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.
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.
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.
Saturday, February 8, 2020
Sunny skies and warm temperatures are gracing the Steamboat Springs area early this Saturday afternoon as the town digs out of the impressive departing storm. The two day total ending at 5 am Saturday morning at mid-mountain at the Steamboat Ski Area was 22.5”, with almost of that falling between Wednesday and Friday nights. Tuesday and Friday currently look like the driest days of the upcoming week with cool temperatures and chances for some snow each of the remaining days.
I am pushing this weather narrative out a day early because I wanted to talk about the previous storm and note that there will be a cold front moving through our area during the Winter Carnival festivities at Howelesen Hill tonight, where there may be a world record firework attempt.
The storm delivered as advertised, though snow quality suffered due to a dense layer of snow that fell between 5 pm and 9 pm on Thursday evening. The 8.5” I measured on my deck at 5 pm was light and fluffy, and I observed some graupel falling around then, which looked like the round “Dipping Dots” frozen treat. By 9 pm, the additional 4” on my deck was much denser than what fell before it, and I believe this layer of snow fell over the whole mountain. Distressingly, there was also a layer of ice on the grab rails at the loading areas of the Sundown and Elkhead lifts first thing Friday morning which indicated an earlier period of freezing precipitation that likely fell on top of the dense layer of snow. While it was snowing heavily that morning, with snowfall rates approaching 3” per hour at times, the denser layer in between the Thursday daytime snowfall and Friday morning snowfall made for some inconsistent skiing.
But the sun is out now in advance of a cold front expected to pass through our area this evening, courtesy of the northern part of a splitting storm currently affecting the Pacific Northwest. Even the short-range weather forecast models are struggling with the forecast snow amounts, with snows, if they occur, starting after sunset and peaking around mid-evening before ending within a few hours after midnight. But the latest models have backed off snow amounts for our area in favor of areas to our south, making for an uncertain forecast. It’s likely we will see some snow around and behind the front, with briefly high snowfall rates of an inch per hour or more at times this evening, and at this point I would guess 2-5” which would be reported Sunday morning.
The cold front looks to stall south of our area as the main part of the split storm moves southward along the California Coast on Sunday. But energy ejecting out of the California part of the storm will overrun the front and keep the possibility of light snows for our area for Sunday and Monday.
Meanwhile, a wave of Pacific energy rounds the persistent ridge of high pressure in the eastern Pacific on Sunday. Not only with this bring another cold front through our area around Monday night, but it will also force the California storm eastward, with the two storms merging near the Four Corners on Tuesday. Most of the precipitation will be to our south, but light snow for our area will be possible for early Tuesday morning, along with cool temperatures, before the weather clears for most of the day Tuesday and some of Wednesday.
But hard to predict waves of Pacific energy are forecast to round the still-present ridge of high pressure in the eastern Pacific and graze our area later Wednesday and Thursday. These waves may end up too far east to give us much weather, or move further west giving us much better chances for snow, and at this time the outcome is uncertain.
It does appear that there will be a break in the unsettled weather for at least part of Friday before another storm may approach our area for the beginning of next weekend. I should have more details on the weekend storm by my next regularly scheduled weather narrative on Thursday afternoon, though I may push that to Wednesday if weather models trend stronger with the possible storms.
Wednesday, February 5, 2020
The Steamboat Springs area saw a cold start to this Wednesday morning, with a low temperature of -9 F at 7:35 am at the Bob Adams airport and -14 F at 1:50 am at the top of Mt. Werner. A Pacific jet stream will bring warming temperatures, wind and copious snow on Thursday and Friday before we see a short break on Saturday. A couple more storms bring chances for much less intense snow almost each day for the upcoming week, with midday Monday through midday Tuesday currently looking the driest.
I have to say it is tough to contain my excitement over the forecast snow amounts for Thursday and Friday. What meteorologists refer to as an atmospheric river, or well-defined stream of moisture, will round the top of a ridge of high pressure in the eastern Pacific and bring periods of moderate to heavy snowfall for the better part of two days, along with difficult to even impossible travel. Being of northern Pacific origin, temperatures are forecast to rise through today and tomorrow as the current arctic air mass is displaced, reaching around 15 F by sunset on Thursday as snowfall rates increase and approach an inch per hour.
Snowfall should start this evening, with modest accumulations of 2-5” by the Thursday morning mid-mountain report. Another 5-10” of snow is expected to fall during the day and evening along with increasing northwesterly winds before we may see a lull around midnight ahead of a wave embedded within the favorable and moist northwest flow.
Snowfall rates will increase soon after midnight and reach rates almost double that observed on Thursday. It should be snowing hard at report time, and with the 5-10” from the previous day, I would expect 8-16” of snow by the Friday morning report, based upon the latest weather forecast data which has decreased snow totals from earlier runs a bit.
So we should see some Steamboat Magic on Friday, where there are significant accumulations between report time and ski time. Northwest winds should increase in the morning and become gustier before snowfall is expected to taper off during the late morning as the embedded wave passes. But showers, some producing briefly moderate to heavy snowfall rates, should continue in the afternoon with the storm mostly over by the evening. Most of the 4-8” of snow reported Saturday morning should have fallen during the day Friday, though showers are expected to persist overnight.
Meanwhile, another storm develops in the Gulf of Alaska on Saturday and drops southward along the West Coast and splits on Sunday. We should see a break during the day Saturday before the northern part of the split brings a cold front through our area around Saturday night, with 2-5” of snow possible by the Sunday morning report. Though it is uncertain, we may also see some energy eject out of the southern part of the split storm and move over the front, which should restart light showers after a short break Sunday morning that last into Monday morning.
The last half of Monday into the first half of Tuesday look like the driest period of this upcoming week before another strong storm rounds the ridge of high pressure in the eastern Pacific and forces the southern part of the earlier split storm near our area by Tuesday night. Unsettled weather is forecast for Wednesday as this storm passes mostly to our south, with more cold air and snow possible after midweek depending upon the eventual track of the next storm.