We’ve already seen some rain showers move through Teton County on Friday morning, and we will see heavier and more widespread showers develop as the day progresses thanks to a southerly flow of subtropical moisture along with an extra “boost” from the jet stream.
Rain will continue through Friday evening before eventually tapering off after midnight on Friday night. Snow levels will range from 9,500-10,000 feet but could dip to 9,000 feet or lower briefly on Friday night. There is a chance we could see a thunderstorm on Friday afternoon as well.
Highs on Friday will top out in the upper 50s in the valley. Rain totals through Friday night will be impressive, ranging from 0.75-1.5 inches in the Tetons and 0.5-1.0 inches in the Jackson Hole Valley.
Rain will taper off early Saturday morning and we should see a nice break in the action through much of the day on Saturday with partly cloudy skies and highs in the 60s. However, winds will also become strong out of the southeast with gusts to 30-40 mph possible.
Attention then shifts to a strong low pressure system that will approach from the southwest and track across Western Wyoming on Sunday. Ahead of the system, some isolated shower/thunderstorm activity can’t be ruled out later Saturday afternoon, then more widespread showers will arrive sometime on Saturday night (still some uncertainty as to whether it arrives in the evening or later in the night).
Snow levels will fall to 7,500-8,000 feet on Saturday night, then a cold front will arrive during the day on Sunday (likely around mid-morning) with snow levels ranging from 6,500-7,500 feet behind the front during the daytime hours. We could even see some wet snowflakes mix in across the valley floor and in the town of Jackson at times on Sunday.
Significant rain and snow totals are likely to add from later Saturday night through early Sunday evening, before giving way to lighter and more intermittent showers on Sunday night. Temperatures will be very chilly on Sunday with highs only in the 40s in the valley, and highs may even occur early in the day with steady/falling temperatures in the afternoon.
Heavy snow is likely across the mid to higher elevations of Tetons on Sunday, with snow totals from late Saturday/early Sunday through Sunday night ranging from 6-12 inches above 8,000 feet and anywhere from a dusting to a few inches of wet/slushy snow between 7,000-8,000 feet.
Expect to encounter snow if you’re driving over Teton or Togwotee Passes on Sunday, and also in Yellowstone National Park.
Additional rain and snow showers will develop on the backside of this system throughout the day on Monday with snow levels rising to 8,000 feet on Monday afternoon. Higher elevation areas could pick up an additional few inches of snow on Monday.
Total precipitation amounts from Saturday night through Monday night will range from 1.5-2.5 inches in the Tetons and 0.75-1.5 inches in the Jackson Hole Valley.
On Tuesday, we will start to warm back up with a bit of a break expected early in the day. However, another disturbance approaching from the west will result in increasing chances for showers and thunderstorms again from Tuesday afternoon through Wednesday.
A second disturbance will keep the pattern of unsettled weather and daily chances of showers going through the end of next week. Memorial Day weekend is uncertain at this point, but there is a chance the unsettled pattern could stick around through at least the start of the weekend.
Alan Smith, Meteorologist
