Alert archive / Colorado / Mesoscale Discussions in 2021

Mesoscale Discussion 971

June 14, 202122 counties in Colorado; Banner County, Kimball County, Scotts Bluff County, Nebraska; Laramie County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jun 14, 2021, 2:51 PM MDT for 22 counties in Colorado; Banner County, Kimball County, Scotts Bluff County, Nebraska; Laramie County, Wyoming. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Jun 14, 2021, 2:51 PM MDT (20:51 UTC)
Expired
Jun 14, 2021, 4:45 PM MDT
In force
114 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 26 counties

Adams County, CO, Arapahoe County, CO, Bent County, CO, Boulder County, CO, Broomfield County, CO, Crowley County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Huerfano County, CO, Jefferson County, CO, Kiowa County, CO, Las Animas County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Otero County, CO, Pueblo County, CO, Teller County, CO, Washington County, CO, Weld County, CO, Banner County, NE, Kimball County, NE, Scotts Bluff County, NE, Laramie County, WY

The radar

The Denver radar (KFTG), 35 km from the middle of the area, began a volume at 20:52 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, 8.9 hours before the alert went out and 78 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 2021-06-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 677 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-06-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 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
677 J/kg
Mixed-layer CIN
-353 J/kg
Mixed-layer LCL
2390 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

994 
ACUS11 KWNS 142051
SWOMCD
SPC MCD 142051 
COZ000-NEZ000-NMZ000-WYZ000-142245-

Mesoscale Discussion 0971
NWS Storm Prediction Center Norman OK
0351 PM CDT Mon Jun 14 2021

Areas affected...Portions of central and eastern Colorado...far
southeast Wyoming...southwestern Nebraska Panhandle

Concerning...Severe potential...Watch unlikely 

Valid 142051Z - 142245Z

Probability of Watch Issuance...20 percent

SUMMARY...Gradual development of isolated thunderstorms is expected
through the remainder of the afternoon/evening. A WW issuance is not
expected given the sparse nature of the severe threat.

DISCUSSION...Mesoanalysis trends continue to indicate eroding MLCINH
to the immediate lee of the Rockies, where visible satellite and
MRMS mosaic radar show convective initiation underway. Surface
temperatures have warmed to over 90F, with south-southeasterly
surface flow advecting 60F dewpoints to the Colorado Front Range.
Still, given the very warm low-levels, a dry boundary/sub-cloud
layer has developed, with 9+ C/km surface-500 mb lapse rates
present. Any storm that manages to develop in the weakly forced
environment will be high based, with damaging gusts the primary
threat given the dry, warm sub-cloud layer, though some small hail
may still accompany the more persistent updrafts. Damaging gusts
will be most likely with any cellular/cold pool mergers that can
occur. However, the severe wind/hail coverage is expected to remain
isolated, and a WW issuance is not anticipated.

..Squitieri/Grams.. 06/14/2021

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

ATTN...WFO...GLD...PUB...BOU...CYS...ABQ...

LAT...LON   37110460 38030525 39120546 39710549 40720544 41450540
            41690533 41940505 42050464 42060425 41960376 41820350
            41520331 40850306 39900280 39320273 38410269 37700286
            37260320 36950368 37110460

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 13, 6:15 PM MDTMesoscale DiscussionSPCLogan, Phillips, Sedgwick2 hr
Jun 13, 8:39 PM MDTMesoscale DiscussionSPCArthur, Cherry, Garden, Grant, Hooker, McPherson and 1 more2 hr
Jun 14, 1:24 PM MDTMesoscale DiscussionSPCSioux3 hr

Nearby

Mesoscale Discussions in Colorado, 2021Mesoscale Discussions in Nebraska, 2021Mesoscale Discussions in Wyoming, 2021Every 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.