Mesoscale Discussion 609

Issued

May 14, 2021, 1:56 PM MDT (19:56 UTC)

Expired

May 14, 2021, 4:00 PM MDT

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

Counties Adams County, CO, Arapahoe County, CO, Cheyenne County, CO, Denver County, CO, Elbert County, CO, Kit Carson County, CO, Lincoln County, CO, Morgan County, CO, Washington County, CO, Weld County, CO, Yuma County, CO, Laramie County, WY

The Denver radar (KFTG), 76 km from the middle of the area, began a volume at 19:55 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.

• Severe Thunderstorm Watch 170May 14, 3:45 PM MDT

332 
ACUS11 KWNS 141957
SWOMCD
SPC MCD 141956 
COZ000-NEZ000-WYZ000-142200-

Mesoscale Discussion 0609
NWS Storm Prediction Center Norman OK
0256 PM CDT Fri May 14 2021

Areas affected...Eastern Colorado...southeast Wyoming...and far
western Nebraska

Concerning...Severe potential...Watch unlikely 

Valid 141956Z - 142200Z

Probability of Watch Issuance...20 percent

SUMMARY...Scattered thunderstorm development along the Front Range
may pose a risk for isolated damaging wind gusts over the next
several hours. A greater severe threat may evolve later this
afternoon/early this evening as storms move toward eastern Colorado.
A weather watch is unlikely in the next couple of hours.

DISCUSSION...As of 1930 UTC, visible satellite showed several areas
of high-based convection and weak thunderstorms from the southern
Laramie Range across eastern Wyoming into north-central Colorado.
Additional convective development appears likely ahead of a weak
shortwave trough within northwest flow across the central Rockies.
Surface observations showed weak upslope flow was occurring across
much of the central High Plains with 40s and 50s F dewpoints slowly
advancing westward. SPC Mesoanalysis and hi-res model sounding
trends suggest that convection will continue to strengthen as
afternoon heating erodes remaining MLCINH and the atmosphere
gradually destabilizes. 25-35 kts of effective shear should support
only modest storm organization in the form of multi-cell clusters
through this afternoon. Large temperature/dew point spreads of 20-30
degrees F suggest the primary threat with any stronger thunderstorms
will be damaging wind gusts, though small hail will also be possible
given steep mid-level lapse rates around 9 C/km.

As storm development continues later this afternoon and early this
evening, consolidating outflow/deeper cold pools may support a
gradual increase in convective coverage/organization as storms
approach far eastern Colorado and western Kansas. Hi-res guidance
hints at the development of an MCS or storm cluster capable of
producing a greater damaging wind threat as storms begin to
encounter greater buoyancy from increasing boundary-layer moisture
(dewpoints 50-60 F). Details on convective evolution remain scant,
but a more focused corridor for damaging wind potential, requiring a
weather watch, may evolve out of the ongoing storms.

..Lyons/Kerr.. 05/14/2021

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

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

LAT...LON   40870352 40440313 40200260 40050230 39680226 39240221
            38930234 38770271 38660325 38660383 38840445 39430493
            40150496 40680503 41080531 41350562 41750547 41890510
            41760457 41360399 40870352

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

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.