Skiing & Riding At Alpine Meadows Just Got A Bit Cooler

So yes, skiing and riding at Alpine Meadows was a bit cooler today. Yesterday mid-mountain temperature were around 60° and today they only reached into the mid-50’s. After skiing in t-shirts yesterday, it was back to a light jacket today, also fending off some of those light rain showers. Those cooler temperatures did not really improve the skiing and riding, but it did allow me to write that totally clickbait headline.

The forecast for Alpine Meadows today called for a chance of showers in the morning, then a chance of thundershowers in the afternoon. But this is one of those cases where you can’t always predict exactly what is going to happen. What brought us those cooler temperatures was a strong marine flow, or Delta breeze, returning to California. Besides being cooler, that air also carried a lot of moisture in the form of heavy fog at the coast and higher humidity inland. That higher humidity is problematic for good snow conditions. So even though the temperatures were slightly colder, the snow conditions were quite a bit worse.

Giving some concrete numbers here, the relative humidity was 43% at 8am at the top of Summit yesterday. Today it was 96% at the same hour. Being a former teacher of science, here’s the lesson. Heat and temperature are not exactly the same. Over the last several nights, the air temperature has been higher than the snow temperature. But overall the snow still stays frozen because without the water, the warm air does not have as much heat. Heat depends on mass. But last night there was a lot of water in the air, and that adds a lot of mass to the atmosphere. So although the temperature is slightly colder, there is more heat within that air. That causes snow to melt faster, or at least feel wetter and stickier.

A reader that is smarter than me pointed out this is not correct at all, because humid air is actually less dense than dry air. That’s absolutely counterintuitive but the Wikipedia article linked in the comments does the math. It’s above my pay grade. Here’s a different explanation from Cliff Mass:

If air has a lot of water vapor and the dew point is high, water vapor in the air can condense on cold surfaces,  like snow.  And when water vapor condenses, it releases a large amount of energy:  the latent heat of condensation, which is around 600 calories per gram of water condensed.  As most of you know, calories are a unit of energy.  Such condensation is like putting a strong heater on the surface of the snow.

On the groomed slopes this morning, that translated into softer conditions that rutted up pretty quickly. Lower on the mountain, things were somewhat firmer. Off piste skiing was pretty disappointing today. everything I tried was slow, mushy and sticky.

Did we mention that in addition to the flat light, the grooming had a lot of “artifacts” today? Yes, curbs, ruts, death cookies and death pumpkins…they were all there for your skis to find today. It’s not the fault of the grooming team. In the spring, when temperatures rise to 60°, the snow turns to a slurpee. Some poor snowcat driver is tasked with driving a 20,000+ pound machine over that slurpee to try to smooth it out. It’s essentially an impossible task at warmer temperatures. If you like spring skiing, you learn to live with that, or you ski off piste when you can.

That Lightning Arrived Earlier Than Forecast

Then there was the earlier than expected lightning. A humid atmosphere plus a lot of sunlight are the ingredients needed for a rapid buildup of thunderstorms. That rapid buildup started just a bit southwest of Alpine Meadows, resulting in a lot of lightning strikes around 9:30 this morning out around French Meadows reservoir. At 9:37, all lifts at Alpine Meadows went on lightning hold except for Subway, Meadow and the Big Carpet. Sources indicate that a lightning alert gets issued when lightning is within 30 miles and a hold happens when lightning is 10 miles or less away. That hold generally lasts until it has been 60 minutes without lightning. These are pretty much standard for the entire outdoor industry, not just at Alpine Meadows.

I took a short break to grab a coffee and analyze the lightning app and weather radar on my phone. With things looking relatively safe for the lower lifts, I went back out and spun a few laps on Meadow, Subway and the Big Carpet. We even managed to ski a black diamond run, traversing over to the bottom of the Promised Land. Then we called it, took off the ski boots and put away the ski gear. As we started to walk out the breezeway, Rayna the mountain host alerted us that the lifts were now off of the lightning hold.

By 11 am, we had our ski boots back on and headed back out to the mountain. It was like a private resort during that hour, with zero lines, and completely open slopes. That said, there was some drizzle and rain drops. That additional dampness added to the snow surface just keep making it slower and slower, especially in the flat areas.

Sherwood did not run today, and hopefully that does not mean it is done for the season. I did not find anyone on the mountain today that had the answer to that question. Also saw some Mount Rose folk at Alpine Meadows today and yesterday. Mount Rose chose to not operate midweek for their final week. Yes, we have been there too.

Rain & Snow?

The model trend over the last 48 hours has been to slightly raise the amount of moisture in the upcoming storm. This is not ideal for skiing or riding on Friday, nor for farmers that are hoping that various blossoms will set for some crops. Here’s the latest run of the GEFS for total precipitation:

With about 0.75 inches of precipitation, one would expect about 8 inches of snow. But snow levels will start high, around 10,000 feet. They drop down to about 6-7000 feet as the storm ends on Friday. The point forecast for mid-mountain at Alpine Meadows now calls for 1-3 inches of snow. With higher humidity and then rain, it likely will remain fairly sticky this week.

Wednesday morning update: Humidity is running 88 to 100% on the mountain this morning but temperatures are very close to or below freezing. The high temperatures are only supposed to hit 50 degrees so this should be a good day.

As of right now, the weekend does look mostly sunny with good cold overnight lows. If we only get an inch of snow, the corn might recover quickly. If we get three inches or more we will be ending the Alpine Meadows season in a mank cycle, which is not ideal. It would be a reason to consider playing snow golf, which is scheduled for Saturday. Music is scheduled for both days this weekend on the Alpine Sun Deck, with no details announced. Shocking, I know. A little bird mentioned Boot Juice not long ago.

Today was not ideal, but we managed to milk a lot of fun out of the day anyway. There’s always tomorrow.