Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 228

March 22, 2021Cheyenne County, Kiowa County, Colorado; 6 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at Mar 22, 2021, 12:27 PM MDT for Cheyenne County, Kiowa County, Colorado; 6 counties in Kansas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 22, 2021, 12:27 PM MDT (18:27 UTC)
Expired
Mar 22, 2021, 3:30 PM MDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Heavy snow

Counties Cheyenne County, CO, Kiowa County, CO, Greeley County, KS, Logan County, KS, Rawlins County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS

The radar

The Goodland radar (KGLD), 51 km from the middle of the area, began a volume at 18:29 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, 6.5 hours before the alert went out and 161 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 2021-03-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-03-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
692 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

616 
ACUS11 KWNS 221828
SWOMCD
SPC MCD 221827 
KSZ000-COZ000-222130-

Mesoscale Discussion 0228
NWS Storm Prediction Center Norman OK
0127 PM CDT Mon Mar 22 2021

Areas affected...Eastern Colorado and Northwest Kansas

Concerning...Heavy snow 

Valid 221827Z - 222130Z

SUMMARY...Moderate to heavy snow should persist within a focused
band across southeast Colorado into northwestern Kansas through
around 4 PM CDT. Periodic snowfall rates up to one inch per hour and
reduced visibility are possible.

DISCUSSION...A relatively persistent band of precipitation has been
noted over the past 1-2 hours across southeast CO into northwest KS.
Surface observations under this band reveal temperatures at or just
above freezing with visibility reductions between one half to one
mile due to moderate to heavy snowfall. 

This band is primarily being driven by a combination of broad
mid-level isentropic ascent overlaid with a more focused zone of
frontogenesis between the 850-700 mb layer. Frontogenetical forcing
will likely persist at least for the next 2-3 hours across far
eastern CO/northwest KS before cross-frontal flow weakens with the
eastward progression of the main synoptic low to the south.
Additionally, IR satellite imagery shows subtle convective updrafts
embedded within the band that are likely contributing to localized
areas of higher precipitation. Although thermodynamic profiles will
continue to support snowfall production above the surface, warm
temperatures near the ground will limit the spatial extent of the
moderate/heavy snowfall potential. However, locations that remain
near freezing may see periodic snowfall rates up to one inch per
hour over the coming hours.

..Moore.. 03/22/2021

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

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

LAT...LON   38740129 38440178 38210219 38180248 38380285 38740293
            38950276 39370219 39730158 39830103 39540055 39120067
            38740129

Nearby

Mesoscale Discussions in Kansas, 2021Mesoscale 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; radar from the NEXRAD Level II archive.