Alert archive / Wyoming / Winter Storm Warnings in 2021

Winter Storm Warning 12, NWS Cheyenne, WY

April 18, 2021Albany County, Laramie County, Wyoming

NWS Cheyenne, WY issued this winter storm warning at Apr 18, 2021, 6:34 PM MDT for Albany County, Laramie County, Wyoming. It took effect at Apr 19, 2021, 9:00 AM MDT. It was in force for 17 hr. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Apr 18, 2021, 6:34 PM MDT (00:34 UTC)
In effect from
Apr 19, 2021, 9:00 AM MDT
Expired
Apr 20, 2021, 2:10 AM MDT
In force
17 hr
Issued by
NWS Cheyenne, WY

Counties Albany County, WY, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 50 km from the middle of the area, began a volume at 00:31 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

TimeReportWhereRemark
Apr 19, 9:51 PM MDTSNOW 3Buford, WYREPORT RECEIVED FROM WYDOT TMC.

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

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 0.6 hours before the alert went out and 245 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, Denver, CO at 00:00Z on 2021-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 joules per kilogram.LCLLFCEL10008507005003002001001 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, Denver, CO at 00:00Z on 2021-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.193958Sfc1 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
12 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
2439 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

335 
WWUS45 KCYS 190034
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
634 PM MDT Sun Apr 18 2021

...STRONG COLD FRONT WILL BRING MUCH COLDER TEMPERATURES AND
ACCUMULATING SNOW LATE TONIGHT THROUGH LATE MONDAY...

WYZ116-191200-
/O.UPG.KCYS.WS.A.0006.210419T1500Z-210420T0900Z/
/O.NEW.KCYS.WS.W.0012.210419T1500Z-210420T0900Z/
South Laramie Range-
Including the cities of Buford, Pumpkin Vine, and Vedauwoo
634 PM MDT Sun Apr 18 2021

...WINTER STORM WARNING IN EFFECT FROM 9 AM MONDAY TO 3 AM MDT
TUESDAY...

* WHAT...Heavy snow and blowing snow expected. Total snow 
  accumulations of 5 to 8 inches. Winds gusting as high as 40 mph.

* WHERE...South Laramie Range including the Interstate 80 Summit 
  and Vedauwoo.

* WHEN...From 9 AM Monday to 3 AM MDT Tuesday.

* IMPACTS...Travel could be very difficult with snow covered
  roads. Blowing snow could significantly reduce visibility. The
  hazardous conditions could impact the Monday evening commute
  along Interstate 80 between Cheyenne and Laramie.

* ADDITIONAL DETAILS...Heaviest snowfall expected Monday afternoon 
  and early evening with snowfall rates near 1 inch per hour along
  the higher elevations.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

NEZ002-095-WYZ101-102-191200-
/O.CON.KCYS.WW.Y.0029.210419T0500Z-210420T0000Z/
Dawes County-Northern Sioux County-
Converse County Lower Elevations-Niobrara County-
Including the cities of Chadron, Chadron St Park, Harrison, 
Douglas, Glenrock, Bill, Deer Creek, Lusk, and Redbird
634 PM MDT Sun Apr 18 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 11 PM THIS
EVENING TO 6 PM MDT MONDAY...

* WHAT...Snow expected. Total snow accumulations of 3 to 5 
  inches, with locally higher amounts possible along the Pine 
  Ridge.

* WHERE...East Central Wyoming and the Northern Nebraska 
  Panhandle, including Douglas, Lusk, and Chadron.

* WHEN...From 11 PM this evening to 6 PM MDT Monday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the Monday morning and evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

WYZ103-191200-
/O.CON.KCYS.WW.Y.0029.210419T0900Z-210420T0500Z/
North Laramie Range-
Including the cities of Garrett and Esterbrook
634 PM MDT Sun Apr 18 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 3 AM TO 11 PM
MDT MONDAY...

* WHAT...Snow expected. Total snow accumulations of 5 to 9 
  inches. Winds gusting as high as 35 mph.

* WHERE...North Laramie Range.

* WHEN...From 3 AM to 11 PM MDT Monday.

* IMPACTS...Travel could be very difficult. Blowing snow could 
  significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

NEZ020-054-WYZ105>108-110-114-115-117>119-191200-
/O.CON.KCYS.WW.Y.0029.210419T1500Z-210420T0500Z/
Banner County-Kimball County-Shirley Basin-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-North Snowy Range Foothills-
Snowy Range-Laramie Valley-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
Including the cities of Harrisburg, Kimball, Medicine Bow, 
Shirley Basin, Bordeaux, Wheatland, Guernsey, Torrington, 
Arlington, Elk Mountain, Centennial, Albany, Laramie, Bosler, 
Whitaker, Federal, Horse Creek, Cheyenne, and Pine Bluffs
634 PM MDT Sun Apr 18 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 9 AM TO 11 PM
MDT MONDAY...

* WHAT...Snow expected. Total snow accumulations of 3 to 6 
  inches, with 6 to 8 inches for the Snowy Range. Winds gusting 
  as high as 35 mph.

* WHERE...Southeast Wyoming and portions of South Central 
  Wyoming including Arlington, Cheyenne, Kimball, Laramie, Pine 
  Bluffs, and Torrington.

* WHEN...From 9 AM to 11 PM MDT Monday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing snow
  could significantly reduce visibility. The hazardous conditions
  could impact the Monday evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

Brothers
4 follow-up statements
487 
WWUS45 KCYS 190841
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
241 AM MDT Mon Apr 19 2021

...STRONG COLD FRONT WILL BRING MUCH COLDER TEMPERATURES AND
ACCUMULATING SNOW THROUGH THIS EVENING...

WYZ116-192300-
/O.CON.KCYS.WS.W.0012.210419T1500Z-210420T0900Z/
South Laramie Range-
Including the cities of Buford, Pumpkin Vine, and Vedauwoo
241 AM MDT Mon Apr 19 2021

...WINTER STORM WARNING REMAINS IN EFFECT FROM 9 AM THIS MORNING
TO 3 AM MDT TUESDAY...

* WHAT...Heavy snow and blowing snow expected. Total snow
  accumulations of 5 to 8 inches. Winds gusting as high as 40 mph
  will created areas of drifting snow. 

* WHERE...South Laramie Range including the Interstate 80 Summit 
  and Vedauwoo.

* WHEN...From 9 AM Monday to 3 AM MDT Tuesday.

* IMPACTS...Travel could be very difficult with snow covered 
  roads. Blowing snow could significantly reduce visibility. The 
  hazardous conditions could impact the Monday evening commute 
  along Interstate 80 between Cheyenne and Laramie.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

NEZ002-095-WYZ101-102-192300-
/O.CON.KCYS.WW.Y.0029.000000T0000Z-210420T0000Z/
Dawes County-Northern Sioux County-
Converse County Lower Elevations-Niobrara County-
Including the cities of Chadron, Chadron St Park, Harrison, 
Douglas, Glenrock, Bill, Deer Creek, Lusk, and Redbird
241 AM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 3 to 5 
  inches, with locally higher amounts possible along the Pine 
  Ridge.

* WHERE...East Central Wyoming and the Northern Nebraska 
  Panhandle, including Douglas, Lusk, and Chadron.

* WHEN...From 11 PM this evening to 6 PM MDT Monday.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the Monday morning and evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

WYZ103-192300-
/O.CON.KCYS.WW.Y.0029.210419T0900Z-210420T0500Z/
North Laramie Range-
Including the cities of Garrett and Esterbrook
241 AM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 PM MDT THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 5 to 9 
  inches. Winds gusting as high as 35 mph.

* WHERE...Northern Laramie Range.

* WHEN...Until 11 PM MDT Monday.

* IMPACTS...Travel could be very difficult. Blowing snow could 
  significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

NEZ020-054-WYZ105>108-110-114-115-117>119-192300-
/O.CON.KCYS.WW.Y.0029.210419T1500Z-210420T0500Z/
Banner County-Kimball County-Shirley Basin-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-North Snowy Range Foothills-
Snowy Range-Laramie Valley-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
Including the cities of Harrisburg, Kimball, Medicine Bow, 
Shirley Basin, Bordeaux, Wheatland, Guernsey, Torrington, 
Arlington, Elk Mountain, Centennial, Albany, Laramie, Bosler, 
Whitaker, Federal, Horse Creek, Cheyenne, and Pine Bluffs
241 AM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 9 AM THIS
MORNING TO 11 PM MDT THIS EVENING...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 
  inches, with 6 to 10 inches for the Snowy Range. Winds gusting 
  as high as 35 mph.

* WHERE...Southeast Wyoming and portions of South Central 
  Wyoming including Arlington, Cheyenne, Kimball, Laramie, Pine 
  Bluffs, and Torrington.

* WHEN...From 9 AM to 11 PM MDT Monday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow could significantly reduce visibility. The hazardous 
  conditions could impact the Monday evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$
783 
WWUS45 KCYS 200228
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
828 PM MDT Mon Apr 19 2021

...STRONG COLD FRONT WILL BRING MUCH COLDER TEMPERATURES AND
ACCUMULATING SNOW THROUGH THIS EVENING...

WYZ103-105>108-200330-
/O.CAN.KCYS.WW.Y.0029.000000T0000Z-210420T0500Z/
North Laramie Range-Shirley Basin-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-
Including the cities of Garrett, Esterbrook, Medicine Bow, 
Shirley Basin, Bordeaux, Wheatland, Guernsey, and Torrington
828 PM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY IS CANCELLED...

Snow is beginning to taper off north to south across southeast
Wyoming and W Nebraska.

$$

WYZ116-200900-
/O.CON.KCYS.WS.W.0012.000000T0000Z-210420T0900Z/
South Laramie Range-
Including the cities of Buford, Pumpkin Vine, and Vedauwoo
828 PM MDT Mon Apr 19 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 3 AM MDT
TUESDAY...

* WHAT...Heavy snow and blowing snow expected. Total snow 
  accumulations of 5 to 8 inches. Winds gusting as high as 40 
  mph will created areas of drifting snow.

* WHERE...South Laramie Range including the Interstate 80 Summit 
  and Vedauwoo.

* WHEN...From 9 AM Monday to 3 AM MDT Tuesday.

* IMPACTS...Travel could be very difficult with snow covered 
  roads. Blowing snow could significantly reduce visibility. The 
  hazardous conditions could impact the Monday evening commute 
  along Interstate 80 between Cheyenne and Laramie.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

NEZ020-054-WYZ117>119-200700-
/O.EXT.KCYS.WW.Y.0029.000000T0000Z-210420T0700Z/
Banner County-Kimball County-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
Including the cities of Harrisburg, Kimball, Whitaker, Federal, 
Horse Creek, Cheyenne, and Pine Bluffs
828 PM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 1 AM MDT TUESDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 
  inches, with 6 to 10 inches for the Snowy Range. Winds gusting 
  as high as 35 mph.

* WHERE...Southeast Wyoming and portions of South Central Wyoming
  including Cheyenne, Kimball, Pine Bluffs, Harrisburg, Whitaker,
  and Federal.

* WHEN...Until 1 AM MDT Tuesday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow could significantly reduce visibility. The hazardous 
  conditions could impact the Monday evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

WYZ110-114-115-200500-
/O.CON.KCYS.WW.Y.0029.000000T0000Z-210420T0500Z/
North Snowy Range Foothills-Snowy Range-Laramie Valley-
Including the cities of Arlington, Elk Mountain, Centennial, 
Albany, Laramie, and Bosler
828 PM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 PM MDT THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 
  inches, with 6 to 10 inches for the Snowy Range. Winds gusting 
  as high as 35 mph.

* WHERE...Southeast Wyoming and portions of South Central Wyoming
  including Arlington, Laramie, and Centennial.

* WHEN...From 9 AM to 11 PM MDT Monday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow could significantly reduce visibility. The hazardous 
  conditions could impact the Monday evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$
780 
WWUS45 KCYS 200446
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
1046 PM MDT Mon Apr 19 2021

...STRONG COLD FRONT WILL BRING MUCH COLDER TEMPERATURES AND
ACCUMULATING SNOW THROUGH THIS EVENING...

WYZ110-114-115-200600-
/O.EXP.KCYS.WW.Y.0029.000000T0000Z-210420T0500Z/
North Snowy Range Foothills-Snowy Range-Laramie Valley-
Including the cities of Arlington, Elk Mountain, Centennial, 
Albany, Laramie, and Bosler
1046 PM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY WILL EXPIRE AT 11 PM MDT THIS
EVENING...

Snow has continued to taper off north to south. A few light snow
showers through the next few hours are not out of the question.

$$

WYZ116-200900-
/O.CON.KCYS.WS.W.0012.000000T0000Z-210420T0900Z/
South Laramie Range-
Including the cities of Buford, Pumpkin Vine, and Vedauwoo
1046 PM MDT Mon Apr 19 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 3 AM MDT
TUESDAY...

* WHAT...Heavy snow and blowing snow expected. Total snow 
  accumulations of 5 to 8 inches. Winds gusting as high as 40 
  mph will created areas of drifting snow.

* WHERE...South Laramie Range including the Interstate 80 Summit 
  and Vedauwoo.

* WHEN...From 9 AM Monday to 3 AM MDT Tuesday.

* IMPACTS...Travel could be very difficult with snow covered
  roads. Blowing snow could significantly reduce visibility. The
  hazardous conditions could impact the Tuesday morning commute
  between Cheyenne and Laramie.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

NEZ020-054-WYZ117>119-200700-
/O.CON.KCYS.WW.Y.0029.000000T0000Z-210420T0700Z/
Banner County-Kimball County-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
Including the cities of Harrisburg, Kimball, Whitaker, Federal, 
Horse Creek, Cheyenne, and Pine Bluffs
1046 PM MDT Mon Apr 19 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 1 AM MDT
TUESDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 
  inches, with 6 to 10 inches for the Snowy Range. Winds gusting 
  as high as 35 mph.

* WHERE...Southeast Wyoming and portions of South Central 
  Wyoming including Cheyenne, Kimball, Pine Bluffs, Harrisburg, 
  Whitaker, and Federal.

* WHEN...Until 1 AM MDT Tuesday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing snow
  could significantly reduce visibility. The hazardous conditions
  could impact the Tuesday morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$
058 
WWUS45 KCYS 200810
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
210 AM MDT Tue Apr 20 2021

WYZ116-200915-
/O.CAN.KCYS.WS.W.0012.000000T0000Z-210420T0900Z/
South Laramie Range-
Including the cities of Buford, Pumpkin Vine, and Vedauwoo
210 AM MDT Tue Apr 20 2021

...WINTER STORM WARNING IS CANCELLED...

Steady snow has ended across the Interstate 80 Summit and
surrounding area early this morning. Therefore, the Winter Storm
Warning has been cancelled. Additional snow showers are possible
this afternoon, but little or no additional snow accumulations are
expected into this evening. 

$$

Nearby

Winter Storm Warnings in Wyoming, 2021Every winter storm 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.