Alert archive / Wyoming / Snow Squall Warnings in 2021

Snow Squall Warning 4, NWS Riverton, WY

December 26, 2021Sweetwater County, Wyoming

NWS Riverton, WY issued this snow squall warning at Dec 26, 2021, 11:00 AM MST for Sweetwater County, Wyoming. It was in force for 45 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Dec 26, 2021, 11:00 AM MST (18:00 UTC)
Expired: Dec 26, 2021, 11:45 AM MST
In force: 45 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon

County Sweetwater County, WY

The radar

The Riverton/Lander radar (KRIW), 153 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.

What was reported inside it

Time	Report	Where	Remark
Dec 26, 11:16 AM MST	NON-TSTM WND GST 70	9 W Red Desert, WY	MESONET STATION WY13 RED DESERT 9 W (WYDOT).

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 6.0 hours before the alert went out and 155 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: 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

Open this sounding in Storm Lab

The text

As transmitted.

106 
WWUS55 KRIW 261800
SQWRIW

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Riverton WY
1100 AM MST Sun Dec 26 2021

WYC037-261845-
/O.NEW.KRIW.SQ.W.0004.211226T1800Z-211226T1845Z/
Sweetwater-
1100 AM MST Sun Dec 26 2021

The National Weather Service in Riverton has issued a

* Snow Squall Warning for...
  Central Sweetwater County in south central Wyoming...

* Until 1145 AM MST.

* At 1058 AM MST, a dangerous snow squall was located along a line 
  extending from 10 miles south of Oregon Buttes to Superior to 5 
  miles east of Flaming Gorge, moving east at 35 mph.

  HAZARD...Heavy snow and blowing snow. Wind gusts greater than 40 
           mph. Frequent gusts of 40 to 50 mph have been observed 
           along I-80 during the past hour.

  SOURCE...Radar and webcams.

  IMPACT...Dangerous life-threatening travel.

* This includes Interstate 80 between mile markers 95 and 167.
 
Locations impacted include...
Rock Springs, Superior, Bitter Creek Rest Area, Killpecker Dune 
Field, Reliance, Red Desert, Point Of Rocks, Tipton, Bitter Creek, 
and Flaming Gorge National Recreation Area.

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.

&&

LAT...LON 4215 10919 4226 10783 4100 10836 4100 10957
TIME...MOT...LOC 1758Z 267DEG 30KT 4211 10888 4105 10929 

$$

Straub

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 26, 7:43 AM MST	Special Weather Statement	RIW	Teton	62 min
Dec 26, 8:35 AM MST	Special Weather Statement	RIW	Lincoln, Park, Sublette	55 min
Dec 26, 9:31 AM MST	Snow Squall Warning	RIW	Sweetwater	44 min
Dec 26, 9:37 AM MST	Special Weather Statement	RIW	Fremont, Hot Springs	53 min
Dec 26, 10:12 AM MST	Snow Squall Warning	RIW	Sweetwater	48 min
Dec 26, 10:28 AM MST	Special Weather Statement	RIW	Big Horn, Fremont, Hot Springs	62 min
Dec 26, 11:26 AM MST	Special Weather Statement	RIW	Fremont, Natrona	64 min
Dec 26, 11:38 AM MST	Snow Squall Warning	RIW	Sweetwater	52 min
Dec 26, 1:51 PM MST	Special Weather Statement	RIW	Lincoln	54 min
Dec 26, 2:45 PM MST	Special Weather Statement	RIW	Lincoln, Sublette, Teton	60 min
Dec 26, 3:44 PM MST	Special Weather Statement	RIW	Sublette	46 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.