Western Wyoming PM Forecast
Issued on Tue January 22, 2019 6:03 PM
SituationSkies were clear and sunny this morning. This afternoon, cloud cover steadily increased in advance of the approaching storm system. At sunrise, temperatures had dropped to near zero degrees at the high elevations and the low teens at the base. During the day mountain temps rose to the low teens. Winds were from the west-northwest with fifteen to twenty mile per hour averages.
New surface hoar growth and surface faceting occurred on the snow surface with the return to colder temperatures and overnight clear skies. The snowpack remains unstable. Persistent weak snow lies under snow received in the last week. At higher elevations these persistent layers include a mix of sun crusts and surface hoar on southerly aspects and near surface facets and surface hoar on northerly aspects. At lower elevations or in areas where the snowpack is relatively shallow, the recent snow lies on a snowpack that is mostly or entirely faceted and has little strength. Today a group remotely triggered a slide from a ridge on Mt Elly. This slide may be one that another skier had reported to have taken out his skin track from an earlier meadow crossing. A remotely triggered slide was also reported in No Name Canyon to the south of the Jackson Hole Mountain Resort.
Forecast For Wednesday, January 23, 2019The incoming system will bring snowfall to the area by midnight with a few inches expected by sunrise. Steady snowfall is to continue through the daylight hours and the evening. Five to ten inches is expected by midnight with higher amounts expected in the upper elevations of the Tetons. West winds are to average near twenty to twenty-five miles per hour while mountain temperatures have highs in the mid-teens.
The general avalanche hazard is expected to remain Considerable above 7500 feet and Moderate below that elevation. At all elevations, backcountry riders and skiers have the potential to trigger slab avalanches involving persistent weak layers of snow involving surface hoar and in many areas profoundly faceted layers. These slabs could be released remotely or once a person is on a slab and finds a weak point on the slope. In addition to this existing threat(that will become more sensitive with additional loading), new wind slabs will begin to form on the current snow surface. These slabs will increase in size and sensitivity as the day progresses and are likely to be sensitive in steep terrain by the afternoon.
Trend For Thursday, January 24, 2019 AND Friday, January 25, 2019Snowfall is to taper off on Wednesday night with lingering snow showers expected on Thursday. A chance for snow continues Friday with light accumulations. Highs during the period are to be in the mid-teens on Thursday and slightly cooler on Friday. The avalanche danger will remain elevated on Thursday and then is likely to slowly decrease as the snowpack adjusts to the new loading.
SPONSORS: Box Y Ranch, Togwotee Mountain Lodge, Jackson Hole Mountain Resort, Wyoming State Trails Program, Brooks Lake Lodge, Bruce Hayse M.D., Skinny Skis, Chippy's Kitchen and Catering, Grand Targhee Resort, DeFazio Law, Eric Balog, Stewart Johnson, CPA, Grand Teton Floor & Window Coverings, Apex Real Estate and Property Management, RPK3 Law, Next Level Riding Clinics, Eco Tour Adventures, Stio, Grand Teton National Park Foundation, Teton Gravity Research, Headwall Sports, Arc'Teryx, Yostmark, Tip Top Search and Rescue, Weston Snowboards and Tower 3 Investments