Alert archive / Colorado / Mesoscale Discussions in 2021
Mesoscale Discussion 175
The Storm Prediction Center issued this mesoscale discussion at Mar 14, 2021, 9:21 AM MDT for 13 counties in Colorado; 6 counties in Nebraska; Goshen County, Laramie County, Wyoming. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 14, 2021, 9:21 AM MDT (15:21 UTC)
- Expired
- Mar 14, 2021, 1:15 PM MDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Blizzard
All 21 counties
Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Clear Creek County, CO, Denver County, CO, Douglas County, CO, Gilpin County, CO, Jefferson County, CO, Larimer County, CO, Logan County, CO, Morgan County, CO, Weld County, CO, Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Goshen County, WY, Laramie County, WY
The radar
The Cheyenne radar (KCYS), 79 km from the middle of the area, began a volume at 15:23 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, 3.4 hours before the alert went out and 119 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 605 m above ground
- 0-6 km bulk shear
- 86 kt
- 0-1 km storm-relative helicity
- 331 m²/s²
- 0-3 km storm-relative helicity
- 383 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
953
ACUS11 KWNS 141521
SWOMCD
SPC MCD 141521
NEZ000-COZ000-WYZ000-141915-
Mesoscale Discussion 0175
NWS Storm Prediction Center Norman OK
1021 AM CDT Sun Mar 14 2021
Areas affected...Southeast Wyoming and northern Colorado
Concerning...Blizzard
Valid 141521Z - 141915Z
SUMMARY...Heavy snow and blizzard conditions are expected to
continue through early afternoon before conditions start to improve
by mid to late afternoon.
DISCUSSION...Strong upslope flow continues across much of southeast
Wyoming and the northern Colorado Front Range. Snowfall rates of 2
to 3 inches per hour have been observed and will likely continue
through the remainder of the morning. Winds will slowly back through
time and become more northerly as the upper-level trough starts to
shift east over the Plains. This will start to decrease snowfall
rates across much of the region by mid afternoon. However, until
that time, heavy snow is expected to persist with the heaviest
snowfall from areas northwest of Boulder to areas near Cheyenne and
Laramie.
In addition to the heavy snow, winds are very strong in the region
with sustained winds of 25 to 30 knots and gusts 40 to 45 knots
leading to blizzard conditions in some locations. These winds are
also forecast to weaken through the afternoon with blizzard
conditions also likely coming to an end by mid-to-late afternoon.
..Bentley.. 03/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...PUB...BOU...CYS...
LAT...LON 39080525 39520571 39820587 41110621 42040528 42290439
42290333 42150280 41610263 41140273 40750287 40260321
39640390 39080466 39020475 39080525SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 13, 7:15 PM MST | Mesoscale Discussion | SPC | Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver and 11 more | 6 hr |
| Mar 13, 7:39 PM MST | Mesoscale Discussion | SPC | Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver and 11 more | 6 hr |
| Mar 14, 1:55 AM MST | Mesoscale Discussion | SPC | Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas and 5 more | 6 hr |
| Mar 14, 11:40 AM MDT | Mesoscale Discussion | SPC | Box Butte, Brown, Cherry, Dawes, Grant, Keya Paha and 4 more | 4 hr |
| Mar 14, 5:20 PM MDT | Mesoscale Discussion | SPC | Boyd, Burt, Cedar, Dakota, Dixon, Keya Paha and 3 more | 6 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.