We’ll see one more warm day on Tuesday with highs reaching the low 70s in the valley. The stubborn high clouds are finally gone as well, so enjoy the sunshine while it lasts! On Tuesday afternoon, gusty winds will develop out of the south along with scattered cumulus clouds. There will be only a very slight chance of an afternoon shower or thunderstorm, but most of the activity will remain farther west in Idaho.
Big changes are on the way from Wednesday through Saturday as two storm systems arrive, bringing colder air and significant precipitation. A leading-edge cold front will arrive on Tuesday night, resulting in a chilly day on Wednesday with mostly cloudy skies. We could see a few rain showers by late Wednesday morning before more widespread rain arrives from Wednesday afternoon through Thursday morning.
The rain/snow line will start out around 7,500-8,500 ft. on Wednesday afternoon before falling to 6,000-7,000 ft. on Thursday morning, so we could see some snowflakes falling in Jackson on Thursday morning with an even better chance north of town in the GTNP valley.
If you’re driving over Teton Pass or Togwotee Pass, or north into Yellowstone, then expect to encounter snow and slushy roads on Thursday morning. Higher elevations above 8,000-9,000 ft. will pick up 4-8 inches of snow from Wednesday through midday Thursday.
After a break in the action on Thursday afternoon and evening, the next storm system will bring more precipitation from roughly Friday morning through midday Saturday and this storm has the potential to bring even heavier snow amounts to the mountains. The rain/snow line could drop to the valley floor again by Friday night/Saturday morning, with valley areas in GTNP possibly waking up to some slushy snow accumulations on Saturday morning.
Fortunately for holiday weekend warriors, conditions will improve on Sunday and Monday with warmer and drier conditions.
Alan Smith, Meteorologist