Forecast for Tuesday:

It's a beautiful start to the morning on Tuesday with crystal clear skies across Jackson Hole and a large portion of Wyoming and Eastern Idaho.

Strong daytime heating along with steeper lapse rates (the rate of temperature decrease with altitude) will result in a better chance of thunderstorms this afternoon.

I wouldn't rule out a storm as early as noon, but the best chance will be from 1pm to 8pm with multiple rounds of storms possible across the higher elevations. Individual storms will likely be short-lived due to weak wind shear, but new storms could quickly form as old ones die out. 

Weak winds aloft will result in slow-moving thunderstorms that will move in a general SSW to NNE direction. This may largely keep thunderstorm activity anchored to the higher terrain, including the Tetons and surrounding ranges as well as the Yellowstone plateau. Thunderstorm coverage will be scattered in nature across the higher elevations and more isolated in the valleys. 

Cloud bases will range from 11,000-12,500 feet which is a little higher than recent days (indicating drier air in the low levels) with brief moderate rain possible with storms, but overall significant rain is not expected. Snow levels will also be a bit higher under this warmer airmass, ranging from 12,000-13,000 feet.

Also, I wouldn't rule out a few showers or even a thunderstorm during the overnight hours on Tuesday night. Something to keep in mind if you plan to be out camping. 

Forecast for Wednesday:

This is shaping up to be a more active day as a large area of low pressure moves northward from Southern California into Nevada.

As a result of this feature, moisture, instability, and wind shear are all going to increase, resulting in a threat of stronger and more organized thunderstorms. Storms will also move in a SE to NW direction.

Storms could develop as early as 11am on Tuesday with the best chance of storms existing from noon and beyond. 

Wednesday's thunderstorms will be capable of producing frequent lightning, moderate-sized hail (0.5" in diameter or more), and heavy rain.

Mulitple rounds of showers and thunderstorms are also expected through the afternoon and evening hours with a chance of showers persisting through the overnight period.

Outlook for Thursday (June 8) to Monday (June 12):

Thursday is uncertain as we will have a lot of moisture in place, but heavy overcast cloud cover is also possible which could end up suppressing thunderstorm coverage with just occasional light showers and cooler temps – similar to what we saw at the end of last week. If we do get any sun, though, then thunderstorms and heavy rain will be possible. 

On Friday and Saturday, the previous low pressure system will start to meander north/northwest away from our area, but lingering moisture and increased sunshine/daytime heating should in a good chance of afternoon thunderstorms both days.

The next area of low pressure will move into California and the Great Basin region on Sunday and Monday with another uptick in shower and thunderstorm activity possible. 

Thanks so much for reading! Next update on Wednesday (June 7).

Alan Smith