Mesoscale Discussion 1016

June 19, 20216 counties in Colorado; Cheyenne County, Deuel County, Morrill County, Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jun 19, 2021, 3:24 PM MDT for 6 counties in Colorado; Cheyenne County, Deuel County, Morrill County, Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 19, 2021, 3:24 PM MDT (21:24 UTC)
Expired: Jun 19, 2021, 5:30 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 286

Counties Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Cheyenne County, NE, Deuel County, NE, Morrill County, NE

The radar

The Cheyenne radar (KCYS), 167 km from the middle of the area, began a volume at 21:26 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 (KDNR), launched 12:00Z, 9.4 hours before the alert went out and 98 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2627 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -23 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

981 
ACUS11 KWNS 192124
SWOMCD
SPC MCD 192124 
NEZ000-COZ000-192330-

Mesoscale Discussion 1016
NWS Storm Prediction Center Norman OK
0424 PM CDT Sat Jun 19 2021

Areas affected...Nebraska Panhandle and Northeastern Colorado

Concerning...Severe Thunderstorm Watch 286...

Valid 192124Z - 192330Z

The severe weather threat for Severe Thunderstorm Watch 286
continues.

SUMMARY...Numerous strong-to-severe thunderstorms have developed
from the Nebraska Panhandle southward to south-central Colorado. 
These storms will initially pose a threat for large hail and
damaging winds.  As they grow upscale, especially across the eastern
Nebraska Panhandle and northeastern Colorado, the threat for a more
organized wind threat is expected to develop.

DISCUSSION...With numerous thunderstorms across the area in close
proximity to one another, cold pool mergers are already taking place
in the Nebraska Panhandle.  As a result, storms are already
beginning to surge southeastward.  Over the next couple of hours,
these storms and the storms in northeastern Colorado are expected to
grow upscale. Given the steep lapse-rate environment, sufficient
moisture/instability, and increasing midlevel flow/forcing, an
organized severe wind threat is expected to develop.

..Jirak/Guyer.. 06/19/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LBF...GLD...BOU...CYS...

LAT...LON   42010276 42030244 41300219 40620220 39920226 39390244
            39310282 39360363 40310401 41050395 41330338 42010276

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 19, 12:46 PM MDT	Mesoscale Discussion	SPC	Adams, Arapahoe, Cheyenne, Elbert, Kiowa, Kit Carson and 8 more	89 min
Jun 19, 1:44 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Arapahoe, Baca, Bent, Cheyenne, Crowley and 17 more	7 hr
Jun 19, 4:00 PM MDT	Mesoscale Discussion	SPC	Kit Carson, Logan, Phillips, Sedgwick, Washington, Yuma	90 min
Jun 18, 8:27 PM MDT	Mesoscale Discussion	SPC	Cass, Gage, Johnson, Lancaster, Nemaha, Otoe and 2 more	2 hr
Jun 18, 9:08 PM MDT	Severe Thunderstorm Watch	SPC	Johnson, Nemaha, Pawnee, Richardson	8 hr
Jun 19, 3:58 PM MDT	Mesoscale Discussion	SPC	Dawes	92 min
Jun 19, 4:48 PM MDT	Severe Thunderstorm Watch	SPC	Chase, Dawson, Dundy, Frontier, Furnas, Gosper and 8 more	6 hr

Nearby

Mesoscale Discussions in Colorado, 2021 Mesoscale Discussions in Nebraska, 2021 Every mesoscale discussion in 2021

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.