Two storm systems will impact Northwest Wyoming in the coming days, resulting in much cooler and wetter conditions from Wednesday afternoon through Saturday — including heavy snow for the mountains and even some snow in the valley at times.
Wednesday – Thursday:
Wednesday morning is starting out nice and mild but clouds will increase with isolated showers reaching the Tetons by late morning, and temperatures will not warm up much from this morning with valley highs in the mid 50s.
Showers will become more widespread on Wednesday afternoon and especially on Wednesday night as a cold front moves through. The rain/snow line will range from 7,000-8,000 ft. on Wednesday afternoon before falling to 6,000-7,000 ft. on Wednesday night/Thursday morning, so we could see some snowflakes falling in the town of Jackson on Thursday morning with even some slushy accumulations in the GTNP valley (especially above 6,500 ft.).
The higher elevations of the Tetons will pick up 5-10 inches of snow through midday Thursday. If you’re driving over Teton or Togwotee Passes on Thursday morning, or north up into Yellowstone, then expect to encounter snow and slushy roads. Conditions will largely dry out on Thursday afternoon with only a slight chance of isolated showers.
Friday – Saturday:
The second storm system will arrive on Friday morning with numerous showers expected to continue through about midday Saturday. The rain/snow line could start out as low as 6,500 ft. on Friday morning before rising to 7,000-8,000 ft. in the afternoon. A cold front will then arrive on Friday night with snow levels down to the valley floor by Saturday morning.
The higher elevations of the Tetons will pick up an additional 6-12 inches of snow on Friday-Saturday and the GTNP valley could wake up to a couple of inches of snow on Saturday morning as well. Conditions will start to dry out on Saturday afternoon with temperatures remaining chilly.
Sunday – Monday:
A drier pattern will prevail with cool temperatures on Sunday giving way to a more noticeable warm-up on Monday.
Alan Smith, Meteorologist