Another strong, moisture laden Pacific system moved into Wyoming and brought moderate to heavy snow for many areas across western and central Wyoming. In areas West of the Divide, the highest amounts fell in the Tetons where 19 inches of new snow fell at the Jackson Hole Ski Resort.
Every event with a place to put it; 13 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 strong, moisture laden Pacific system moved into Wyoming and brought moderate to heavy snow for many areas across western and central Wyoming. In areas West of the Divide, the highest amounts fell in the Tetons where 19 inches of new snow fell at the Jackson Hole Ski Resort. Other notable amounts west of the Divide included 15 inches at the Star Valley Ranch, 15 inches at Green River and 14 inches at Farson. Heavy snow also moved East of the Divide. The heaviest snow occurred in Fremont County where around a foot of new snow fell near Lander with 8 to 10 inches around Riverton. Some other amounts included 7 to 10 inches around Thermopolis and 6 to 9 inches around Casper. As a result of the snow, many roads and mountains passes were closed at times during the winter storm.
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 Jan 22, 2:05 PM MST, 1 hour 55 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 205 PM MST Sun Jan 22 2017 .Short Term...Tonight Through Wednesday Snow increasing significantly across northern Utah and southern Idaho one track to spread across southwest and west Wyoming close to model timing. Southwest winds increasing across the higher western mountains. Have issued winter storm warnings tonight through Monday for Teton and Lincoln counties. With lower snowfall amounts expected in Sublette...and western Fremont counties and across Yellowstone National Park, have gone with winter weather advisories tonight through Monday for these areas. Snow expected to move into the Absaroka mountains later tonight and have issued a winter weather advisory there which extends through Monday night as the mountains will also receive snowfall as the flow turns to the north. The turning to the north will be associated with a cold front moving south from Montana with snowfall shifting to areas east of the continental divide moving into the far north Monday afternoon spreading south across central and eastern areas Monday night and Tuesday morning. May need winter weather advisories in the Big horn mountains...in and around the Owl Creek mountains including Thermopolis. Advisories may also be needed Monday night into Tuesday morning for Fremont and Natrona counties with the greatest snowfall expected in the Lander foothills and around Casper and Casper Mountain. Colder air will spread across the west starting monday night then across the east Tuesday and Tuesday night. snowfall will likely linger across the western and northern mountains being rather light through Wednesday. cooling will continue through Wednesday with possible development of fog in the valleys and basins. Lows in the single digits to -15 in the northwest possible Tuesday night and Wednesday morning. low clouds and fog may complicate the temperature forecasts through the period. Models still have their differences with the NAM preferring more precipitation in the south with the GFS preferring central Wyoming. They do come into better agreement later Monday night and Tuesday morning. The GFS prefers snowfall behind the Montana cold front, while the NAM focuses on jet dynamics in the southwest. .Long Term...Wednesday Night Through Sunday Still have the trough and cold air aloft over the area Wednesday night and Thursday. Models hint at some very light snow over the mountain peaks through Thursday afternoon. Otherwise dry Thurs at the lower elevations. Cold day for all places with the cold air aloft over the region. Then Thursday night the upper ridge moves toward the region with warming temperatures aloft. Dry weather is expected Thurs night and temps will head below zero in all the snow covered valleys and basins with a clear sky expected. This sharp ridge axis will keep a northerly flow aloft over the area Friday and Saturday. A more northwest flow aloft is forecast for next Sunday. Dry weather for Friday through Sunday. The main forecast issue will be the developing basin/valley inversions and the likelihood of fog formation in the favored locations Thursday night through Sunday. The sounding profiles get more favorable with time. Once the fog or stratus forms, it may take much of the day to break up, or in some cases it may not break up at all. As temps warm in the mountains and mixed locations, the valleys and basins will remain cold with lows at night below zero. However, the fog or stratus will prevent those places from getting extremely cold, but it hampers temps rebounding during the day if it does break out later in the day. && .Aviation.../00Z Issuance/ WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES VFR conditions will prevail at the terminal sites through 02Z. Snow will occur over the mountains with areas of MVFR conditions through 02Z. After 02Z, snow will increase in coverage with MVFR to IFR conditions becoming widespread by 05Z. These conditions will continue through 00Z Tue. Expect mountains to be obscured through the period. Check the latest terminal forecasts for more details. EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES VFR conditions to prevail at most sites through 00Z Tuesday. In the north, a cold front will move into that area after 15Z Monday. Clouds will be lowering with light snow developing by 19Z in the north. Expect MVFR conditions to prevail in the north after 19Z Mon. A gusty wind at KCPR terminal site through the period. Areas of LLWS can also be expected through 12Z at a few of the terminal sites. Check the latest terminal forecasts for more details. && .Fire Weather... Snow increasing significantly across northern Utah and southern Idaho one track to spread across southwest and west Wyoming close to model timing. Southwest winds increasing across the higher western mountains. Have issued winter storm warnings tonight through Monday for Teton and Lincoln counties. With lower snowfall amounts expected in Sublette...and western Fremont counties and across Yellowstone National Park, have gone with winter weather advisories tonight through Monday for these areas. Snow expected to move into the Absaroka mountains later tonight and have issued a winter weather advisory there which extends through Monday night as the mountains will also receive snowfall as the flow turns to the north. The turning to the north will be associated with a cold front moving south from Montana with snowfall shifting to areas east of the continental divide moving into the far north Monday afternoon spreading south across central and eastern areas Monday night and Tuesday morning. May need winter weather advisories in the Big horn mountains...in and around the Owl Creek mountains including Thermopolis. Advisories may also be needed Monday night into Tuesday morning for Fremont and Natrona counties with the greatest snowfall expected in the Lander foothills and around Casper and Casper Mountain. Colder air will spread across the west starting monday night then across the east Tuesday and Tuesday night. snowfall will likely linger across the western and northern mountains being rather light through Wednesday. cooling will continue through Wednesday with possible development of fog in the valleys and basins. Lows in the single digits to -15 in the northwest possible Tuesday night and Wednesday morning. low clouds and fog may complicate the temperature forecasts through the period. Models still have their differences with the NAM preferring more precipitation in the south with the GFS preferring central Wyoming. They do come into better agreement later Monday night and Tuesday morning. The GFS prefers snowfall behind the Montana cold front, while the NAM focuses on jet dynamics in the southwest. Mixing heights will be low with stratus...fog...snowfall across the area with poor smoke dispersal through mid week. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 11 PM this evening to 5 AM MST Tuesday for WYZ002. Winter Storm Warning from 5 PM this afternoon to 5 PM MST Monday for WYZ012-013-023-024-027. Winter Weather Advisory from 5 PM this afternoon to 5 PM MST Monday for WYZ001-014-015-025-026. && SHORT TERM...C.Baker LONG TERM...AR AVIATION...AR FIRE WEATHER...C.Baker
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 247 PM MST SUN JAN 22 2017 WYZ001>020-022>030-231100- 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- 247 PM MST SUN JAN 22 2017 ...WINTER STORM WARNINGS AND ADVISORIES ARE IN EFFECT FOR WESTERN WYOMING TONIGHT THROUGH MONDAY AFTERNOON... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SNOW WILL OCCUR IN WESTERN WYOMING TONIGHT. SNOW WILL BE MODERATE TO HEAVY AT TIMES. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY MONDAY...PERIODS OF MODERATE TO HEAVY SNOW ACROSS THE WEST MONDAY MORNING...THEN TAPERING OFF MONDAY AFTERNOON. SOME SNOW WILL OCCUR IN SOUTHERN WYOMING MONDAY. MONDAY NIGHT AND TUESDAY...LIGHT TO MODERATE SNOW WILL OCCUR EAST OF THE CONTINENTAL DIVIDE MONDAY NIGHT THROUGH TUESDAY MORNING. FRIDAY AND SATURDAY...AREAS OF DENSE MORNING FOG POSSIBLE IN THE CENTRAL BASINS AND WESTERN VALLEYS. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AMOUNTS.
Special Weather Statement National Weather Service Riverton WY 230 PM MST Sun Jan 22 2017 WYZ003>011-231100- 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- Including the cities of...Cody...Meeteetse...Thermopolis... Worland...Buffalo...Kaycee 230 PM MST Sun Jan 22 2017 ...Periods of snow Monday afternoon into Tuesday morning... A weather system will move across the area Monday afternoon through Tuesday morning along with a cold front passage. Snow will develop early Monday afternoon in the north and this snow will spread south. Periods of snow will occur Monday night into Tuesday morning. Snow will be ending early Tuesday afternoon. Snowfall amounts will range from 2 to 4 inches with locally 6 inches in the favored upslope areas around Thermopolis and in Bighorn mountains. Only 1 to 2 inches of snow is expected in Big Horn county. Expect road conditions to become slick or snow packed Monday night through Tuesday morning. WYZ016>018-020-022-231100- Upper Wind River Basin-Wind River Basin-Lander Foothills- Natrona County Lower Elevations-Casper Mountain- Including the cities of...Dubois...Riverton...Shoshoni...Lander... Casper 230 PM MST Sun Jan 22 2017 ...Periods of snow Monday night into Tuesday morning... A weather system will move across the area Monday night and Tuesday morning along with a cold front passage. Snow will develop late Monday afternoon or early Monday evening and continue into Tuesday morning. Snow will be ending Tuesday afternoon. Snowfall amounts will range from 2 to 4 inches with locally 6 inches in the favored upslope areas around Lander and the foothills of Casper mountain. Expect road conditions to become slick or snow packed Monday night through Tuesday morning. WYZ019-028>030-231100- Green Mountains and Rattlesnake Range- Rock Springs and Green River-Flaming Gorge-East Sweetwater County- Including the cities of...Jeffrey City...Rock Springs... Green River...Wamsutter 230 PM MST Sun Jan 22 2017 ...Periods of snow tonight through Monday night... A weather system will bring periods of snow to these areas tonight through Monday night. Total snowfall of 2 to 4 inches is expected with as much as 6 inches in the Green Mountains and Rattlesnake Range. Expect road conditions to become slick or snow packed later tonight through Monday night. This includes Interstate 80 in Sweetwater county.
The national radar mosaic for the moment the first event began.
13 winter storm. Local standard time, as filed.
At the Jackson Hole Ski Resort, 19 inches of new snow was measured.
The Teton County sheriff reported 6 to 8 inches of snow around the city of Jackson. In Moose, 9 inches of new snow fell.
Heavy snow fell throughout the Star Valley. Snowfall amounts ranged from 8.5 inches at Afton to 19.5 inches 5 miles north-northeast of Thayne.
Heavy snow fell through most of the Salt and Wyoming Range. Some of the highest amounts included 16 inches at the Willow Creek SNOTEL and 14 inches at the Kelly Ranger Station SNOTEL.
New snow generally ranged from 8 to 10 inches. At Pinedale, 10.1 inches of new snow fell.
Snowfall amounts in the Upper Green River Basin ranged from 8 inches at Big Piney to 14 inches at Farson.
Heavy snow fell in the southern portion of Lincoln County. Some of the highest amounts included 12 inches at Cokeville and 11 inches at Diamondville.
Trained spotters reported 12 to 15 inches around Green River. In Rock Springs, 6 to 9 inches of snow fell.
The COOP observer in Riverton reported 10.3 inches of new snow. In Hudson, there was 11 inches of new snow.
Snowfall amounts in the Green Mountains and Rattlesnake Range varied from 9 inches at Jeffrey City to 11.7 inches at Sweetwater Station.
Trained spotters measured 7 to 10 inches of new snow around the city of Thermopolis.
The observer at the Lander airport measured 10.8 inches of new snow. Across Lander, new snow ranged from 9 to 11 inches.
The observer at the Casper airport measured 8.4 inches of new snow. Snowfall amounts around the city of Casper generally ranged from 6 to 9 inches.
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, January 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: 670155, 670148, 670149, 670150, 670154, 670156, 670151, 670160, 670152, 670157, 670159, 670153, 670158.