Pattern change brings snow this weekend
Thursday, December 11, 2014
The current stretch of warm and dry weather looks to change by mid-weekend as a splitting storm currently pummeling California moves eastward. Another nice day on Friday will be followed by increasing cloudiness on Saturday as the storm enters the Great Basin. Precipitation for us may start as early as Saturday afternoon, or may hold off till later Saturday night or early Sunday morning.
The strongest part of the storm will pass to our south, but we should do well in the cool and moist northwest flow behind the main energy center of the storm during the day Sunday. Furthermore, models now have a portion of the northern part of the split storm hanging back over southern Idaho or southwestern Wyoming and enhancing snowfall again by late Sunday night or Monday morning.
Forecasting snow amounts is difficult due to the strongly evolving nature of this storm, but currently I would expect only light snowfall in the 1-4” range to be reported Sunday morning. Periods of moderate to sometimes heavy snowfall will likely occur during the day Sunday and overnight, leading to accumulations of 5-10” by Monday morning. And additional 1-4” will likely fall during the day Monday to be reported Tuesday morning.
After a break Tuesday, the progressive forecast from the American GFS model last week wins out over the forecast from the European ECMWF. Interestingly, this is the second time the this winter the GFS showed superior skill in the medium range, and is something to take note of moving forward.
The progressive forecast moves another splitting storm over our area by midweek. Again, there will be uncertainty with respect to snowfall amounts, but the storm will likely peak around later Wednesday before exiting the area on Thursday. And the storm train will continue with another similar wave timed for the following weekend.
Continued dry and warm until mid-weekend
Monday, December 8, 2014
The current warm and dry pattern will persist through this week. The weak storm for tomorrow mentioned in last week’s forecast will indeed remain to our north and will bring only high clouds to the area.
The next chance of any weather will be mid-weekend as a very strong and warm Pacific storm brings copious moisture to California. Clouds should increase over our area on Saturday, but the storm is forecast to split as it enters the Great Basin, as indicated in last week’s ensemble forecast.
When meteorologists look for clarity in the longer term, the ensemble forecast provides an indication of possible future states of the atmosphere. Basically, a model is initialized with slightly different initial conditions, which can be considered to be the result of small measurement errors. A number of model runs produce an ensemble forecast, and the hope is that the future state of the atmosphere will fall within the range of predicted solutions. Furthermore, the amount of spread between the solutions is representative of the uncertainty of the forecast.
So, even though the operational models last week indicated a big storm for this coming weekend, the ensemble members indicated a possible split in the storm that grew more likely as the week progressed. And, in fact, the operational models are now predicting a split storm that will produce only fair amounts of snow for our area.
There is some cool air associated with the storm, and winds should briefly turn to the northwest behind the front, but this does not look like a big snow producer. Current forecasts have precipitation starting later Saturday and peaking overnight, with snows tapering off during the day Sunday. If I had to guess today, I would expect 3-6” by Sunday afternoon.
There is considerable model disagreement after next weekend as the European ECMWF keeps energy off the west coast and builds a ridge over our area, while the American GFS moves this energy over our area by midweek.
Meager snowfall chances for the next week
Tuesday, December 2, 2014
Warm weather and weak storms will doom our snowfall potential through at least next week. The storm for tomorrow has weakened from earlier forecasts and while clouds will increase later today ahead of the wave and remain for tomorrow, I only expect an inch or two by Thursday noon, with rain possible in the valley during the day Wednesday.
Another disappointingly weak wave moves over the area on late Thursday night and Friday, with one model predicting no precipitation and another maybe an inch or two by the end of the day.
A quick-moving and shallow ridge for early Saturday will be followed by another weak storm which will increase clouds later Saturday into Sunday, but current forecasts have this weak storm splitting and weakening further as it enters the west coast, leaving our area precipitation free.
Yet another insignificant and likely precipitation-free wave is timed for around Tuesday, with a building ridge bringing even warmer and still dry weather to our area for later in the workweek.
Weak and warm storms for Sunday, midweek and next weekend
Saturday, November 29, 2014
After some partly sunny days, moisture should increase later tonight and tomorrow ahead of a weak storm that will peak Sunday night or early Monday morning. Areas north of Steamboat will be favored, but only an inch or two is expected to be reported on the hill by Monday morning.
Light snows will end by noon Monday and clouds will decrease through the afternoon, leaving partly cloudy skies for the rest of the day and Tuesday.
A storm currently off the coast of California will move inland and affect our weather for Wednesday and Thursday. Models have trended weaker and warmer with this storm, but it still looks like we will receive not insignificant amounts of snow starting Wednesday afternoon and extending into Thursday. The most favorable time for snow will occur Wednesday night and Thursday morning as there is a subtle wind shift to northwest flow around then, but amounts will be limited by warm temperatures and light wind speeds. Based on the latest model runs, we may see 3-6” between noon Wednesday and noon Thursday.
Several weak and continued warm waves are forecast to follow this storm and pass over the area from Friday through the weekend, keeping the threat of light precipitation present.
Opening day conditions were …interesting
Wednesday, November 26, 2014
The freezing rain event that started the afternoon before the Steamboat Ski area opened for the 2014-2015 ski season ruined about 30” of powder that had fallen in the previous 3 days. 
But plans were made, and our group dutifully showed up at the gondola line at 7:30am, hoping for anything better than the ice-crust left in the valley snowpack.
We headed to White Out, but probed the snow prior to committing, and found an even thicker layer of ice at the top of Norther. Skiers behind us noisily and spectacularly proved that off-piste was unskiable, and we took the cat track around to Rudi’s Run, which was nice for early season conditions, but disappointing for those with powder expectations.
Shown on the left is a closeup of a nice slab of crust excavated from the top of Hurricane. After obtaining photographic documentation, we found Heavenly Daze and especially Vogue as having the softest snow on the hill.
Sun should return tomorrow, and we’ll see what the grooming crews can do to mitigate the damaged snowpack.
