Cold valleys and warmer mountains persist through the weekend
Thursday, December 31, 2015
The valley temperature as of 1pm has warmed from a low of -23F to 6F while the summit of Mount Werner has warmed from a low of -7F to 13F under sunny skies. A dry grazing wave mostly north and east of us will drag some more cold air over the Steamboat Springs area later tonight, continuing the below -20F low temperatures for the valley into New Years Day and the day after. Meanwhile, a portion of the West Coast ridge bends over the area, noticeably increasing mountain temperatures by Saturday.
The mountains will warm further through the weekend and into the next work week before a Pacific storm makes landfall in Southern California early Monday, backing our winds to the southwest and likely mixing out the cold valley inversion either during the day Monday or Tuesday.
There may be some light showers by Tuesday afternoon as the weakened storm moves mostly south of our area, but it appears accumulations may be minimal. Another stronger storm follows closely behind, but current forecasts have this storm staying south of our area at the end of the work week as well.
Uncertainty increases by the weekend as the American GFS has another Pacific storm undercutting the West Coast ridge and perhaps phasing with some cold Canadian air while the European ECMWF keeps the weekend storm offshore and the cold Canadian air to our north.
Frigid temperatures in the valley but warmer on the hill
Sunday, December 27, 2015
While the valley is still stuck in just-below zero temperatures after a -20F start to the day, the upper mountain has warmed to 18F as warmer air aloft has moved into the Steamboat Springs area. Monday should be a repeat of today before a dry wave drags some more cold air over the area early on Tuesday, cooling mountain temperatures but ironically bringing some warming to the valley as the strong temperature inversion is moderated.
A series of weak storms from the northwest and north will interact and threaten the area with light snow and continued cold temperatures beginning later Tuesday or early Wednesday. Light fluffy snow will likely fall for all of Wednesday and into Thursday morning before clearing skies should be noted by later in the day Thursday. Depending on when the snow starts, there may be several inches of snow on the hill by Wednesday morning and 3-6” by Thursday morning.
A West Coast ridge typical of recent El Nino episodes forms near the end of the work week, though temperatures will remain cool as the midweek storms are absorbed underneath the building ridge. There is a fair bit of uncertainty for next weekend’s weather as Pacific energy may interact with not only the lingering storm underneath the ridge, but also a grazing Canadian wave containing very cold air.
Last storm in this series arrives for Christmas Day
Thursday, December 24, 2015
After last week’s three foot storm cycle, the 7” mid and 8” up top reported this morning, almost all of which fell during the day Wednesday, leaves the Steamboat Ski Area with another storm cycle total of 35” at mid and 42.5” up top since Sunday night.
After a dry day today, a large storm currently located over the central West Coast will begin to stretch tonight and eventually split by later tomorrow. Energy leading to this split will move over the Steamboat Springs area sometime after midnight tonight and before sunrise tomorrow, likely leading to light falling snow for Christmas morning.
Additionally, the energy moving over our area looks strong enough to form a secondary closed low that will veer our winds from the southwest to the northwest by later in the day, increasing the chances of moderate to sometimes heavy snowfall in the afternoon.
Lighter snows should continue overnight as this secondary low moves east of the area, and may linger Saturday morning. I would expect 6-12” to be reported Saturday morning, with a significant portion of that falling between noon and midnight Friday.
Very cold temperatures will be reinforced for Saturday before warming at higher elevations should be noted by Sunday as the skies clear. Valleys will stay chilly as a temperature inversion reforms after the storm passes.
Monday should stay sunny with pleasant mountain temperatures before a series of weak storms interact and threaten the area with light snow for Tuesday. These storms will drag some more cold air over the region that may be reinforced by another weak storm around Thursday.
Long term models indicate that a Gulf of Alaska or West Coast ridge typical of recent El Nino episodes is likely to form around next weekend, possibly diverting the recent stormy weather around the West and Inter-mountain West.
One to two feet or more likely by Wednesday afternoon
Monday, December 21, 2015
The Steamboat Ski area reported 5.5” this morning and 6” up top, and by 11am an additional 5.5” fell on mid-mountain and 3” up top. After a brief break this afternoon, the snow machine cranks up again tonight as a wet Pacific jet stream takes aim on Colorado. Relatively warm temperatures and very strong westerly winds are expected through midnight as snow starts up again around sunset or early evening tonight.
The winds should moderate sometime after midnight as some cool air moves over the area, but will likely stay strong through the early morning before relaxing and veering more to the northwest by noon Tuesday. Periods of moderate to heavy snow should occur tonight and through the day tomorrow. Including what fell today, I would expect 6-12” to be reported Tuesday morning with at least that much again for the Wednesday morning report.
Snowfall will likely continue at much lighter rates early Wednesday before the final wave in this train, this time in wet but not as windy northwest flow, moves over the area later Wednesday morning, There is some cooler air with the wave, so I would expect lighter density snow during the day before snowfall begins to taper off, but not end, after sunset. I would expect another 4-8” to be reported Thursday morning.
Light snow early Thursday should turn into even lighter flurries or even end for a bit later Thursday before a large and strong storm crosses the West Coast and backs our winds to the southwest on Thursday. The snow from this storm may begin early on Christmas Day as waves eject from the parent low to our southwest and move over the Steamboat Springs area. This storm is currently forecast to last all day, but I expect the forecast to evolve over the next few days as there is a lot going on with the preceding storm.
The snow machine cranks up again starting Sunday
Friday, December 18, 2015
Even after a week of snow, tomorrow may be our only snow-free day for a while as a quick moving wave passes over the Steamboat Springs area Sunday and veers our flow from the southwest to the west and northwest. Snow should start falling during Sunday morning and periods of light to moderate snow should continue overnight and through Monday as additional weak waves Sunday night and Monday pass over the area. The timing of these waves in generally moist west to northwest flow is difficult and differs between the models, but I would expect around 4-8” of snow by Monday morning.
After a brief break and 2-5” for the Tuesday morning report, the snow machine cranks up again starting early Tuesday as a wet Pacific jet stream takes aim on Colorado and brings snow and windy conditions, especially to the higher elevations. Periods of moderate to heavy snow are forecast during the day Tuesday and overnight, leaving around a foot or more of fresh for the Wednesday morning report.
Snowfall should taper off, but likely not end on Wednesday and Thursday before a major storm is forecast to cross the West Coast early on Christmas Day. There are indications of a split storm which adds additional uncertainty to the forecast, but snow may increase over the Steamboat Springs area as waves eject from the storm located to our southwest as early as Christmas afternoon. This storm may be a slow-mover, though forecast details are sure to change with so much happening between now and then.
