Alert archive / Colorado / Mesoscale Discussions in 2021

Mesoscale Discussion 1749

September 14, 2021Bent County, Colorado

The Storm Prediction Center issued this mesoscale discussion at Sep 14, 2021, 5:30 PM MDT for Bent County, Colorado. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Sep 14, 2021, 5:30 PM MDT (23:30 UTC)
Expired
Sep 14, 2021, 7:00 PM MDT
In force
90 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 499

County Bent County, CO

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.5 hours before the alert went out and 208 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 2021-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 square meters per square second.1939587897Sfc1 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
17 J/kg
Mixed-layer CIN
-309 J/kg
Mixed-layer LCL
1437 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
265 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

204 
ACUS11 KWNS 142331
SWOMCD
SPC MCD 142330 
COZ000-150100-

Mesoscale Discussion 1749
NWS Storm Prediction Center Norman OK
0630 PM CDT Tue Sep 14 2021

Areas affected...Parts of southeastern Colorado

Concerning...Severe Thunderstorm Watch 499...

Valid 142330Z - 150100Z

The severe weather threat for Severe Thunderstorm Watch 499
continues.

SUMMARY...The primary potential severe hazard may transition to
strong surface gusts with a developing cluster of storms as it
spreads across and south-southeast of the La Junta vicinity through
7-8 PM MDT.

DISCUSSION...Earlier isolated supercell development initiating near
and southeast of Colorado Springs has been followed by additional
convective development and upscale growth, aided by moist upslope
flow across the sloping terrain north of the Arkansas River into the
vicinity of the Palmer Divide.  Although mixed-layer CAPE appears
generally modest to weak, shear beneath moderate west-northwesterly
mid-level flow, coupled with steep low-level lapse rates, appears
sufficient to contribute to further convective organization.  This
may be accompanied by increasing potential to produce strong surface
gusts as the convective system propagates across and south-southeast
of the La Junta vicinity through 7-8 PM MDT.

..Kerr.. 09/14/2021

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

ATTN...WFO...PUB...

LAT...LON   38370306 37880259 37400303 37650361 38170380 38170344
            38370306

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 14, 1:08 PM MDTMesoscale DiscussionSPCBent, Cheyenne, Crowley, Elbert, El Paso, Kiowa and 5 more2 hr
Sep 14, 1:55 PM MDTSevere Thunderstorm WatchSPCBaca, Bent, Cheyenne, Crowley, Elbert, El Paso and 10 more7 hr

Nearby

Mesoscale Discussions in Colorado, 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.