Alert archive / Colorado / Mesoscale Discussions in 2021
Mesoscale Discussion 2059
The Storm Prediction Center issued this mesoscale discussion at Dec 26, 2021, 11:00 AM MST for 5 counties in Colorado; Grand County, Uintah County, Utah; Carbon County, Fremont County, Sweetwater County, Wyoming. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 26, 2021, 11:00 AM MST (18:00 UTC)
- Expired
- Dec 26, 2021, 2:00 PM MST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Snow squall
Counties Garfield County, CO, Mesa County, CO, Moffat County, CO, Rio Blanco County, CO, Routt County, CO, Grand County, UT, Uintah County, UT, Carbon County, WY, Fremont County, WY, Sweetwater County, WY
The radar
The Riverton/Lander radar (KRIW), 213 km from the middle of the area, began a volume at 18:02 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
Riverton, WY (KRIW), launched 12:00Z, 6.0 hours before the alert went out and 213 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
- 1333 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 126 m²/s²
- 0-3 km storm-relative helicity
- 188 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
005
ACUS11 KWNS 261800
SWOMCD
SPC MCD 261800
COZ000-WYZ000-UTZ000-262100-
Mesoscale Discussion 2059
NWS Storm Prediction Center Norman OK
1200 PM CST Sun Dec 26 2021
Areas affected...central WY into northwest CO and far northeast UT
Concerning...Snow Squall
Valid 261800Z - 262100Z
SUMMARY...Heavy snow bands and snow squalls will continue to impact
portions of the MCD area the next few hours. Brief periods of heavy
snow, reduced visibility and strong wind gusts are expected.
DISCUSSION...Snow squalls and occasional bursts of heavy snow near
an eastward-advancing surface cold front will continue to impact
portions of central WY, southward into northwest CO/far northeast UT
the next few hours. This includes portions of the I-80 and I-70
corridors across the MCD area.
A surface low will continue to track east/northeast across northern
WY today. A strong surface pressure gradient and moderate
southwesterly deep-layer flow will result in continued strong gusts
between 35-50 kt, with the strongest gusts noted near/just behind
the cold front. Weak instability and steep midlevel lapse rates will
continue to support convective snow bands along and behind the cold
front. Regional observations have consistently be reporting heavy
snow and visibility reduced to near 1/2-1/4 mile within snow
squalls. This activity should continue for at least the next few
hours across the MCD area
..Leitman.. 12/26/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BOU...CYS...RIW...GJT...
LAT...LON 40360965 41660902 42350897 43160885 43400868 43530816
43510779 43380729 43130696 42600669 41380653 40540647
39630672 39060736 38750832 38770914 38930958 39160994
39470992 40360965SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 26, 8:06 AM MST | Mesoscale Discussion | SPC | Duchesne, Morgan, Rich, Salt Lake, Sanpete, Summit and 2 more | 2 hr |
Nearby
Mesoscale Discussions in Colorado, 2021Mesoscale Discussions in Wyoming, 2021Mesoscale Discussions in Utah, 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.