Snowy week ahead
Wednesday, February 3, 2021
The first in a series of advertised storms arrived this afternoon, courtesy of a snow squall, and Steamboat Springs is currently seeing light to moderate snow late this Thursday afternoon. Snows are possible for every day during the upcoming week, with the heaviest and most persistent snow forecast for Friday and to a lesser extent Friday night.
The main part of the storm today is still back in Utah, so snow will continue through the night. The storm is about 6 hours slower than I originally thought in the last weather narrative, so the expected snowfall for the Thursday morning report is now in the 4-8” range.
As the storm departs our area on Thursday, we will be left with persistent northwest flow between a ridge of high pressure over the Gulf of Alaska and a deep and cold area of low pressure over the East and the Midwest. The Park mountain range just east of Steamboat Springs is favored under this regime, which is forecast to last through upcoming week, so expect some snowfall for most of the days as the air is forced up the slope of the mountains and orographic, or terrain-driven, snowfall ensues.
Waves of energy and moisture will periodically pass overhead and increase snowfall rates, with one potent wave passing overhead on Friday and Friday night. We may see several more inches during the day Thursday before snows pick up Thursday night followed by periods of moderate to heavy snow on Friday and Friday night, likely most intense on Friday afternoon.
If weather model forecasts hold, we could see 3-6” of snow on the Friday morning report and 8-16” by Saturday morning, with more than half of that falling during the day Friday. Snow will continue at lesser rates Saturday morning before tapering off in the afternoon and overnight.
Though we will see a break on Sunday between waves, it is not clear if snows will stop or just become very light. And another couple of waves may move overhead or nearby on Monday and possibly Wednesday, though that may change as these impulses are hard to time since they are embedded in fast flow from the sparsely observed Pacific.
The setup for this upcoming week is ideal for our area, though our eventual snowfall will be determined by how long we can stay in the moist northwest flow. Though weather forecast models agree on the wave for around Monday, they disagree on whether the ridge of high pressure over the Gulf of Alaska moves toward our area by midweek and deflects the storm track to our northeast, like the European ECMWF, or the ridge stays put and allows another wave to pass overhead in northwest flow, like the American GFS.
The storm track will be determined by the outcome of the battle between the warm air under the ridge of high pressure in the Gulf of Alaska and the very cold air over the Midwest and East. Eventually, both weather models do have the ridge moving inland late in the work week or the following weekend, though it is accompanied by fast westerly flow from the Pacific moving through the ridge, and this weather pattern can also be productive for the Rockies, especially if low-level cold air can hang around.
My next scheduled weather narrative is on Sunday afternoon, and I’ll have some hopefully impressive storm totals to talk about as well as discuss the additional snowfall expected during the following work week.
Dry weather ahead of storm cycle that starts midweek
Sunday, January 31, 2021
A temperature of 23 F at the Bob Adams airport, 17 F at the top of Mt. Werner and bluebird skies are over the Steamboat Springs area this Sunday noon. Warm and dry weather with lots of sun the next few days will be followed by a wet and very cold winter storm cycle that starts later Wednesday and continues into the weekend.
The Steamboat Ski Area is reporting 4.5” at mid-mountain and 11” up top from the storm that started early Saturday morning and ended in the afternoon. Though the updated phone reports during the day yesterday and the Steamboat Powdercam indicated otherwise, somehow the upper mountain totals this morning are correct and consistent with the excellent powder skiing yesterday afternoon.
A ridge of high pressure has built over the West behind the storm and ahead of our next one currently spinning in the Gulf of Alaska. The storm is in the process of mixing with some very cold air sourced from the North Pole and is bringing precipitation to the Pacific Northwest and northern California.
The evolution of the storm is still uncertain, as weather forecast models have been disagreeing with both themselves and each other. It now appears that the storm will undergo some sort of split early in the work week as it elongates along the West Coast, and contrary to most splitting storms, this split might actually be good for our area as it might divert some of the moisture from the storm around the Sierra Nevada mountain range and leave more for us.
Furthermore, it appears the majority of the storm energy will be in the northern branch, with the southern branch possibly forming an eddy that may get dragged along with the northern branch, similar to the American GFS, or get left behind for a few days west of the Baja coast as indicated in the latest European ECMWF Eventually, the southern branch does appear to bring some moisture into our area, though it is not clear if it is early or late in the storm cycle.
Current forecasts indicate moderate to heavy snowfall when the cold front associated with the northern branch of the split moves through our area later Wednesday. We may see lighter snowfall ahead of the cold front, and it does looks like we will see a windy period with winds from the west when the front moves through before it subsides a bit as the winds turn to be from the northwest behind the front.
By Thursday morning, we could be looking at 6-12” of snowfall, though making a snowfall forecast with such an uncertain evolution of the storm may be hazardous to my credibility!
Though we are forecast to be in favorable northwest flow through the weekend, there is dry air lurking to the southwest as a ridge of high pressure builds over the West Coast. Our area will be in the battle zone between warm and dry weather to the southwest, depending on what happens if that Baja eddy develops, and very cold air to our north. Ripples in the northwest flow will allow storms to track overhead, with breaks in the snow likely between the waves of energy and moisture.
Current forecasts have a short break in the snows around Thursday before a Pacific storm traveling through the Gulf of Alaska and over the top of the West Coast ridge mixes with some very cold air from western Canada and moves over our area around Friday. This has the potential to generate another round of significant snows as we head into the weekend.
I’ll stop talking about uncertainty for now, and caution to be prepared for a cold and wet storm cycle starting midweek and lasting into the weekend. Travel will almost certainly be difficult, or even impossible at times, so stay tuned to my next weather narrative, which I may publish on Wednesday, a day earlier than usual, as the weather pattern becomes clearer.
Modest storm on Saturday with major storm possible midweek
Thursday, January 28, 2021
Temperatures have warmed considerably in Steamboat Springs late this Thursday morning compared to the last few days with 33 F reported at the Bob Adams Airport and 28 F at the top of Mt. Werner. Warm and dry weather is expected for today and tomorrow before a quick-moving storm brings 4-8” of snow from Friday night though Saturday night. Warm and dry weather returns for Sunday and lasts until a possibly large, cold, wet and complex storm affects our area starting around midweek.
Some eye-popping totals have been reported by the California resorts this morning, with a standout of 45” in the past 24 hours at Mammoth Mountain! That storm is being forced eastward by another storm currently over the Aleutian Islands, with the remnants crossing the southern Great Basin and moving over our area from Friday night through Saturday night. Winds from the southwest ahead of the storm have brought much warmer temperatures to our area today and will for tomorrow as well.
While we will see a mix of sun and clouds over the next two days, winds from the southwest will become breezy and clouds will increase in earnest later Friday before snowfall begins Friday night. Depending on the eventual timing, We may see an inch or two for the Saturday morning report with 3-6” of continued snowfall during the day as winds shift to be from our favored northwest direction and temperatures cool, with snowfall tapering off during Saturday evening.
The sun returns on Sunday with warm temperatures as a ridge of high pressure builds over the West ahead of the developing Aleutian storm. That storm is forecast to mix with some very cold air from the North Pole as it traverses the Gulf of Alaska late in the weekend and will bring heavy precipitation first to the Pacific Northwest and then California by Tuesday.
While weather forecast models agree on that storm eventually moving inland and affecting our area around Wednesday or Thursday, there are differences in the evolution and timing of the storm that need to be worked out over the coming days. Generally, this looks to be a cold and wet storm that will be followed by additional impulses of energy, moisture and cold air. This is likely to be the best storm cycle of our season so far, and I’ll have a more specific forecast in my next regularly scheduled weather narrative on Sunday afternoon.
Light snows to start the week
Sunday, January 24, 2021
Mostly sunny skies and a temperature of 24 F are over the Steamboat Springs area this Sunday noon. A couple of storms will bring light snows and cooler temperatures to our area on Monday and Tuesday ahead of dry weather and warming temperatures for the rest of the work week. A modest storm is then forecast for the following weekend.
Snow totals from Friday morning through this morning totaled 6” at mid-mountain and 11” up top in the generally southwest flow associated with the storms. While Steamboat is most favored with northwest flow, the location of the stationary front, some instability and storm energy was sufficient for a modest storm that produced dense snowfall in relatively warm temperatures.
Skies have cleared ahead of another couple of storms that will pass to our south on Monday and Tuesday; in fact the cloud shield associated with the first storm is currently visible to our south. Clouds will increase later today with light snow possible today and tomorrow, leaving 1-4” by Monday night.
The storm for Tuesday is currently sliding down the Pacific Northwest coast after mixing with some cold air from western Canada and is forecast to move along the California coast tomorrow before turning eastward and moving across the Desert Southwest on Tuesday. We’ll see a break in the light snowfall for Monday night and early Tuesday before light snow is again possible later Tuesday. Cooler temperatures will accompany the storm before the snow ends by Wednesday morning and temperatures start to warm by the afternoon, with another 1-4” possible for the morning report
A potent winter storm is then forecast to develop off the West Coast by midweek as a storm currently near the Aleutian Islands mixes with some very cold air from western Canada as it travels through the Gulf of Alaska on Tuesday. A ridge of high pressure is forecast to build over our area ahead of the storm which starts our warming later Wednesday and continues warm and dry weather until the end of the work week.
The storm off the West Coast is forecast to be forced inland on Friday by an even stronger and colder upstream storm, and will move over our area in some form for the weekend. Timing and strength are still up for debate, so stay tuned to my next regularly scheduled weather narrative on Thursday afternoon for more details on the weekend storm and snowfall guesses.
And for what its worth, that stronger and colder Aleutian storm is forecast to eventually move over our area during the following work week, and is currently looking quite promising with plenty of moisture and cold air.
Snowy weather to start the weekend
Thursday, January 21, 2021
A mix of sun and clouds are over the Steamboat Springs area this Thursday noon with temperatures several degrees above our average of 27 F and rising. Several storms are forecast for our area over the upcoming week, with the best-looking storm on tap for Saturday.
As discussed in the previous couple of weather narratives, the northern hemisphere atmosphere is transitioning to a more active pattern for the West as a ridge of high pressure once over the inter-mountain region is now over the Gulf of Alaska. Pacific storms will now move over the ridge of high pressure and move southward along the West Coast, with some mixing with the cold air present over Canada.
Our next weather-maker is currently moving southward off the Pacific Northwest coast as a chunk of cold air over the Canadian Plains moves southward into the Northern Rockies and Midwest. The Pacific Northwest storm is forecast to move southward along the West Coast on Friday and Saturday before being forced eastward on Sunday by another Pacific storm moving down the ridge of high pressure over the Gulf of Alaska.
If this sounds complicated, it is, and leads to weather forecast uncertainty as there are a lot of moving pieces that will influence our weather. Generally, a stationary front separating the colder air to our north from the warmer air brought northward in the southwest flow ahead of the West Coast storm will waver near or over our area on Friday and Saturday.
While the mix of sun, clouds and even snow showers over us today are effects from the Baja eddy to our south that was discussed in the last weather narrative, the snows that are expected to start as early as tonight are the result of pieces of energy ejecting out of the West Coast storm and traveling over the stationary front.
Several waves of energy are forecast to be ejected from tonight through Saturday night, with the strongest timed for the first half of Saturday. Additionally, it appears we will be mostly on the warm side of the stationary front until another Pacific storm forces the West Coast storm inland and allows the cooler air to the north of the front to infiltrate our area around Saturday night. By then, the storm will be mostly over, so it looks like we will see relatively wet and dense snowfall for most of the event.
Snow showers may begin as early as tonight and continue through Friday before the snows become more persistent and heavier overnight Friday and Saturday. We could see an inch by the Friday morning report and another inch or two during the day in advance of the strongest wave, with the 3-6” overnight Friday yielding 4-8” for the Saturday morning report. And the snowfall will continue on Saturday, likely heaviest in the morning and making travel difficult over Rabbit Ears Pass, with another 3-6” expected before the lifts stop turning.
Though snowfall will decrease overnight as cooler air filters in behind the storm, there may be another inch or two of drier snowfall overnight that would yield 4-8” for the cooler Sunday morning report. I’ve recently added simulated radar maps, similar to the one shown to the right, from the shortest-range weather forecast model here so that folks can easily visualize the forecast. While the model is normally run for only 18 hours, there are four times per day that the model is run for 48 hours, and you can see the evolution of the forecast by first clicking the View All button next to the Rapid Refresh radar maps and then clicking the Animate box in the upper left hand corner of the page.
Meanwhile, that next Pacific storm is forecast to be quite a bit colder as it mixes with cold western Canadian air early in the weekend before dropping down the West Coast late in the weekend and ejecting the preceding storm across the Desert Southwest early in the work week. The ejecting storm may be close enough to bring some snow showers to our area on Sunday, though the eventual track will determine how showery it is and whether we see any sun.
A third stronger storm slides down the Gulf of Alaska ridge on Tuesday and forces that second West Coast storm eastward along a similar, but perhaps further north track as compared to the previous storm. There will again be a chance of snow showers on both Monday and a cooler Tuesday, depending upon the eventual track and proximity of the storm, before drier air behind the storm overspreads our area on Wednesday.
That third stronger storm is currently forecast to take a further westward track before eventually turning inland around the end of the work week thanks to yet another Pacific storm rounding that ridge of high pressure over the eastern Pacific. There looks to be a break in this active pattern as a transient ridge of high pressure builds over the Rockies on Thursday and Friday as the southwest flow ahead of the storm brings dry air and warming temperatures northward. But that currently looks to be short-lived as that third storm is forecast to move near our area during the following weekend.
Tune in for my next regularly scheduled weather narrative on Sunday afternoon as I’ll review the hopefully productive Saturday storm and have a better idea of how much snow looks likely from our early work week storms.