A strong pressure gradient and strong northwest flow brought high winds to portions of northern Johnson County. At the Buffalo airport, there were several wind gusts over 58 mph including a maximum gust of 69 mph.
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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 RIW wrote it up.
A strong pressure gradient and strong northwest flow brought high winds to portions of northern Johnson County. At the Buffalo airport, there were several wind gusts over 58 mph including a maximum gust of 69 mph.
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 Riverton, WY wrote its last area forecast discussion before the first event at Dec 5, 12:42 PM MST, 8 hours 18 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 1242 PM MST Tue Dec 5 2017 .SHORT TERM...(This evening through Friday) Issued at 1230 PM MST Tue Dec 5 2017 A very large high pressure ridge along the west coast extending north well above the Arctic Circle will produce cool dry northerly flow over western and central Wyoming through the week with gradual warming. Some moisture over northern and eastern Wyoming will support some light snow showers at times over the northern Bighorn and Absaroka mountains. Cold air advection will battle areas of down slope winds producing lee side warming making the temperature forecast the forecast challenge through Friday. .LONG TERM...(Friday night through Tuesday) Issued at 1230 PM MST Tue Dec 5 2017 The extended will feature warming temps at the higher elevations and mixed areas along with colder air remaining in the basins and valleys underneath temperature inversions, given the long nights and short days for this time of year as high pressure amplifies to our west and attempts to build in from the west. Models struggle with this pattern, warming up the basins and valleys too quickly. As we remain on the front side of the ridge at the beginning of next week, another backdoor cold front will push south across the area next Monday, enabling the cold inversions to mix out before cooling off again along with cooling temps elsewhere. This next front will come through dry early next week with any moisture sliding off to the northeast of our area. && .AVIATION...(For the 00Z TAFS through 00Z Thursday) Issued at 1230 PM MST Tue Dec 5 2017 A stratocumulus deck will continue to obscure the far western mountains through the rest of this afternoon with the higher peaks poking through the deck. The cloud deck will hover around 2000 feet agl. These clouds will dissipate by sunset this evening. Otherwise, VFR conditions with variable mid-high level cloudiness are expected. Breezy west to northwest wind will occur at most locations with winds becoming more northerly east of the Divide late in the afternoon into the early evening as a weak frontal boundary pushes south across the area. Winds will continue through Wednesday, but from primarily a northwest direction east and west of the divide along with VFR conditions. && .FIRE WEATHER... Issued AT 1230 PM MST Tue Dec 5 2017 A very large high pressure ridge along the west coast extending north well above the Arctic Circle will produce cool dry northerly flow over western and central Wyoming through the week with gradual warming. Some moisture over northern and eastern Wyoming will support some light snow showers at times over the northern Bighorn and Absaroka mountains. Cold air advection will battle areas of down slope winds producing lee side warming making the temperature forecast the forecast challenge through Friday. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...Baker LONG TERM...Lipson AVIATION...Lipson FIRE WEATHER...Baker
Hazardous Weather Outlook National Weather Service Riverton WY 215 AM MST Tue Dec 5 2017 WYZ001>020-022>030-061200- Yellowstone National Park-Absaroka Mountains-Cody Foothills- North Big Horn Basin-Southwest Big Horn Basin- Southeast Big Horn Basin-Owl Creek and Bridger Mountains- Bighorn Mountains West-Bighorn Mountains Southeast- Northeast Johnson County-Southeast Johnson County- Teton and Gros Ventre Mountains-Jackson Hole- Wind River Mountains West-Wind River Mountains East- Upper Wind River Basin-Wind River Basin-Lander Foothills- Green Mountains and Rattlesnake Range- Natrona County Lower Elevations-Casper Mountain-Star Valley- Salt River and Wyoming Ranges-Upper Green River Basin Foothills- Upper Green River Basin-South Lincoln County- Rock Springs and Green River-Flaming Gorge-East Sweetwater County- 215 AM MST Tue Dec 5 2017 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
Special Weather Statement National Weather Service Riverton WY 609 PM MST Tue Dec 5 2017 WYZ010-061000- Northeast Johnson County- Including the city of Buffalo 609 PM MST Tue Dec 5 2017 ...Strong Northwest Winds Tonight... Northwest winds between 20 and 35 mph with gusts of 40 to 50 mph will be common across northern Johnson County tonight. Drivers of light or high profile vehicles are urged to use caution if traveling through this area tonight, especially along west to east orientated roadways, including Interstate 90. 21
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
There were several wind gusts over 58 mph at the Buffalo airport, including a maximum gust of 69 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2017Every state in 2017This day in weather historyWarnings in Wyoming, December 2017
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: 727977.