Alert archive / Wyoming / Snow Squall Warnings in 2021

Snow Squall Warning 2, NWS Riverton, WY

December 26, 2021Sweetwater County, Wyoming

NWS Riverton, WY issued this snow squall warning at Dec 26, 2021, 9:31 AM MST for Sweetwater County, Wyoming. It was in force for 44 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
Dec 26, 2021, 9:31 AM MST (16:31 UTC)
Expired
Dec 26, 2021, 10:15 AM MST
In force
44 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon

County Sweetwater County, WY

The radar

The Riverton/Lander radar (KRIW), 201 km from the middle of the area, began a volume at 16:32 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 4.5 hours before the alert went out and 202 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, Salt Lake City I, UT at 12:00Z on 2021-12-26Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Salt Lake City I, UT at 12:00Z on 2021-12-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 356 square meters per square second.1939587897117136Sfc1 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
1198 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
356 m²/s²
0-3 km storm-relative helicity
385 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

974 
WWUS55 KRIW 261631
SQWRIW

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

WYC037-261715-
/O.NEW.KRIW.SQ.W.0002.211226T1631Z-211226T1715Z/
Sweetwater-
931 AM MST Sun Dec 26 2021

The National Weather Service in Riverton has issued a

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

* Until 1015 AM MST.

* At 930 AM MST, a dangerous snow squall was located 13 miles east of
  Lyman, or 14 miles south of Granger, moving east at 45 mph.

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

  SOURCE...Radar and webcams.

  IMPACT...Dangerous life-threatening travel.

* This includes Interstate 80 between mile markers 58 and 108.
 
Locations impacted include...
Rock Springs, Green River, Granger, Little America, 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 4168 11004 4180 10924 4121 10905 4109 11005
TIME...MOT...LOC 1630Z 262DEG 41KT 4139 11006 

$$

Straub
1 follow-up statement
869 
WWUS55 KRIW 261654
SQWRIW

Snow Squall Warning
National Weather Service Riverton WY
954 AM MST Sun Dec 26 2021

WYC037-261715-
/O.CON.KRIW.SQ.W.0002.000000T0000Z-211226T1715Z/
Sweetwater-
954 AM MST Sun Dec 26 2021

...A SNOW SQUALL WARNING REMAINS IN EFFECT UNTIL 1015 AM MST FOR
SOUTHWESTERN SWEETWATER COUNTY...

At 953 AM MST, a dangerous snow squall was located along a line
extending from 13 miles northwest of Rock Springs to 9 miles
northeast of Lonetree, moving east at 45 mph.

HAZARD...Heavy snow and blowing snow. Wind gusts greater than 40 mph.

SOURCE...Radar and webcams.

IMPACT...Dangerous life-threatening travel.

This includes Interstate 80 between mile markers 58 and 108.
 
Locations impacted include...
Rock Springs, Green River, Granger, Little America, 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 4168 11004 4180 10924 4121 10905 4109 11005
TIME...MOT...LOC 1653Z 260DEG 46KT 4178 10935 4112 11000 

$$

Straub

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 26, 7:43 AM MSTSpecial Weather StatementRIWTeton62 min
Dec 26, 8:35 AM MSTSpecial Weather StatementRIWLincoln, Park, Sublette55 min
Dec 26, 9:37 AM MSTSpecial Weather StatementRIWFremont, Hot Springs53 min
Dec 26, 10:12 AM MSTSnow Squall WarningRIWSweetwater48 min
Dec 26, 10:28 AM MSTSpecial Weather StatementRIWBig Horn, Fremont, Hot Springs62 min
Dec 26, 11:00 AM MSTSnow Squall WarningRIWSweetwater45 min
Dec 26, 11:26 AM MSTSpecial Weather StatementRIWFremont, Natrona64 min
Dec 26, 11:38 AM MSTSnow Squall WarningRIWSweetwater52 min
Dec 26, 1:51 PM MSTSpecial Weather StatementRIWLincoln54 min
Dec 26, 2:45 PM MSTSpecial Weather StatementRIWLincoln, Sublette, Teton60 min
Dec 26, 3:44 PM MSTSpecial Weather StatementRIWSublette46 min

Nearby

Snow Squall Warnings in Wyoming, 2021Every 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.