Thursday, December 12, 2013
Mountain slopes have warmed nicely while the valleys remain cold while trapped in strong temperature inversions. In fact, warming temperatures aloft counter-intuitively strengthen lower-level inversions as vertical mixing in the lower levels is suppressed in the stabilizing airmass. The cold air in the valley bottoms then stays cold as the surface warming is minimized by the shallow sun angle and reflective snow surface.
There are some weak disturbances influencing our area starting tomorrow, though there is very little chance of significant accumulations. A wave to our south crosses too far south Friday morning for any snow, while another wave from the northwest is forecast to split as it moves over us later Friday, perhaps producing some light snow showers. Yet a third wave is forecast for early Sunday morning and that may produce a bit of snow as well.
Waves graze our area in warm and dry northwest flow Tuesday and Wednesday, but only a slight moderation of temperatures are expected. The developing story is the likely return near the end of the work week of Big Blue, the meteorological euphemism for an arctic outbreak similar to what we observed last week.
Lots of details are still to be resolved by the numerical models, but agreement between the models is trending stronger with this major cold and likely snowy pattern change near the end of next week.
Wednesday, December 11, 2013
A beautiful sunny day and much warmer temperatures in the low teens made for a delightful afternoon of skiing. The cold temperatures have kept the snow in fine shape and contributed to soft powdery skiing in the less skied areas. I did 3 runs in the Shadows and Closet area before finishing up with a cruiser down High Noon to Rolex. Still a bit thin for the evergreens on that side of the hill, but the left side of Rolex had great snow with minimal bumps.
Lower down Rolex I did venture into the aspen, and there were still short lines of untracked, though I had to cross many tracks to get those three or four linked powder turns. After riding Elkhead, I headed over to Oops to ski more cold northwest facing snow. While that was good, I had high hopes for Concentration which looked very recently opened, perhaps as recently as today. However, this snow was very stiff and made skiing both the untracked powder and the tracked snow difficult.
Up one more time and a final cruiser down Heavenly Daze and SeeYa with great views of the South Valley. I did notice that Ted’s Ridge was also recently opened, but I was trying to catch a bus and opted for the beeline down the hill.
Tuesday, December 10, 2013
Very light snow is currently falling on the hill as a weak wave in northwest flow grazes our area today. Temperatures on the hill are running about 10F warmer than yesterday, and they will warm further, especially Wednesday and Thursday. Mountain valleys, however, will remain cold as temperature inversions maintained by the clearing skies expected tomorrow and Thursday allow for strong nighttime cooling of the snow surface.
Our next chance for snow occurs late Friday as another weak Pacific wave from the northwest is forecast to cross our area. Snowfall is expected to be light at this time, but the bigger effect may be that valley inversion are moderated as the storm passes.
Seasonal weather is expected to continue into the following week before another arctic surge may impact us near the end of the work week. This outbreak may be similar to the current one with sharply colder temperatures and moderate to heavy snows, though a 10 day forecast is likely to change as the event nears.
Sunday, December 8, 2013
A 4” mid-mountain report with 7” up top and snowing sounded promising on the 5am report, indeed by the 1pm report there were 9” at mid and 8” up top. The temperature at the Storm Peak Lab fell from 0F at the 5am report to -7F by 8:30am, so I prepared for another cold powder day.
While riding up the Gondola, I noticed Patrol had opened Upper Valley View for the first time this season, so took that as my first run. A bit tracked up top, but very deep bottomless turns near the sides. On the way back to the Gondola, I noticed that the Bashor chair was running for the first time this season, so I did a couple of laps in the untracked in Bashor Bowl. Again, deep powder, but the pitch was just not steep enough to make many linked turns.
Back up the Gondola and up Storm Peak to check out Shadows, and I was very surprised to measure 11-15” of snow in the favored locations. I’ve not been in Shadows for a couple of days as I was skiing the newly opened terrain around Rolex, so not sure how much of that fell overnight. But really good powder, especially the lower half of Upper Shadows down to the Duster cat track.
Most of the remaining part of the storm is currently moving through the area as temperatures up top have dropped from 0F at 5am to -7F at 8:30am as light snow continues. Temperatures will likely continue to fall or remain this cold until tomorrow morning when a trailing wave finally pushes the coldest part of the storm east of the area. Snow showers on the hill will likely continue until tomorrow afternoon, though additional accumulations after noon today will be minimal due to the very cold temperatures and drying airmass.
Another grazing wave in northwest flow will keep temperatures cold and start light snow showers on the hill again during Tuesday afternoon and evening. There should be some warming on the mountain slopes by Wednesday, but it will be most noticeable on Thursday as the trough that had been sitting over the western part of the US moves east. Mountain valleys, on the other hand, are likely to remain cold as strong inversions develop and persist.
Models currently forecast a weak storm for the following weekend. A flat ridge looks to build in the Gulf of Alaska which may shunt Pacific energy to our north and create mostly dry conditions after that.