Warm snow today followed by cold snow on Monday
Sunday, February 23, 2020
The Steamboat Springs area is currently seeing some dense and very light intensity snowfall this Sunday noon with the temperature in town right at freezing and the temperature at the top of Mt. Werner 21 F. The storm from the southwest bringing the snow is departing, moved along by a much colder storm from the Pacific Northwest that will bring modest snowfall and unseasonably cold temperatures for Monday and Tuesday. There are good chances for more snow Wednesday night into Thursday even as temperatures rise before the weather dries and warms further heading into next weekend.
The Steamboat Ski area received an inch of snow early this morning from the warm storm that moved over the Desert Southwest yesterday. We could see another inch or two today as the storm departs that would be reported on the Monday morning ski report.
Following closely is a much colder storm currently crossing the Pacific Northwest coast. A cold front will pass through our area early Monday morning, likely around report time, bringing a quick inch or so of snowfall. Winds will swing around to be from the northwest and low-density snows will increase in the cold and unstable air mass through the afternoon, leaving 2-5” of accumulations by sunset.
Snows will continue overnight and through early Tuesday evening as they taper off during the day. With the expected 2-5” of snow overnight Monday, there could be as much as 4-10” of snow for the Tuesday morning report, with another 1-4” falling during the day. Temperatures will be quite cold, with high temperatures at the top of the hill struggling to reach the middle single digits on Tuesday before falling to below zero for Wednesday morning. And temperatures in town will be colder still for the Wednesday morning low if skies clear.
Meanwhile, a ridge of high pressure is forecast to build over the Gulf of Alaska on Monday and cross the West Coast on Tuesday. So we may see some sun after the cold start to Wednesday morning with warming occurring later in the day, especially at the higher elevations, as the ridge of high pressure approaches. However, Pacific energy and moisture riding over the top of the ridge will graze our area from Wednesday night through Thursday, bringing another chance of modest accumulations to the mountains.
At one point, it looked like another chance of snow for Thursday night, though latest weather forecast models have trended stronger with the ridge. With very cold air forecast to cover the eastern two thirds of the continent, there is still a chance that Pacific energy will mix with that cold air and move closer to our area, and with that in mind I’ll likely be moving my usual Thursday afternoon weather narrative to Wednesday afternoon in order to provide more details on snow amounts for Thursday and the possibility of a trailing storm for Thursday night.
In any case, the ridge of high pressure prevails for Friday and Saturday bringing a beautiful, warm and spring-like start to the weekend. However, there are additional Pacific storms lined up that could bring precipitation back to our area as soon as Sunday and continuing into the next week.
Snow chances for Sunday through Tuesday
Thursday, February 20, 2020
Thursday morning dawned clear and very cold in Steamboat Springs, with a low of -19 F at the Bob Adams airport and -7 F at the top of Mt. Werner. Under sunny skies, temperatures will moderate over the next few days, first at the higher elevations where the noontime temperature is already up to 15 F, and more slowly in town where the noontime temperature is only 2 F. There are chances for snow starting Sunday as first a warm system moves near our area and then a much colder system follows for Monday and Tuesday.
The current cold temperatures are courtesy of a piece of the last storm left behind that still contains very cold arctic air. Even though a ridge of high pressure is moving over our area today and tomorrow, bringing the sunny skies, the cold air is hanging around as it is trapped under the ridge. Clear skies, light winds and fresh snow cover allow nighttime temperatures to plummet, creating a strong temperature inversion where the lower elevations are cooler than the higher elevations as the dense cold air pools in the valleys.
While solar heating grows stronger each day as the sun moves higher in the sky, it is not yet strong enough to overcome the cold morning temperatures, so look for warming first at the higher elevations.
Meanwhile, a Pacific storm approaching the West Coast has split, with the northern part of the split weakening as it is deflected to the north by the ridge of high pressure over the West. However, the southern part of the split will form an eddy off the southern California coast that will mix with some subtropical moisture from the south as it crosses the coast on Saturday. Precipitation will move through the Desert Southwest on Saturday as the warm and wet storm moves to Colorado on Sunday.
Weather forecast models have trended further north with the storm, and while the southern Colorado mountains will be favored, our area will see clouds increase later Saturday with snow chances starting Saturday night. Currently, this is looking like a modest storm with high-density snowfall, with 1-4” expected by Sunday morning in the southerly flow ahead of the storm and 2-5” possible during the day as winds swing to be from the northwest and temperatures cool on the backside of the storm.
While these eddies can sometimes linger in one place, this one will be kept moving by a colder Pacific storm that is forecast to cross the Pacific Northwest coast on Sunday. And it will grow even colder as it moves across the Great Basin and mixes with cold air from the Canadian Plains . Low intensity precipitation will likely continue Sunday night into Monday morning between the storms and ahead of the cold front expected during the first half of Monday.
Snows will become lighter and fluffier along and behind the front and briefly increase in intensity Monday afternoon. Continued lighter snowfall in the favorable moist, cool and unstable northwest flow is expected through Tuesday as snows taper off during the day. There is disagreement between the weather forecast models on the amount of precipitation, but moderate totals are certainly possible. I hope to have more certainty in my next weather narrative, which, depending on the storms, may be Saturday or Sunday afternoon.
Weather forecast models agree we dry out on Wednesday as a ridge of high pressure builds over the West, with likely cold morning temperatures in the Yampa Valley as a temperature inversion is likely if skies clear. Another weak storm grazes our area later Wednesday into Thursday as it moves over the ridge of high pressure, though experience indicates the impacts may be stronger or weaker than currently advertised depending upon the strength of the storm and the ridge.
In any case, weather forecast models agree that the ridge of high pressure moves over our area for the end of that work week and heading into the following weekend, bringing March in like a lamb with the weather leaning more towards springtime rather than mid-winter.
Winter weather returns tonight
Saturday, February 15, 2020
Partly sunny skies are over the Steamboat Springs area early this Saturday afternoon ahead of another winter storm with copious moisture, similar to last Friday, that will start snows tonight. Persistent moderate to heavy snow and wind are expected during the day Sunday and overnight, creating difficult or impossible travel conditions. Though snowfall rates will diminish Monday morning, accumulating showers are expected again for the afternoon and overnight into Tuesday morning, along with sharply colder temperatures. Drier weather is advertised after the storm followed by warming after midweek, first noted at the higher elevations as the lower elevations will start the mornings cold due to temperature inversions forming. A warm storm is currently advertised around next weekend, quickly followed by a large, strong and cold storm for the beginning of the following work week.
An atmospheric river, or relatively narrow stream of moisture embedded in the jet stream, is currently impinging on the Pacific Northwest, and its mild origins from the central Pacific means our storm will start warm tonight. I would expect 2-5” by the Sunday morning report, with temperatures and westerly winds increasing during the day as the storm splits over the Great Basin. Snowfall rates around an inch per hour are expected through the day, at which point a cool front moves through Sunday evening and produces snowfall rates of lighter and fluffier snow as high as two inches per hour at times. I would expect 10-20” of snow to reported Monday morning at mid-mountain.
Though the atmosphere dries Monday, some of the split storm is forecast to move over our area Monday afternoon bringing much colder temperatures, even as some of the storm is left behind. The complicated evolution of the storm makes for an uncertain forecast from later Monday through Tuesday, especially since the cold temperatures that will be below zero at the top of Mt. Werner by Tuesday morning will inflate the snowfall totals. We could range from 1-4” at mid-mountain on Tuesday morning if the faster weather forecast models verify or 4-8” if the slower and more westward solutions are appropriate.
While Tuesday may feature some light snow showers, or not, cold temperatures will persist into Wednesday even as dry air tries to work into our area. But it is not clear how sunny we may be as we may still be under the influence of the now weak western portion of the storm if that solution verifies.
By Thursday, we will likely see warming, especially at the higher elevations, as a some sort of ridge of high pressure moves over the West ahead of another Pacific storm. This storm is forecast to split just before making landfall on Thursday, and while the northern part of the split is deflected to our north, leaving both Friday and Saturday warm and dry, the southern part of the split may mix with some subtropical moisture and bring a warm and wet storm first over the Desert Southwest and then our area by later in the weekend.
This warm storm is forecast to be kept moving by a large, powerful and cold storm that may move over our area in the beginning of the following work week. I will have more details on these storms in my next regularly scheduled weather narrative Thursday afternoon.
Change to the Morning Ski Report
Friday, February 14, 2020
I’ve changed the methodology used to produce the morning ski reports as of yesterday, 13 Feb 2020. As you may or may not know, SnowAlarm collates ski reports from around the continent from various sources, including the ski areas themselves, and you can sign up for free to have these emailed or texted to you.
Some of these sources allow the ski areas to report through the day, so my previous methodology of choosing the first available morning report could produce incomplete data depending upon the source. This made it difficult to tally the 24 hour snowfall totals over multi-day storms.
The morning report is now based upon the latest available ski report before 10 am local time. This now allows for the easy retrieval of 24 hour snowfall totals from previous days.
Next big storm starts on Sunday
Thursday, February 13, 2020
It was snowing this Thursday morning in Steamboat Springs, and with the 7” of snow currently showing on the Powdercam at the top of Sunshine Peak added to the 5” yesterday, the upper mountain has received around a foot of very light and fluffy snow. The phone report this morning disappointingly omitted the base measurements today, which is odd as I expect that we hit the century mark up top for the first time this season.
As discussed in the the last weather narrative on Sunday, this storm ended up tracking much further west than the weather forecast models had earlier indicated, which is not unusual when there is a giant pool of cold air to our northeast that is accessible to mix with storms from the northwest.
There may be additional showers this afternoon in the cold, moist and unstable northwest flow behind the storm, with another 1-4” possible before we dry out on Friday and see the sun return.
Another storm grazes our area on Friday night into Saturday morning, though this one is currently trending weaker than earlier forecast. While there is some cold air associated with the storm, and we may see some showers as the storm passes by through early Saturday, we may see some sun again by the afternoon as the inconsequential storm moves to our east.
But the break in the weather will be short-lived as a good-looking storm begins snow in our area on Sunday. While weather forecast models agree on significant precipitation, the disagree on the timing and length of the storm, with the European ECMWF currently bringing the greatest impacts during the day Sunday and the American GFS starting higher intensity snows later in the day Sunday and continuing them into the Washington’s Birthday holiday.
Most of the uncertainty is due to the storm possibly splitting as it crosses the Pacific Northwest coast on Sunday. The ECMWF keeps the storm mostly moving which means earlier snows with less duration. The GFS, on the other hand, forecasts a significant split in the storm, slowing its eastward movement and stalling the cold front over our area from Sunday night through part of Monday.
Either solution or a compromise is possible at this point, with a rough guess of a foot if the ECMWF verifies and possibly twice that if the GFS is right. I may push my regularly scheduled Sunday weather narrative to Saturday if there is more agreement in the weather forecast models by then.
Regardless, they both concur more cold air will follow the storm and persist through at least midweek. But the weather beyond midweek is very uncertain, and is dependent upon how much the storm ends up splitting earlier in the week. The more aggressive GFS, with its stronger split, has the southern end of the split forming a warm storm that moves over our area later in the work week, while the ECMWF has cooler and more showery weather for that time frame. Stay tuned for my next forecast on Saturday or Sunday for more details.