Update Saturday morning, June 8th: (scroll down to read post from Friday)
Forecast verifying pretty well, seeing snowflakes in the Town of Jackson this morning. Snow on the ground down to around the 6,500-ft. elevation.

Grand Targhee is showing over 10 inches of new snow overnight and early this Saturday morning. Screen shots from webcams below….

How unusual is snow in June? Not too unusual, but accumulating snow in Town (elevation 6,200-ft.) in June is rare. The record one day snowfall in June in Jackson was 4 inches on June 18th, 1973.

Post From Friday, June 7th:
A cold Low-pressure system will be moving across the Pacific Northwest & Northern Rockies Friday & Saturday, June 7th & 8th. This will bring some rain, a few thunderstorms, and a mix of rain and snow to the mountains of Northwest Wyoming. A cold front is currently stalled over central Idaho, but it will progress eastward the next 24-hours.

Snow in June

Yellowstone National Park will see more significant accumulations of snow late Friday night/early Saturday morning. As well as, the Beartooth Mountains of Southwest Montana. Lesser amounts in the Tetons, Wind Rivers, & Bighorns of Wyoming. Snow levels will be low enough to possibly create a mix of rain and snow in Jackson Hole.

Better Weather Sunday

Good news is, all this weather moves east of the Rockies later Saturday, with drier weather & warming temperatures Sunday into Monday. Click the Forecast Weather Map below to see where the worst weather will be the next few days, across the USA.

Post by meteorologist Jim Woodmencey

Weather is changing across the Western U.S. for the weekend…..Warm air in place ahead of a cold Low-pressure center positioned off the Pacific Northwest coast this morning. Isolated areas of early morning Thunderstorms started popping up at sunrise. An indication that the atmosphere is already quite unstable.

Satellite & Radar Images, plus lightning strike map from @ 0700 MDT Thursday, June 6th, 2019 below. (Today is the 75th Anniversary of D-Day, by the way).

Below is Thursday’s Forecast Weather Map across the USA. Click the map to view the general weather outlook for next 3-days…..

Further updates on this weekend’s weather situation coming on Friday morning….

Post by meteorologist Jim Woodmencey

In General:

The weather across the western U.S. this Memorial Day Weekend won’t be all bad, but it would be hard to call it “good”.

One large, cold  trough of Low-pressure will move east of the Rockies Friday. Thursday’s jet stream map below, showing how far south the Low & the jet have been this week.

Now, click on the map above to see the jet stream pattern through Sunday night, May 26th. Once the current Low exits, another Low-pressure moves inland over the Pacific Northwest, which will take another dive towards the Southwestern U.S. The weather pattern the next few days  reminds me of a softball pitcher winding up……

That keeps the temps seasonably cooler through Memorial Day over the West, along with showers, thunderstorms and some mountain snow in the picture.

Yes I said, “Snow”!

More cold and more snow for late May 2019. Click Map below for a loop of where, when and how much snow the Western mountains are forecast to get.

Map below shows total accumulation through Sunday afternoon.

In Western Wyoming:

Moisture will again be pulsing across western Wyoming this weekend. Expect showers, heaviest rain looks to be coming on Friday. Maybe another dousing Saturday afternoon. Scattered showers for Sunday & Monday, a little less wet?

Check the forecast for Jackson Hole & the Tetons for more detailed & updated info.

Click on map below for the forecast precipitation, for each 3-hour increment, from Thursday afternoon to Monday afternoon, for the Northwest portion of the U.S.
Find your breaks to get outside!

Post by meteorologist Jim Woodmencey

Snow is not all that unusual in the mountains of the Western United States in late May. However, snow to low elevations is a more rare occurrence.

A series of cold Low-pressure systems have been marching across the West since this past weekend. These Lows have brought unusually cold air inland, producing measurable snowfall in the Town of Jackson, Wyoming and to many areas of Colorado.

Jackson, WY

Jackson’s official climate station reported one inch of snow on Monday morning May 20th, 2019. That is the first time in Jackson’s history that measurable snowfall has been recorded on that date.

That’s not to say it hasn’t happened, as missing observations, or snow that melts before it gets measured and recorded are quite possible.

Other dates with measurable snowfall in late May in Jackson include:
1 inch on May 22nd, 1966 (53 years ago).
2 inches on May 30th, 1978 (4 years ago).
3 inches, on May 21st, 1931 (88 years ago).

Denver, CO

On May 21st, 2019 Denver experienced its biggest snow in 44 years, with 3.4 inches recorded in a 24-hour period. That is the most  snow in one day in late May, since May 29th, 1975 when Denver recorded 5.6 inches of snow.

Denver also tied a record cold low temperature on May 21st, 2019 with a reading of 31 degrees F.

Even more impressive is that the high temperature only made it to 39 degrees F. That is the coldest May 21st in 128 years! The old record cold high temperature for May 21st was 40 degrees, set way back in in 1891.

Post by meteorologist Jim Woodmencey

Large Low-pressure system on West Coast will continue to cycle clouds and precipitation in and over the Western U.S. and Rockies through the weekend. Rain at lower elevations & snow in the mountains, generally above the 6000-7000-ft. elevations.

Current Situation

Below are this morning’s Satellite & Radar Images: Friday May 17, 2019

Weekend Forecast

Below is an animation of the clouds (represented by gray & white colors) and precipitation (blue-green colors), along with surface pressure contours (white lines in millibars). Video courtesy of Windy.com

Click on image below to view forecast maps from: Friday noon to Sunday evening.

Big Low-pressure rotates moisture inland in pulses, with plenty of clouds & showers each day, Friday through Sunday. Expect periods of heavier rainfall, and just a few breaks in the clouds & showers.

Also, much cold air is coming inland, cold enough in Jackson Hole for the possibility of some snow to the valley floor.

Another Low-pressure center in the Gulf of Alaska will be moving inland later Sunday and affecting the weather across the Western U.S. for most of next week, keeping it wet & cool.

Post by meteorologist Jim Woodmencey

As I have done for many years now in my column for the Jackson Hole News & Guide, I’ll review the winter season’s snowfall and see how it compared to past years.

In case you missed it, this February had record-breaking snowfall, both in the valley and the mountains. That month alone is what truly made this winter extraordinary.

As you can decipher from the tables below, each winter’s snowfall distribution is a little different. What stands out is, that two out of the last three winters were exceptionally powder-ful, with well above average snowfall in both the mountains and the valley.

Town of Jackson Snowfall Stats

Snow measured at the Jackson Climate Station totaled 86 inches between December 1st, 2018 and April 1st, 2019.

That is the official count, however, there were roughly three weeks, from January 9th to 29th, 2019, when snowfall measurements were not taken, due to the government shutdown. Therefore, the actual four-month snowfall total for town was probably between 90 and 100 inches.

The long-term historic average snowfall for Jackson, from December through March, is 61 inches. Which means that this winter’s snowfall was at least 40-percent more than the average.

Note that more than half of this winter’s snowfall came in the month of February. The 55 inches we received during February 2019 established a new record for February snowfall. It also placed February 2019 as the second snowiest month ever, in Jackson’s recorded weather history.

Two winters ago, in 2016-17, Jackson also had big snowfall. Town received 94 inches of snow in the December through March time-frame. But, that winter was much warmer. This winter was much, much colder.

It Was a COLD Winter Too

This winter we experienced average high temperatures that were significantly colder than the long-term historic average, for every single month, from December through March.

What really blew me away was that average low temperatures were also well below normal, every single month. That usually only happens during dry winter months.

The biggest departure in temperature happened in March, with an average high temperature of 33-degrees for March 2019. That is 7 degrees colder than the long-term average high temperature in March, of 40-degrees.

The average low temperature this March was 5.6-degrees, which is nearly 10 degrees colder than the long-term average low temperature for March in Jackson, of 15 degrees. That is a significant cool down.

February’s Record Mountain Snowfall

Analyzing the data from the Rendezvous Bowl weather station at the 9,580-ft. elevation of the Jackson Hole Mountain Resort, I found the total snowfall from December 1st, 2018 to April 1st, 2019 was 406 inches.

Almost half of that total amount fell in February this year, establishing a new February snowfall record on the mountain with 196 inches.

The average total snowfall at Rendezvous Bowl, for December through March, is 304 inches. That additional 100 inches puts this winter’s “ski season” snow total at 133-percent of average.

For the same time period during the big winter we had two years ago, in 2016-17, 462 inches of snowfall was recorded at Rendezvous Bowl. February 2017 accounted for 149 of those inches, which is now the old February snowfall record, after this February blew that one away.

End of Season Snow-depth

Another way to gauge the winter season is by looking at the settled snow-depth in the mountains on April 1st.

At the Rendezvous Bowl site, the settled snow-depth was 105 inches on April 1st, 2019. The long-term historic average snow-depth on April 1st is 103 inches. Which means snow-depths at the end of winter, at that elevation, were very close to normal.

In comparison, and this might surprise you, last year on April 1st the snow depth at Rendezvous Bowl was 131 inches, assisted by the 99 inches of snow that fell in March 2018. Two seasons ago, on April 1, 2017, the snow depth stood at 146 inches.

While snow-depths and snowfall in the valley were reaching record levels this winter, snow pack in the mountains ended up much closer to normal than you would think.

Posted by meteorologist Jim Woodmencey