Periodically strong gap winds developed across portions of southeast Wyoming due to strengthening pressure gradients in advance of a potent cold front.
Every event with a place to put it; 17 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.
Periodically strong gap winds developed across portions of southeast Wyoming due to strengthening pressure gradients in advance of a potent cold front.
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 Dec 3, 4:34 AM MST, 36 minutes earlier.
Area Forecast Discussion
National Weather Service Cheyenne WY
434 AM MST Sat Dec 3 2016
.SHORT TERM...(Today through Monday)
Issued at 300 AM MST Sat Dec 3 2016
Winds are the primary forecast challenge in the short term
followed by snow chances Monday.
Two systems impacting our weather in the short term. One, a low
pressure system over southern Arizona and New Mexico this morning
will track east towards the southern Plains. THis one may
effectively cut off any low level moisture from the Gulf of Mexico
from getting up this way. The other system moving into the PACNW
this morning. Pretty strong gradient behind this system with very
cold air as evidenced by all the open cell CU observed behind the
front in the southeastern Gulf of Alaska.
For today, Craig to Casper gradients continue to increase this
morning. By 12Z, 850/700mb gradients are forecast to be near
60mtrs respectively on both the GFS and NAM High Wind Products.
GFS 700mb winds at 12Z forecast at 50kts across Carbon and Albany
Counties. Thinking the current High Wind Warning is looking in
good shape and will let it ride through the morning hours.
We see a slight decrease in winds by late afternoon and overnight
before gradients again begin to increase Sunday morning after 12Z.
This could a more prolonged strong wind event as gradients remain
high (60mtrs or greater into Monday. By 09Z Monday, 700mb
gradients off the GFS approaching 73mtrs that persist through
Monday morning. Went ahead with a High Wind Watch for Sunday
morning through Monday morning to alert customers of strong wind
potential after todays wind event.
Front finally moves into western Wyoming Monday morning and into
southeast Wyoming Monday afternoon. 700mb temperatures fall from
-4C at Cheyenne Monday morning to -16 to -18C Monday afternoon
with the passage of the front. Have to agree with the GFS that
there may not be a lot of low level moisture to work with this
system due to the southern low. Best chances for heavier snow
looks to be the Snowy and Sierra Madre Ranges with this system.
.LONG TERM...(Monday night through Friday)
Issued at 300 AM MST Sat Dec 3 2016
Monday night/Tuesday...Bitterly cold air will continue to filter
into the region from the north following an arctic cold frontal
passage on Monday. Light snow associated with a passing shortwave
will move from our central counties Monday night, to near and along
the Colorado state line on Tuesday assisted by upslope northeast
winds.
Wednesday...Snow will gradually end as the flow aloft becomes
northwest and drier air filters into the region, although bitterly
cold temperatures will persist as 700 mb temperatures plunge to -22
Celsius, yielding maximum temperatures in the single digits and
teens.
Thursday...A slow warming trend will begin under northwest flow
aloft. Continued dry with limited low and mid level moisture.
Friday...As the flow aloft backs to zonal, west to east, surface lee
troughing will become more established, helping to moderate the low
levels of the atmosphere, and most locations will climb above
freezing, at least into the upper 30s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 432 AM MST Sat Dec 3 2016
Wyoming TAFS...VFR prevails. Winds gusting 30 to 35 knots from
15Z to 02Z.
Nebraska TAFS...VFR prevails. Winds gusting 23 to 26 knots from
15Z to 02Z.
&&
.FIRE WEATHER...
Issued at 300 AM MST Sat Dec 3 2016
Minimal fire weather concerns will continue through next week as
cold temperatures will remain over the area. Winds will increase
today and persist through Monday ahead of a low pressure system
that will track through the area. Accumulating snow is possible
with this system Tuesday into Wednesday next week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Warning until 3 PM MST this afternoon for WYZ106-110.
High Wind Watch from Sunday morning through Monday morning for
WYZ106-110.
NE...None.
&&
SHORT TERM...GCC
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...GCCHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 324 AM MST SAT DEC 3 2016 WYZ106-110-041030- CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY- NORTH SNOWY RANGE FOOTHILLS- 324 AM MST SAT DEC 3 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT A HIGH WIND WARNING IS IN EFFECT FROM 3 AM TO 3 PM TODAY. WINDS WILL BE SOUTHWEST AT 35 TO 45 MPH WITH GUSTS TO 60 MPH. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A HIGH WIND WATCH IS IN EFFECT FROM 8 AM SUNDAY TO 8 AM MONDAY. A STRONG COLD FRONT WILL BRING BITTERLY COLD AIR TO THE REGION MONDAY THROUGH WEDNESDAY. SNOWFALL ACCUMULATIONS ARE LIKELY AS WELL. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. WYZ101>105-107>109-111>119-041030- CONVERSE COUNTY LOWER ELEVATIONS-NIOBRARA COUNTY- NORTH LARAMIE RANGE-FERRIS/SEMINOE/SHIRLEY MOUNTAINS- SHIRLEY BASIN-EAST PLATTE COUNTY-GOSHEN COUNTY- CENTRAL CARBON COUNTY-SOUTHWEST CARBON COUNTY-SIERRA MADRE RANGE- UPPER NORTH PLATTE RIVER BASIN-SNOWY RANGE-LARAMIE VALLEY- SOUTH LARAMIE RANGE-SOUTH LARAMIE RANGE FOOTHILLS- CENTRAL LARAMIE COUNTY-EAST LARAMIE COUNTY- 324 AM MST SAT DEC 3 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL WYOMING...SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A STRONG COLD FRONT WILL BRING BITTERLY COLD AIR TO THE REGION MONDAY THROUGH WEDNESDAY. SNOWFALL ACCUMULATIONS ARE LIKELY AS WELL. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. NEZ002-003-019>021-054-055-095-096-041030- DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE- NORTH SIOUX-SOUTH SIOUX- 324 AM MST SAT DEC 3 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN NEBRASKA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A STRONG COLD FRONT WILL BRING BITTERLY COLD AIR TO THE REGION MONDAY THROUGH WEDNESDAY. SNOWFALL ACCUMULATIONS ARE LIKELY AS WELL. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. RUBIN
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 1209 AM MST SAT DEC 3 2016 WYZ115-031015- LARAMIE VALLEY- INCLUDING THE CITIES OF...BOSLER...LARAMIE 1209 AM MST SAT DEC 3 2016 ...AREAS OF DENSE FOG NEAR LARAMIE THROUGH 3 AM THIS MORNING... AT 1200 AM THIS MORNING. DENSE FOG IS BEING REPORTED AT THE LARAMIE AIRPORT. WYOMING DEPARTMENT OF TRANSPORTATION WEBCAM AT INTERSTATE 80 MILE MARKER 297 WAS ALSO SHOWING SOME FOG AS WELL. EXPECT THIS FOG TO DISSIPATE OVER THE NEXT COUPLE HOURS AS STRONG WESTERLY WINDS DEVELOP AROUND 3 AM. IN THE MEANTIME...TRAVELERS ON INTERSTATE 80 AROUND LARAMIE AND JUST WEST OF LARAMIE MAY RUN INTO PATCHY DENSE FOG THAT COULD REDUCE VISIBILITIES DOWN TO UNDER A HALF MILE AT TIMES. BE CAREFUL AND SLOW DOWN WHEN ENCOUNTERING THIS FOG. ALLOW EXTRA DISTANCE BETWEEN YOU AND THE VEHICLE IN FRONT OF YOU.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
438 AM MST SAT DEC 03 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0347 AM NON-TSTM WND GST 11 SSE HARRIS PARK 42.20N 105.21W
12/03/2016 M55 MPH PLATTE WY MESONET
WHEATLAND APRSWXNET EW8763. SUSTAINED WINDS AT 35 MPH.
0421 AM HIGH SUST WINDS 1 NNW ARLINGTON 41.60N 106.21W
12/03/2016 M40 MPH CARBON WY DEPT OF HIGHWAYS
ARLINGTON WEST WYDOT SITE. SUSTAINED WINDS OF 40 MPH FOR
ONE HOUR. PEAK WIND GUST 54 MPH AT 341 AM.
&&
GCLAYCOMThe national radar mosaic for the moment the first event began.
17 high wind. Local standard time, as filed.
The WYDOT sensor at County Road 402 measured sustained winds of 40 mph or higher, with a peak gust of 59 mph at 03/0555 MST.
A sensor 11 miles south-southeast of Harris Park measured a peak wind gust of 58 mph.
The WYDOT sensor at Arlington measured sustained winds of 40 mph or higher, with a peak gust of 61 mph at 03/0725 MST.
The WYDOT sensor at Arlington East measured sustained winds of 40 mph or higher.
The WYDOT sensor at Wagonhound measured sustained winds of 40 mph or higher.
The WYDOT sensor at Arlington measured sustained winds of 40 mph or higher, with a peak gust of 59 mph at 04/1140 MST.
The WYDOT sensor at Bordeaux measured sustained winds of 40 mph or higher, with a peak gust of 58 mph at 04/1230 MST.
The WYDOT sensor at Interstate 80 mile post 249 measured sustained winds of 40 mph or higher.
The WYDOT sensor at Cooper Cove measured sustained winds of 40 mph or higher, with a peak gust of 65 mph at 04/1615 MST.
The WYDOT sensor at Foote Creek measured sustained winds of 40 mph or higher.
The WYDOT sensor at Wagonhound measured sustained winds of 40 mph or higher.
The UPR sensor at Emkay measured sustained winds of 40 mph or higher, with a peak gust of 62 mph at 04/1745 MST.
The WYDOT sensor at Whitaker measured sustained winds of 40 mph or higher.
The WYDOT sensor at Otto Road measured sustained winds of 40 mph or higher.
The WYDOT sensor at Pumpkin Vine measured sustained winds of 40 mph or higher.
The WYDOT sensor at Wildcat Trail measured sustained winds of 40 mph or higher.
The WYDOT sensor at Bordeaux measured peak wind gusts of 59 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2016Every state in 2016This day in weather historyWarnings in Wyoming, December 2016
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: 666940, 666935, 666937, 666936, 666943, 666938, 666932, 666942, 666939, 666941, 666944, 666947, 666949, 666948, 666945, 666946, 666933.