Alert archive / Colorado / Mesoscale Discussions in 2021

Mesoscale Discussion 1295

July 15, 20218 counties in Colorado; Banner County, Kimball County, Nebraska; Goshen County, Laramie County, Platte County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jul 15, 2021, 2:09 PM MDT for 8 counties in Colorado; Banner County, Kimball County, Nebraska; Goshen County, Laramie County, Platte County, Wyoming. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jul 15, 2021, 2:09 PM MDT (20:09 UTC)
Expired
Jul 15, 2021, 4:45 PM MDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Adams County, CO, Arapahoe County, CO, Crowley County, CO, Elbert County, CO, Lincoln County, CO, Morgan County, CO, Washington County, CO, Weld County, CO, Banner County, NE, Kimball County, NE, Goshen County, WY, Laramie County, WY, Platte County, WY

The radar

The Denver radar (KFTG), 73 km from the middle of the area, began a volume at 20:11 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, 8.2 hours before the alert went out and 88 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 2021-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 2021-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.19395878Sfc1 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
6 J/kg
Mixed-layer CIN
-427 J/kg
Mixed-layer LCL
1726 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

775 
ACUS11 KWNS 152009
SWOMCD
SPC MCD 152009 
COZ000-NEZ000-WYZ000-152245-

Mesoscale Discussion 1295
NWS Storm Prediction Center Norman OK
0309 PM CDT Thu Jul 15 2021

Areas affected...Southeast WY...Southwest NE Panhandle...Eastern CO

Concerning...Severe potential...Watch unlikely 

Valid 152009Z - 152245Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong storms are possible this afternoon and
evening, with a threat of isolated severe hail and wind.

DISCUSSION...A thunderstorm has recently developed near Limon,
Colorado, with other convection increasing to the northwest across
the higher terrain of southeast WY. While storm coverage will likely
remain isolated due to weak large-scale ascent, weak-to-moderate
instability and low-level southeasterly flow veering to modest
northwesterly flow aloft will support the potential for organized
storms. A supercell or two may eventually develop and track
southeastward, posing a localized risk of hail and severe gusts. The
severe risk is expected to be diurnally driven and peak during the
late afternoon/early evening before nocturnal stabilization reduces
the threat with time tonight.

..Dean/Bunting.. 07/15/2021

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

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

LAT...LON   38490267 38040395 38790430 39980476 40920520 41310548
            42150579 42420514 42110412 41910396 41060325 39990294
            38980271 38490267

Nearby

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