JACKSON, Wyo. – High temperatures have topped 50 degrees in Jackson on each of the past three days. However, “false spring” will soon be coming to an end with frequent storms and colder temperatures expected over the next one to two weeks.
Recent Weather
The most recent storm on Thursday, March 6 produced 3-8 inches of snowfall in the Tetons and 1-4 inches in the valley, including 3.9 inches in the town of Jackson.
We have been in a dry pattern since this storm exited with chilly temperatures initially giving way to a significant warming trend with spring-like conditions.
The high temperature in Jackson has hit 51ºF on each of the past three days and snowpack in town is quickly melting away as a result.
Temperatures have also been quite mild in the Tetons leading to spring skiing conditions, though strong winds have limited how warm it actually feels.
So far this month, temperatures are running 2.9ºF above normal in the town of Jackson. However, we will be heading into a colder pattern soon which could balance this out by later in the month.
The view below of Teton Village and Jackson Hole Mountain Resort represents how things have looked this week, with sunshine and thin/high clouds on the ski slopes and a receding snowpack in the Lower Valley.
Snowpack remains healthy despite the recent warm and dry weather. Currently, snowpack is 102% of average in the Tetons after flat-lining recently. Snowpack may increase relative to average over the coming days and weeks with multiple storms in the forecast.
In the graph below, the black line shows the current snowpack (measured by snow water equivalent) in the Snake Headwaters Basin while the green line indicates the average values. The blue and red lines indicate 30-year maximums and minimum values for the period of 1981-2020.
Upcoming Weather Pattern
The pattern is about to flip across the Western U.S. with frequent storms making landfall and tracking across the Rockies over the next one to two weeks.
The first storm will arrive on Thursday and will bring snow to the Tetons and rain or a rain/snow mix to the valley initially.
However, a cold front will move through early on Thursday evening, resulting in a period of heavier snowfall rates along with a transition from rain to snow in the valley. The evening commute is likely to be impacted, especially over Teton Pass, while valley roads could be slick first thing on Friday morning.
A lull in the pattern is expected on Friday but temperatures will be much colder with highs only in the low 30s in the valley.
The next storm will be weaker and will produce more terrain-driven snow showers over the Tetons on Friday night and Saturday (moderate amounts possible, especially up high) with lighter and more intermittent activity over the valley.
Winds will be moderate out of the west and atmospheric forcing will be limited, which will lead to a Teton shadowing effect with limited moisture reaching the valley. Temperatures will remain chilly however with highs in the low to mid 30s. Average highs in mid-March are in the low 40s, for perspective.
A longer duration storm is likely from Sunday through Tuesday as a low pressure system moves from the Gulf of Alaska into the Western U.S. We could see a series of waves arriving with this system with the potential for significant snow totals to add up.
Temperatures will trend warmer on Sunday and into Monday before trending colder again by late Monday or early Tuesday as a cold front moves through.
The valley is likely to see some snowfall accumulations during this period in addition to the Tetons.
However, by this point in the season, valley accumulations are often limited to the nighttime and morning hours, with melting more typical in the midday and afternoon hours due to a higher sun angle and warmer average temperatures at this time of year.
Winds could also be strong at times during this pattern, especially on Sunday and Monday. This will lead to areas of blowing snow and limited visibility in exposed areas.
The map below shows projected snowfall over the next 7 days and represents the average of 50 simulations of the European weather model. In addition to the Tetons, this is an impressive snowfall projection for Western North America as a whole and will make skiers happy throughout the West.
During the middle of next week, we may see a brief lull in the weather pattern around Tuesday, March 18. However, an active pattern is likely to resume shortly thereafter with more storms possible later next week.
NOAA’s 8-14 day outlook for March 20-26 indicates an increased likelihood of above-average precipitation across our area, while we are right on the edge of being favored for near-average or below-average temperatures.
Alan Smith, Meteorologist
