A cold front swept across Wyoming and brought prefrontal high wind to the wind prone areas around Casper. Maximum wind gusts of 78 and 65 mph occurred along Wyoming Boulevard and Hat Six Road, respectively.
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The episode as NWS RIW wrote it up.
A cold front swept across Wyoming and brought prefrontal high wind to the wind prone areas around Casper. Maximum wind gusts of 78 and 65 mph occurred along Wyoming Boulevard and Hat Six Road, respectively.
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 9, 4:32 PM MST, 44 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 432 PM MST Mon Jan 9 2023 .SHORT TERM...(This Afternoon through Tuesday Night) Issued at 259 PM MST Mon Jan 9 2023 The leading edge of incoming Pacific moisture has reached far west Wyoming this afternoon. Deeper moisture overspreads areas along and west of the Continental Divide Monday evening and persists overnight. Moisture content is relatively impressive and leads to solid advisory storm totals despite limited instability and marginal orographics with 700mb wind only 20-25kts. Initial mid- level southwest flow should favor enhanced snowfall in the western valleys, particularly Jackson Hole, before the the flow veers to the west early Tuesday morning. Temperatures aloft are a bit warm for favored dendritic growth, but again, believe the deep moisture will still lead to significant snowfall. Also, there is some hint of jet coupling through 06Z/Tuesday, which also serves to enhance snowfall. East of the Divide, west-southwest 700mb wind of 40-50kts leads to high wind around Casper Monday night. Locations on the south and east sides of Casper are favored for strong winds to begin Monday evening and peak just prior to sunrise Tuesday. Have also opted to issue High Wind Warning for the Lander Foothills and Zone 19, but confidence is not great with regard to these winds materializing in Lander and Jeffrey City. However, Wyoming Highway 28 over Red Canyon and US 287 over Beaver Rim will both be impacted by the strong gusts. The cloud cover and increasing wind provides for one of the warmer nights, even in the coldest interior basins. The deeper moisture across the west begins to spread into southwest and even far northern Wyoming Tuesday morning. Jet support should aid a brief period of light snow along I-80, and a weak northerly surface boundary could enhance snow after sunrise in the northern Bighorn Basin. Therefore, adjustments were made to increase precipitation chances in these two locales. Moisture and dynamics shift east of the region by midday Tuesday. Snow subsides briefly in the west during the afternoon, while the quick-shot of snow in the north exits to the east. The warmer start to the day coupled with increased wind should boost temperatures for all areas Tuesday. The snow-covered interior basins should approach 30-32F for the first time this year. The break in the snow is short-lived as moisture returns to the southwest toward sunset Tuesday as a second shortwave takes shape to our south Tuesday night. This wave should swing moisture northward into all but the far north Tuesday night into Wednesday morning. With confidence increasing in this solution, precipitation chances were increased in these areas. At this time, it appears weak upslope flow favoring central Wyoming will likely hold at bay the best chance for accumulating snow until after 12Z/Wednesday. .LONG TERM...(Wednesday through Monday) Issued at 259 PM MST Mon Jan 9 2023 Wednesday will start off with widespread precipitation across the forecast area in response to a low tracking across northern Colorado and a trough moving across northern Wyoming. This calls for accumulating snow across western, southern, and central Wyoming. Most areas in the north, such as the Bighorn Basin and Johnson County will see only very light amounts with this pattern. There will also be strong winds across southern Wyoming from Lincoln to Sweetwater counties and into the South Pass to Casper corridor. These winds will not be nearly as strong as Tuesday, but gusts of 30 to 35 mph are still expected. Temperatures will also moderate a bit as the cold pool will be broken up and cloud cover will help minimize nighttime cooling. Late Wednesday night will see a ridge moving into the forecast area with any lingering showers exiting the area early Thursday. There will be gusty winds again Thursday afternoon along the mountains and from South Pass to Fremont and southern Johnson counties. It will be mainly dry through late Saturday, and then a new trough will begin a push into the west for the next round of accumulating snow on Sunday and Monday. Temperatures will be closer to normal values for the latter part of the forecast period. Unfortunately, with the heavy snowpack in the Wind River Basin, the temperatures could again decide to stay on the low side. Expect the development of afternoon gusty winds Saturday to Monday in the usual wind prone locations, but these are likely to be typical southwest winds. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 430 PM MST Mon Jan 9 2023 West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals. Light snow has began to fall across the far west late this afternoon. Deeper moisture arrives soon after sunset Monday with conditions deteriorating to LIFR/IFR at KJAC, KPNA, and KBPI by 03Z/Tuesday. A prolonged period of moderate snow occurs overnight before the moisture plume shifts east around 16Z/Tuesday. Jet support and a southeast shift in the moisture provides KRKS with a shot of light snow and IFR between about 12Z-16Z/Tuesday. Another wave of moisture arrives late in the period across the south. Potential impacts are for another round of light snow and sub-VFR conditions late Tuesday. Mountains frequently obscured after 23Z/Monday. East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals. VFR conditions at all terminals through at least 12Z/Tuesday. Strong westerly flow aloft may push light snow to at or near both KCOD and KLND between 13Z-18Z/Tuesday with KCOD seeing the better chance. KCPR to keep a southwest surface wind 20-35kts through the period with some increase noted late tonight. This wind does fade Tuesday afternoon. KCOD to again see west-southwest 10-18kt wind tonight. Have added low-level wind shear to KLND where downsloping wind on the east slopes of the Wind River Range will create some challenges. Cloud cover decreases and mid-level ceilings rise a bit Tuesday afternoon ahead of a secondary wave set to arrive Tuesday night. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .FIRE WEATHER... Issued at 259 PM MST Mon Jan 9 2023 Two separate rounds of wintry weather will impact the region through Wednesday. The first of these storms produces widespread accumulating snow along and west of the Continental Divide late Monday afternoon through mid-morning Tuesday. East of the Divide, downsloping west-southwest wind increases in the lee of the Wind River Range and across Natrona County. Frequent gusts 40 to 60 mph are likely tonight and Tuesday morning before the storm begins to exit the state. The last salvo from the storm could be a brief period of light snow over the northern Bighorn Basin and the Bighorn Mountains Tuesday morning into early afternoon. By Tuesday night, the second storm system begins to take shape to our south. This storm spreads wrap-around moisture into southern and central Wyoming late Tuesday night and Wednesday morning. Preliminary indications are that light accumulations of 1 to 2 inches are likely in central and southern Wyoming with higher totals in the mountains. The end of the week pattern indicates a warmer, drier, and less windy weather for most areas as an upper-ridge sets up over the region. After a few warmer days, the snow-covered interior basins will return to below normal temperatures Thursday and Friday. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 11 AM MST Tuesday for WYZ001- 012>015-023>025. High Wind Warning from 5 AM to 2 PM MST Tuesday for WYZ018. High Wind Warning until 2 PM MST Tuesday for WYZ019-020. && SHORT TERM...CNJ LONG TERM...Swanson AVIATION...CNJ FIRE WEATHER...CNJ
Hazardous Weather Outlook National Weather Service Riverton WY 317 PM MST Mon Jan 9 2023 WYZ001>020-022>030-101400- 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- 317 PM MST Mon Jan 9 2023 ...Winter Weather Advisories for much of western Wyoming Monday Afternoon through Late Tuesday Morning... ...High Wind Warnings for Portions of Central Wyoming Monday Night into Tuesday afternoon... This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...This afternoon and tonight. This Afternoon and Tonight...Light to moderate snow with widespread 6 to 12 inch snow totals in the mountains. Valley locations can expect 3 to 5 inches. Strong wind increases in Natrona County and southeast Fremont County Monday evening with wind gusts 40 to 60 mph tonight, especially on the south side of Casper. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Tuesday...Snow decreases in the west during the morning. Downsloping wind increases along the east slope of the Wind River Range with high wind likely around Red Canyon, mainly through midday. Tuesday Night and Wednesday...Additional light snowfall accumulations are forecast across western, central, and southern Wyoming. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report new snowfall totals to the National Weather Service Tuesday morning.
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2023Every state in 2023This day in weather historyWarnings in Wyoming, January 2023
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: 1076710.