Another moisture laden Pacific Storm system moved into western Wyoming on the heels of the previous storm on November 1st and brought another round of heavy snow to the western mountains of Wyoming. Over a foot of new snow fell in many of the higher elevations of the mountains with close to 2 feet in some locations.
Every event with a place to put it; 5 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 RIW wrote it up.
Another moisture laden Pacific Storm system moved into western Wyoming on the heels of the previous storm on November 1st and brought another round of heavy snow to the western mountains of Wyoming. Over a foot of new snow fell in many of the higher elevations of the mountains with close to 2 feet in some locations. Some of the more notable snowfall amounts include 23 inches at the Willow Creek SNOTEL in the Salt and Wyoming Range and Lewis Lake Divide in Yellowstone Park, 20 inches at Jackson Hole Ski Resort and 18 inches at Beartooth Lake in the Absarokas.
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 Nov 2, 10:12 PM MST, 3 hours 48 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 1112 PM MDT Thu Nov 2 2017 .SHORT TERM...This evening through Saturday night Issued at 210 PM MDT Thu Nov 2 2017 Imagery continues to show a broad longwave trof across the CONUS with a few embedded disturbances within the flow...with an embedded strong jet (100 to 130 kts)/elongated vort max across cntrl/nrn WY beginning to lift nwd...and the next much more significant embedded wave that will impact WY over swrn BC/nwrn WA coast. The SFC now has a cyclone developing across the srn Plains with a cold front just to the north of this low, stretched from another low ovr the Great Lakes to/near the low ovr the srn Plains and back up along the Front Range of CO then roughly along the Continental Divide through cntrl WY and west into ID. Most light precip activity is falling along/north of the front and is slowly decreasing in extent and intensity. Current heaviest activity occurring near or just east of the entrance region of the jet. Rest of today dynamics from the aforementioned jet across cntrl/nrn WY today/tonight will continue to give some additional lift, in addition to that of the terrain, to existing moisture across portions of cntrl/ wrn/nwrn WY. Winter Storm Warnings and Advisories continue for the Absaroka, Teton, Gros Ventre and Wind River Mountains in addition to YNP this afternoon. Snowfall decreasing significantly elsewhere and highlights have been dropped from those locations. This afternoon/evening, the jet continues to translate slowly northward, taking the better dynamics with it and leaving light areas of mainly terrain forced precipitation across nw WY under zonal flow aloft with precip ending (or already has ended) elsewhere. Friday, the upper levels begin to turn southwesterly as the BC/WA shortwave mentioned above digs swd along the PAC NW coast as far as nrn California. A srn branch of the jet will move into/across the sw CONUS on the se side of the PAC trof and into srn WY. The exit region of this srn branch of the jet and the entrance region of the exiting jet (now over MT) will begin phasing and provide increased vorticity and lift in addition to the terrain across wrn WY. With increasing EPAC moisture flowing into the FA from around the digging trof out west, excellent areas of relatively significant precipitation will be (re)breaking out. With H7 temperatures will begin on the warm side and are forecast to range from -3 to -5 deg C in the WAA regime through the Day Friday. for a while, snowfall will most likely remain above valley floor levels AOA 6500 feet at least during the day on Friday. However, moderate to heavy snow will increase in the mountains with many of these areas, such as the Teton and Gros Ventre Mountains, receiving/averaging 3 to 6 inches (or more in favored locations) of new snowfall every 6 hrs through Saturday night. A winter Storm Warning has been issued for for zones 1, 2, 12, 14, 15, and 24 (the basic mountain grouping of western Wyoming in addition to Yellowstone NP). Late overnight Friday into early Saturday morning, snow levels will drop to the valley floors as upper level temps drop with the approach of the trof itself. Advisory level snow will be increasingly probable across the Star and Jackson valleys Saturday through Saturday night. .LONG TERM...Sunday through Thursday Issued at 210 PM MDT Thu Nov 2 2017 Synopsis...The second longwave trough over the PACNW follows the track over the previous system, but quickly fills as it moves over WY by 12Z Tuesday. The remnants of this system will exit into the Central Plains by 12Z Wednesday, giving way to a shortwave ridge that will be in place through the rest of the period. Moist Pacific SW flow could return Thursday night, bringing the next round of snow to the west. Discussion...Snow will be less significant across the west with this second system, mainly due to the system quickly weakening Monday. However, snow will continue to fall before quickly ending after sunrise Tuesday. Snow will also spread across the south Sunday night with light accumulations. Some blowing snow will be possible briefly, as winds subside Sunday evening along the Wind Corridor. This activity will continue into Monday, before transitioning back to rain Monday afternoon. Chances for snow will return across the far north Monday, as the second cold front quickly sweeps through the area. Accumulations look to be light east of the Divide Sunday night into Monday, especially for southern portions that switch over to rain during the day Sunday and Monday. Apart from breezy winds in the afternoon in wind prone locations Sunday and Monday, winds will be generally light through the period. && .AVIATION...For the 06Z TAFS through 06Z Saturday Issued at 1110 PM MDT Thu Nov 2 2017 Low clouds and areas of fog will occur east of the continental divide through 18Z. Expect MVFR to IFR conditions with local LIFR conditions. VFR conditions will prevail after 21Z in these areas as the low clouds dissipate. A gusty wind will develop at KCPR airport around 18Z. West of the continental divide, snow will prevail in the mountains with a mix of rain and snow in the lower elevations of far west WY. MVFR to IFR conditions will prevail over and near the mountains and from Jackson to Afton. These conditions will continue through 06Z Saturday. In southwest WY, VFR conditions will prevail with scattered rain and snow showers. Local MVFR conditions will occur near the mountains. This includes the KPNA airport. && .FIRE WEATHER... Issued AT 210 PM MDT Thu Nov 2 2017 Fuels remain at critical levels across over Fremont, Johnson and Natrona Counties. Fire weather conditions will be relatively low through the beginning of next week as one early season winter weather system is replaced by another over the next several days. Significant precipitation (much as snowfall) is expected in the mountains west of the Divide with generally below seasonal temperatures and minimum relative humidity staying at or above 25 percent in the afternoons at all locations. Between 0.75 and 1.25 inch of liquid is expected to fall in various forms through Sunday morning. Winds, however, will be brisk in the mountains and across southern and into central Wyoming through the weekend...gusting 35 to 45 mph out of the west at times. Precipitation chances east of the Divide do not really return until later Saturday and Saturday night...and even then liquid amounts will be low, generally less than 0.10 inch. Smoke dispersion good today, becoming fair to good in the afternoons over the weekend. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 6 AM MDT Friday to 5 AM MST Sunday for WYZ001-002-012-014-015-024. && SHORT TERM...Braun LONG TERM...LaVoie AVIATION...LaVoie FIRE WEATHER...Braun
Hazardous Weather Outlook National Weather Service Riverton WY 216 PM MDT Thu Nov 2 2017 WYZ001>020-022>030-032030- 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- 216 PM MDT Thu Nov 2 2017 ...WINTER STORM WARNING FRIDAY MORNING THROUGH SATURDAY NIGHT FOR THE WESTERN MOUNTAINS... This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight. Light to occasionally moderate snow to continue in portions of northern and northwestern Wyoming. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Friday through Saturday...Significant mountain snowfall expected in the western and northwestern mountains. Strong winds from Rock Springs to Casper much of this period. Strong winds in the mountains and east slope of most mountain ranges on Saturday. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report any snowfall accumulation. Thank you.
Special Weather Statement National Weather Service Riverton WY 932 PM MDT Thu Nov 2 2017 WYZ020-031200- Natrona County Lower Elevations- Including the city of Casper 932 PM MDT Thu Nov 2 2017 Areas of fog will persist in Natrona county overnight. Visibility will be reduced to under one mile in some locations. Local freezing drizzle is possible as well. The fog may impact the morning commute on Friday. Slow down and use low beam headlights in areas of fog.
Special Weather Statement National Weather Service Riverton WY 1051 PM MDT Thu Nov 2 2017 WYZ016-031200- Upper Wind River Basin- Including the city of Dubois 1051 PM MDT Thu Nov 2 2017 Areas of fog will occur overnight. Visibility will be reduced to under one mile in some locations. Local freezing drizzle is possible as well. The fog may impact the morning commute on Friday. Slow down and use low beam headlights in areas of fog.
The national radar mosaic for the moment the first event began.
5 winter storm. Local standard time, as filed.
Over a foot of new snow fell in the higher elevations of the Absarokas. Some of the highest amounts included 18 inches at Beartooth Lake and 14 inches at Evening Star.
Heavy snow fell in portions of the Tetons. On the top of the Jackson Hole Ski Resort, 20 inches of new snow was reported. At Grand Targhee, the SNOTEL site reported 22 inches of snow.
Many of the higher elevations of Yellowstone Park saw over a foot of new snow. Some of the highest amounts included 23 inches at Lewis Lake Divide and 21 inches at Two Oceans Plateau.
The Hobbs Park SNOTEL site reported 14 inches of new snow.
Over a foot of new snow was commonplace across the higher elevations of the Salt and Wyoming Range. Some of the more notable amounts included 23 inches at Willow Creek, 21 inches at Blind Bull Summit and 20 inches at Commissary Ridge.
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, November 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: 723825, 723828, 723834, 723830, 723833.