Periods of heavy snow blanket and freezing drizzle covered the ground across portions of southeast Wyoming. Freezing drizzle of a few hundredths of an inch coated surfaces and roadways across the city of Cheyenne.
Every event with a place to put it; 9 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CYS wrote it up.
Periods of heavy snow blanket and freezing drizzle covered the ground across portions of southeast Wyoming. Freezing drizzle of a few hundredths of an inch coated surfaces and roadways across the city of Cheyenne.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Cheyenne, WY wrote its last area forecast discussion before the first event at Nov 16, 1:08 PM MST, 3 hours 52 minutes earlier.
Area Forecast Discussion
National Weather Service Cheyenne WY
108 PM MST Fri Nov 16 2018
.SHORT TERM...(This evening through Saturday Night)
Issued at 110 PM MST Fri Nov 16 2018
Forecast challenges deal with snow onset and accumulation amounts
as a strong cold front moves into the area from the north.
Currently...Cold front lays across southern Montana this
afternoon. Cooling cloud tops along and behind the front at a
west northwest jet max near 100kts moves into southern Montana.
Area METARS across southern Montana reporting snow across
southwestern Montana. Sheridan just started reporting rain the
past hour, so the front is slowly making its way south this
afternoon. Pre frontal trough lays along a line from Alliance to
Wheatland to Casper. Starting to see echoes developing over the
northern Panhandle on our radar. Really doubt anything hitting the
ground though as Chadron observation reporting a 30 degree T/TD
spread.
Front has slowed down from forecasts 24 hours ago. Do not think
the snow will get going in Converse County until after 00Z this
evening. New guidance continues to show more energy across western
Wyoming as the shortwave drops southeast. Would like to see
cooling cloud tops to corroborate this, but so far, not seeing it
across northwestern Wyoming early this afternoon.
Timing wise...look for snow to begin across Converse County around
00Z...spreading southward fairly quickly. Northern Carbon and
Albany Counties likely to see good snowfall around 11PM tonight
with our southern counties getting into the action by 3AM.
In an earlier update, did add the Sierra Madre Range into the
Snow Advisory. WPCs new two day snow total suggests maybe an
upgrade to a warning for them. Evening shift will need to monitor
closely the SNOTELS out there for possible upgrades.
Still thinking Laramie will be shadowed some with downsloping low
level flow and have held off on any upgrades for the Laramie
Valley at this time. Soundings continue to show an easterly wind
right off the surface that generally means less snow for them out
there.
Best snow accumulations still look like 3AM through 3PM Saturday.
Which will really impact travel on Interstate 80 along and west of
the Laramie Range. Folks traveling from Cheyenne to Laramie
Saturday likely to be impacted by heavy snow over the Summit.
Snow ends from north to south Saturday evening with all counties
likely ending by 11PM. For now...will keep headlines as they are
and see what happens with the timing of the front later this
afternoon.
.LONG TERM...(Sunday through Thursday)
Issued at 300 AM MST Fri Nov 16 2018
There is good model/ensemble consensus depicting a upper ridge over
the western CONUS and upper trough over the eastern CONUS through
midweek, with prevailing northwest flow aloft. The ridge shifts
east across the Rockies and high plains Thursday, with winds aloft
backing to the southwest. A little moisture may spread northeast
over the southern WY mountains Thursday and produce isolated snow
showers. Otherwise, the extended forecast will remain dry. Winds
will be breezy Wednesday and Thursday west of I-25. Temperatures
Sunday will be 3 to 5 degrees cooler than MOS guidance due to the
snowpack from Saturday/s winter storm. Temperatures will moderate
to above seasonal normals beginning Monday.
&&
.AVIATION...(For the 18Z TAFS through Saturday morning)
VFR through late this afternoon with increasing cloudiness. West
winds will gust up to 30 knots across the area through early this
afternoon before winds shift into the north and diminish through
tonight. Conditions will deteriorate tonight from north to south
across the area, with MVFR CIGS expected between 00z to 06z late
this evening. Widespread IFR to LIFR VIS and CIGS expected mainly
after 05z and by early Saturday morning in moderate snowfall. These
conditions will linger through Saturday.
&&
.FIRE WEATHER...
Issued at 110 PM MST Fri Nov 16 2018
Accumulating snow expected across much of southeast Wyoming and
Nebraska Panhandle over the next 24 to 36 hours as a cold front
moves through the area. Mountains of southeast Wyoming likely to
see close to a foot of snow with lower elevations seeing 4-5
inches across southeast Wyoming and the western Nebraska
Panhandle FWZs. Colder temperatures through Sunday with well above
critical afternoon humidity expected. Fire weather concerns
minimal through Monday...but we do go into a prolonged dry and
warmer weather pattern for most of next week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory from 5 PM this afternoon to 8 PM MST
Saturday for WYZ101-102-107>109-112-113-115-118-119.
Winter Storm Warning from 5 PM this afternoon to 8 PM MST
Saturday for WYZ103>106-110-114-116-117.
NE...Winter Weather Advisory from 5 PM this afternoon to 8 PM MST
Saturday for NEZ019-020-054-095-096.
&&
SHORT TERM...GCC
LONG TERM...MJ
AVIATION...TJT
FIRE WEATHER...GCCHazardous Weather Outlook National Weather Service Cheyenne WY 241 AM MST Fri Nov 16 2018 NEZ002-003-021-055-WYZ111-112-170945- Dawes-Box Butte-Morrill-Cheyenne-Southwest Carbon County- Sierra Madre Range- 241 AM MST Fri Nov 16 2018 This hazardous weather outlook is for portions of western Nebraska and south central Wyoming. .DAY ONE...TONIGHT Snow Showers will increase late this evening ahead of an approaching winter storm. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Winter Weather Advisory in effect from 5 pm Friday through 8 pm Saturday. Periods of snow, heavy at times, will develop over the area late Friday and early Saturday morning. Travel will be difficult with icy and snow packed roads. Very cold temperatures will continue through the weekend and early next week with wind chills in the single digits. .Spotter information statement... Spotter activation will not be needed. Spotters are encouraged to report snowfall amounts to the National Weather Service. WYZ103>105-110-114-116-117-170945- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-North Snowy Range Foothills-Snowy Range- South Laramie Range-South Laramie Range Foothills- 241 AM MST Fri Nov 16 2018 This hazardous weather outlook is for portions of south central Wyoming and southeast Wyoming. .DAY ONE...TONIGHT Snow Showers will increase late this evening ahead of an approaching winter storm. Strong winds will increase this morning with gusts between 50 and 55 mph possible. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY .Spotter information statement... Spotter activation will not be needed. Spotters are encouraged to report snowfall amounts to the National Weather Service. NEZ019-020-054-095-096-WYZ101-102-170945- Scotts Bluff-Banner-Kimball-North Sioux-South Sioux- Converse County Lower Elevations-Niobrara County- 241 AM MST Fri Nov 16 2018 This hazardous weather outlook is for portions of western Nebraska and east central Wyoming. .DAY ONE...TONIGHT Snow Showers will increase late this evening ahead of an approaching winter storm. Snow Showers will increase late this evening ahead of an approaching winter storm. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Winter Weather Advisory in effect from 5 pm Friday through 8 pm Saturday. Periods of snow, heavy at times, will develop over the area late Friday and early Saturday morning. Travel will be difficult with icy and snow packed roads. Very cold temperatures will continue through the weekend and early next week with wind chills in the single digits. .Spotter information statement... Spotter activation will not be needed. Spotters are encouraged to report snowfall amounts to the National Weather Service. WYZ107>109-113-115-118-119-170945- East Platte County-Goshen County-Central Carbon County- Upper North Platte River Basin-Laramie Valley- Central Laramie County-East Laramie County- 241 AM MST Fri Nov 16 2018 This hazardous weather outlook is for portions of south central Wyoming and southeast Wyoming. .DAY ONE...TONIGHT Snow Showers will increase late this evening ahead of an approaching winter storm. Snow Showers will increase late this evening ahead of an approaching winter storm. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Winter Weather Advisory in effect from 5 pm Friday through 8 pm Saturday. Periods of snow, heavy at times, will develop over the area late Friday and early Saturday morning. Travel will be difficult with icy and snow packed roads. Very cold temperatures will continue through the weekend and early next week with wind chills in the single digits. .Spotter information statement... Spotter activation will not be needed. Spotters are encouraged to report snowfall amounts to the National Weather Service. WYZ106-170945- Central Laramie Range and Southwest Platte County- 241 AM MST Fri Nov 16 2018 This hazardous weather outlook is for portions of southeast Wyoming. .DAY ONE...TONIGHT Snow Showers will increase late this evening ahead of an approaching winter storm. Snow Showers will increase late this evening ahead of an approaching winter storm. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Winter Storm Warning in effect from 5 pm Friday through 8 pm Saturday. Periods of snow, heavy at times, will develop over the area late Friday and early Saturday morning. Travel will be difficult with icy and snow packed roads. Very cold temperatures will continue through the weekend and early next week with wind chills in the single digits. .Spotter information statement... Spotter activation will not be needed. Spotters are encouraged to report snowfall amounts to the National Weather Service.
The national radar mosaic for the moment the first event began.
8 heavy snow, 1 winter storm. Local standard time, as filed.
Heavy snow reports ranging from six to eight inches across the portion of the high plains with areas along the foothills reporting upwards of a foot of new snow.
Observation site at Medicine Bow measured snow water equivalent of 1.10 inches with a derived ratio of 15 inches to 1 with an estimated value of snowfall of 15.1 inches.
Observer in Shirley Basin measured six and a half inches of snowfall. Additional snowfall report came in later for Medicine Bow with eight inches of snowfall measured.
Observer in Elk Mountain measured six and a half inches of snowfall.
Report received of measured snowfall of twelve inches twenty miles south of Glenrock.
Official measured snowfall up to eight inches in La Grange.
Official measured ten inches of snowfall across the city of Wheatland.
Crow Creek observation site at elevation 8330 feet had a snow water equivalent of 0.3 inches with a snow to liquid ratio of 20 to 1 used for snowfall total of 6.0 inches.
Crow Creek observation site at elevation 8330 feet had a snow water equivalent of 0.3 inches with an applied snow to liquid ratio of 20 to 1 for a snowfall total of 6.0 inches. In addition, a Wyoming Department of Transportation sensor along Interstate 80 near Vedauwoo measured a 56 mph non-thunderstorm wind gust for treacherous travel over the Interstate 80 Summit.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2018Every state in 2018This day in weather historyWarnings in Wyoming, November 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 787965, 787966, 787967, 787968, 787969, 787970, 787971, 787972, 799352.