Alert archive / Wyoming / Snow Squall Warnings in 2021

Snow Squall Warning 2, NWS Cheyenne, WY

January 5, 2021Albany County, Laramie County, Wyoming

NWS Cheyenne, WY issued this snow squall warning at Jan 5, 2021, 4:55 PM MST for Albany County, Laramie County, Wyoming. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jan 5, 2021, 4:55 PM MST (23:55 UTC)
Expired: Jan 5, 2021, 5:45 PM MST
In force: 50 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon

Counties Albany County, WY, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 49 km from the middle of the area, began a volume at 23:53 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, 11.9 hours before the alert went out and 234 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2560 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 148 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

701 
WWUS55 KCYS 052356
SQWCYS

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Cheyenne WY
455 PM MST Tue Jan 5 2021

WYC001-021-060045-
/O.NEW.KCYS.SQ.W.0002.210105T2355Z-210106T0045Z/
Albany WY-Laramie WY-
455 PM MST Tue Jan 5 2021

The National Weather Service in Cheyenne has issued a

* Snow Squall Warning for...
  Southeastern Albany County in southeastern Wyoming...
  Southwestern Laramie County in southeastern Wyoming...

* Until 545 PM MST.

* At 455 PM MST, a dangerous snow squall was located near Pumpkin
  Vine, or 19 miles southeast of Laramie, moving south at 30 mph.

  HAZARD...Whiteout conditions. Zero visibility in heavy snow and 
           blowing snow. Wind gusts greater than 30 mph.

  SOURCE...Radar indicated.

  IMPACT...Dangerous life-threatening travel.

* 

This includes Interstate 80 in Wyoming between mile markers 319 and
340.
 
Locations impacted include...
Tie City Campground, Granite Springs Reservoir, North Crow
Campground, Vedauwoo, Tie Siding, Granite Springs Campground, Pumpkin
Vine, Vedauwoo Campground, Buford and Yellow Pine Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Consider avoiding or delaying travel until the snow squall passes
your location. If you must travel, use extra caution and allow extra
time. Rapid changes in visibility and slick road conditions may lead
to accidents.

Slow Down! Rapid changes in visibility and road conditions are
expected with this dangerous snow squall. Be alert for sudden
whiteout conditions.

&&

LAT...LON 4134 10548 4123 10522 4100 10521 4100 10558
TIME...MOT...LOC 2355Z 357DEG 28KT 4108 10538 

$$

Wilkinson/Braun

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 4, 7:54 PM MST	Winter Weather Advisory	CYS	Albany, Carbon	21 hr
Jan 5, 4:13 PM MST	Special Weather Statement	CYS	Laramie	32 min
Jan 5, 4:31 PM MST	Snow Squall Warning	CYS	Laramie	44 min

Nearby

Snow Squall Warnings in Wyoming, 2021 Every snow squall warning 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.