Alert archive / Nebraska / Winter Weather Advisories in 2021

Winter Weather Advisory 21, NWS Cheyenne, WY

February 27, 2021Dawes County, Sioux County, Nebraska; Albany County, Carbon County, Wyoming

NWS Cheyenne, WY issued this winter weather advisory at Feb 27, 2021, 1:00 PM MST for Dawes County, Sioux County, Nebraska; Albany County, Carbon County, Wyoming. It took effect at Feb 27, 2021, 4:32 PM MST. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued
Feb 27, 2021, 1:00 PM MST (20:00 UTC)
In effect from
Feb 27, 2021, 4:32 PM MST
Expired
Feb 28, 2021, 5:00 AM MST
In force
12 hr
Issued by
NWS Cheyenne, WY

Counties Dawes County, NE, Sioux County, NE, Albany County, WY, Carbon County, WY

The radar

The Cheyenne radar (KCYS), 110 km from the middle of the area, began a volume at 19:57 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

Rapid City, SD (KUNR), launched 12:00Z, 8.0 hours before the alert went out and 269 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, Rapid City, SD at 12:00Z on 2021-02-27Temperature 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, Rapid City, SD at 12:00Z on 2021-02-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939587897117Sfc1 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
2432 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
81 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

709 
WWUS45 KCYS 272000
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
100 PM MST Sat Feb 27 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 AM MST SUNDAY...

NEZ002-095-281200-
/O.NEW.KCYS.WW.Y.0021.210228T0000Z-210228T1200Z/
Dawes-North Sioux-
Including the cities of Chadron, Chadron St Park, and Harrison
100 PM MST Sat Feb 27 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 AM MST SUNDAY...

* WHAT...Snow and blowing snow expected. Total snow accumulations
  of 1 to 4 inches, heaviest along the Pine Ridge.

* WHERE...North Sioux County and Dawes County including Chadron
  and Harrison. 

* WHEN...From 5 PM this afternoon to 5 AM MST Sunday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing snow
  will reduce visibilities at times.

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.

&&

$$
3 follow-up statements
980 
WWUS45 KCYS 272031
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
131 PM MST Sat Feb 27 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 AM MST SUNDAY...

NEZ002-095-281200-
/O.CON.KCYS.WW.Y.0021.210228T0000Z-210228T1200Z/
Dawes-North Sioux-
Including the cities of Chadron, Chadron St Park, and Harrison
131 PM MST Sat Feb 27 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON
TO 5 AM MST SUNDAY...

* WHAT...Snow and blowing snow expected. Total snow accumulations
  of 1 to 4 inches, heaviest along the Pine Ridge. Winds gusting
  to 25 mph.

* WHERE...North Sioux County and Dawes County including Chadron
  and Harrison. 

* WHEN...From 5 PM this afternoon to 5 AM MST Sunday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing snow
  will reduce visibilities at times.

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.

&&

$$
343 
WWUS45 KCYS 272332
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
432 PM MST Sat Feb 27 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 AM MST SUNDAY...

WYZ110-281200-
/O.EXB.KCYS.WW.Y.0021.210227T2332Z-210228T1200Z/
North Snowy Range Foothills-
Including the cities of Arlington and Elk Mountain
432 PM MST Sat Feb 27 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM MST SUNDAY...

* WHAT...Snow and blowing snow. Additional snow accumulations of 
  up to one inch. Winds gusting as high as 45 mph.

* WHERE...The I-80 corridor Arlington to Elk Mountain, between
  Rawlins and Laramie.

* WHEN...Until 5 AM MST Sunday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing snow
  could significantly reduce visibility, down to a quarter mile at
  times.


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.

&&

$$

NEZ002-095-281200-
/O.CON.KCYS.WW.Y.0021.210228T0000Z-210228T1200Z/
Dawes-North Sioux-
Including the cities of Chadron, Chadron St Park, and Harrison
432 PM MST Sat Feb 27 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 AM MST
SUNDAY...

* WHAT...Snow and blowing snow expected. Total snow 
  accumulations of 1 to 4 inches, heaviest along the Pine Ridge. 
  Winds gusting to 25 mph.

* WHERE...North Sioux County and Dawes County including Chadron 
  and Harrison.

* WHEN...From 5 PM this afternoon to 5 AM MST Sunday.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow will reduce visibilities at times.

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.

&&

$$

Braun
797 
WWUS45 KCYS 281157
WSWCYS

URGENT - WINTER WEATHER MESSAGE
National Weather Service Cheyenne WY
457 AM MST Sun Feb 28 2021

NEZ002-095-281300-
/O.EXP.KCYS.WW.Y.0021.000000T0000Z-210228T1200Z/
Dawes-North Sioux-
Including the cities of Chadron, Chadron St Park, and Harrison
457 AM MST Sun Feb 28 2021

...WINTER WEATHER ADVISORY WILL EXPIRE AT 5 AM MST EARLY THIS
MORNING...

Periods of snow will continue this morning. However, any
additional accumulations are expected to be light. Travel will
remain hazardous due to icy and snow covered roads. 

$$

WYZ110-281300-
/O.EXP.KCYS.WW.Y.0021.000000T0000Z-210228T1200Z/
North Snowy Range Foothills-
Including the cities of Arlington and Elk Mountain
457 AM MST Sun Feb 28 2021

...WINTER WEATHER ADVISORY WILL EXPIRE AT 5 AM MST EARLY THIS
MORNING...

Blowing snow has ended. However, travel may remain hazardous due
to slick spots on roadways. 

$$

CLH

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 27, 3:06 AM MSTHigh Wind WatchCYSAlbany, Carbon, Laramie, Platte24 hr

Nearby

Winter Weather Advisories in Nebraska, 2021Winter Weather Advisories in Wyoming, 2021Every winter weather advisory 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.