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.