It's been quite a week for the Jackson Hole region with record snowfall late last week followed by some of the coldest air in years early this week. In case you missed it yesterday, here is my storm recap post highlighting the 2-day snowfall record that was broken at Jackson Hole's Rendezvous Bowl Plot.

Cold Temperatures:

For the second morning in a row, we are waking up to frigid temperatures throughout the area with lows in the -20s to -30s in the valleys and -40s in Yellowstone. Above the valley floor (including all local ski resorts and Teton Pass), low temperatures are in the -10s for the second morning in a row.

On Monday afternoon, many areas did not get above zero, including the Town of Jackson where the high was only -6ºF. The JH Airport, Teton Valley, and most ski resort weather stations above the valley floor did manage to just barely get above zero, though Teton Pass did not get above zero.

The Town of Jackson weather station recorded a low of -30.5ºF (so -30 or -31 depending on rounding), which is the coldest reading since January 2017, and only the second winter season we have seen a low of -30ºF or colder since 2000.

Interestingly enough, the low occurred just after midnight before some mid to high-level cloud cover rolled in with temps actually rising a few degrees overnight. The cloud cover prevented any further radiational cooling, and had the clouds not rolled in, it would have gotten even colder. 

Temperatures of -30ºF have become rare in Jackson in recent years. This is only the second winter season since 2000 that we have had a low of -30ºF. It used to not be that uncommon. From 1970-1999, Jackson hit -30ºF in 16 of those years, or approximately one out of every two winters. 

The Jackson Lake weather station (near Moran Jct) has recorded lows of -32ºF and -31ºF the last two mornings – the first minus 30-degree readings at this location in 12 years since dipping to -37ºF in February 2011.

For historical perspective, the Jackson Lake weather station had at least one -30ºF day in 8 out of 12 years from 2000 to 2011, and in 20 out of 30 years from 1970 to 1999. 

In other words, extreme cold snaps involving -30ºF temps or lower in the JH Valley have become increasingly rare in recent years. 

Driggs dipped to -32ºF on Monday morning and -29ºF on Tuesday morning. Consistent and reliable past weather data is lacking at this location, though, so I can't offer any historical perspective here.

Here is a regional look at the low temperatures across the region on Tuesday morning:

Forecast for Tuesday to Tuesday Night:

A wave of mid-level moisture has moved into the Tetons, resulting in mid-level clouds that are mostly hovering above ski resort summit elevations, though pockets of lower clouds and reduced visibility will be possible from time to time.

As if Monday wasn't cold enough, the lack of sun on Tuesday will make it feel even colder, though actual air temperatures should warm up slightly on Tuesday afternoon compared to Monday with highs in the upper single digits (above zero) at 9,000 feet and low single digits (above zero) in the valley.

Winds will also be west/northwest at 10-15 mph with gusts to 20-25 mph at 9,000 feet, so it will be a very cold day for skiing when factoring in the brisk winds and lack of sunshine. We may see some partial clearing in the cloud cover on Tuesday afternoon, but I'm not expecting it to fully go bluebird at any point.

On Tuesday night, a weak disturbance will slide in from the northwest and we may see a few light snow showers or flurries overnight. Any accumulations will be minimal, however, no more than an inch or so.

Forecast for Wednesday to Thursday:

Dry conditions, comparatively milder temperatures, and a strengthening temperature inversion can be expected during this period.

On Wednesday, we will see partly cloudy skies but warmer air aloft will result in high temperatures rising into the low 20s at 9,000 feet. This will feel much more tolerable on the slopes compared to the past two days! Winds will remain moderately breezy out of the west/northwest on the upper mountain, however.

Valley temperatures on Wednesday morning will also start out milder thanks to Tuesday night's disturbance. We will likely start out near or just below zero in the valley on Wednesday morning before rising into the upper teens on Wednesday afternoon – still cold, but not nearly as cold as prior days.

On Thursday, skies will become mostly sunny with highs in the mid 20s at 9,000 feet. It will be a beautiful day to hit the slopes and escape the valley inversion. Winds will remain moderately breezy out of the west/northwest above 9,000 feet.

Valley temperatures on Thursday will likely start out well below zero in the morning (but not as cold as Mon/Tue) before rising into the teens on Thursday afternoon as the inversion remains in place.

Outlook for Friday (Feb 3) to Saturday (Feb 4):

A weak storm will arrive from the west during this period with light snow expected. The window of snow chances will be from Friday afternoon through Saturday morning, but I expected most of the accumulations to occur during the overnight period on Friday night.

Since we're within 5 days, I'll go with an early snow forecast of 2-4 inches in the Tetons and about a half-inch to an inch in the valleys. Snow quality should be "medium density" but trending from higher density toward lower density through the event as colder air aloft arrives.

While the mountains will see a slight cooling trend during this period, the inversion will finally erode in the valley, resulting in much milder temperatures with highs reaching the low 30s on Friday and Saturday afternoons.

Outlook for Sunday (Feb 5) to Monday (Feb 6):

A stronger storm is possible during this period with the potential for decent snow accumulations, especially on Sunday night and heading into Monday morning. However, my optimism is "cautious" at this time.

The storm will likely split apart at some point on its journey across the Rockies. If the split occurs late enough as most models are projecting right now, then we could end up with a nice snow event and potentially even a powder day on Monday. However, if the split occurs too early, then we could end up with very little snowfall. Time will tell as we get closer.

 

Outlook for February 7th-14th:

Following the February 5th-6th storm, I'm seeing some hints of a backside weak storm arriving from the northwest on Tuesday (Feb 7th).

After that, a storm is projected to move across the Northern Rockies around Feb 8th-9th, but it may end up too far north. Too early to stay for now, but it's worth keeping an eye on.

As we head into mid-February, the pattern doesn't look great but it also doesn't look terrible. The good news is that it's unlikely we'll see any extended periods of high pressure across the Western U.S.

However, the bad news is that it looks like storms will have a tendency to split apart and weaken as they reach the West Coast, which could mean that most of the moisture and energy reaching the Western U.S. (which may not be that impressive to begin with) will pass north and south of our area. 

This pattern is not a great look in terms of significant snow potential. However, we could still see some glancing blows in this pattern, and our hope to hold onto would be that this happens on a frequent basis with consistent rounds of light to moderate snow. 

That being said, models have been struggling beyond about a week out recently (even more so than usual), so I wouldn't write off the 1-2 week outlook just yet. 

Thanks so much for reading! Next update on Wednesday (Feb 1).

ALAN SMITH