Thursday, December 12, 2019
Snows have started this Thursday morning in Steamboat Springs ahead of time, and will wax and wane over the next two and a half days leading to storm cycle accumulations that could total 16-32” by Saturday afternoon. The most most intense snowfall on Thursday night and then again from Friday night into Saturday morning will be accompanied by stout westerly to northwesterly winds and will make travel difficult to impossible over mountain passes. Much colder but drier air sweeps in behind the storm for Sunday and extending to midweek, with warming, especially at the higher elevations, expected for the remaining work week.
Note that I have just added some additional numerical guidance to the Snowalarm Home page that shows the temperature, wind and precipitation forecast from the Colorado Avalanche Information Center for the Steamboat Ski Area for both Thunderhead and the top of Mt. Werner over the next three days. This represents the high-resolution version of the weather forecast model that office runs every 6 hours, and is useful for getting an overview of a predicted storm. To access the data, click on ‘Precipitation Forecasts’ and scroll down the container until you see the ‘Latest CAIC Point Forecasts’ heading. Also, previous forecasts can be viewed with the ‘Previous forecast / Next forecast’ links at the bottom of the image and give a useful indication of how the forecast is trending. Note that the scale can change when navigating through successive forecasts. Be cautioned that this is one of many weather forecast models I review before making a forecast, and as such may have its own ‘opinion’ at times.
Back to the forecast, a strong Pacific jet stream is carrying subtropical moisture from around Hawaii inland and across our area. Lots of good things associated with this, including moisture and upward motion associated with the jet stream, several embedded waves within the flow and generally northwest flow which is good for orographic, or terrain-driven, atmospheric forcing over the Park mountain range. The relatively light snowfall will continue today leaving 2-4” at mid-mountain by close. However, an embedded wave brings a cool front through our area in favorable northwest flow early this evening, increasing snowfall rates to an inch or more per hour at times from sunset or so through the overnight. Along with the wind, travel will quickly become difficult to impossible tonight over the mountain passes. I would expect 5-10” overnight which would yield 7-14” of snow for the Friday morning report.
Snows are expected to at least decrease, or even end, during the day Friday, though continued windy conditions will keep travel difficult.
Snows pick up again and turn moderate to heavy Friday night and Saturday morning as a second embedded wave in northwest flow begins to move over our area. Travel will become more difficult or impossible again through that time as snowfall rates of an inch per hour or more occur at times along with continued windy northwest flow. Another 6-12” of snow is currently forecast for Saturday morning, with snowfall rates decreasing in the morning and tapering off in the afternoon. But we could see another 3-6” during the day which would make the storm total 16-32” by the time the lifts stop turning Saturday.
Though our significant snowfall will end around then, a third colder wave is forecast to take a more southern route through the Rocky Mountains, bringing significant snowfall to southern Colorado. There is some uncertainty with the track of this part of the storm, but right now we could see some light snowfall Saturday night associated with a strong cold front that will bring much colder temperatures for Sunday that will extend into the work week.
At this point, we will be on the edge of additional snow showers on Sunday, but the sun should return for a chilly and dry Monday, Tuesday and possibly some of Wednesday before warmer air associated with a ridge of high pressure behind the storm moves over our area by Wednesday.
Sunday, December 8, 2019
Clouds and a few snow showers have greeted Steamboat Springs residents this Sunday morning ahead of a storm for this afternoon and tonight. Not much more snow is expected after Monday morning until a possible long-duration event begins around Friday and extends through next weekend.
Currently, a batch of showers is traversing across western Utah and is associated with the northern part of a split storm that extends into southern California. While the storm will continue to split today, our area should see good snowfall this afternoon and overnight as the northern part of the storm swings through.
While snows may have a tough time getting started this morning, we should see some moderate to possibly heavy snowfall for a time this afternoon and into the evening as a weak cool front ahead our portion of the storm turns winds to be from the southwest to the west and eventually the northwest. Temperatures may be warm enough ahead of the front for some mixed rain/snow in town that should turn to all snow as precipitation rates increase in the afternoon, especially around sunset. Travel may be difficult for a short time, especially at pass level, during the heavier showers.
While snowfall intensities will decrease for a time this evening, a stronger cold front is forecast to pass through our area within several hours of midnight. Snowfall should increase around the front, and become lighter and fluffier before tapering off during Monday morning. I would expect 6-12” of snow to be reported on the Monday morning mid-mountain report, with a bit more than that at the top as the orographic, or terrain-driven snowfall in favorable northwest flow favors the higher elevations.
Unfortunately, the split storm will not allow further accumulations later Monday into Tuesday as my forecast last Thursday indicated was possible. So only 1-4” of snow is now expected after the Monday morning report and before noon.
While a ridge of high pressure temporarily builds over our area on Tuesday for a nice day, a weak and moisture-starved storm is forecast to pass through the ridge on Wednesday, bringing some clouds but likely no precipitation.
However, this does open the door for a steady stream of Pacific energy and moisture to move over our area as soon as Friday. So after a pleasant Thursday, a long-duration precipitation event is advertised to begin by the end of the work week and last through the weekend. Generally light to perhaps moderate snows will wax and wane on Friday and Saturday in the relatively warm temperatures as difficult-to-time waves of energy periodically pass through in the moisture-laden atmosphere.
A stronger wave is advertised to mix with some cool air from western Canada near the end of the event, currently timed for around Sunday, which would create the heaviest snowfall rates and lightest snow densities. If this occurs, it would make for some great skiing and be the cherry on top of several days of snowfall.
Thursday, December 5, 2019
Snows have been falling at a moderate rate this Thursday morning in Steamboat Springs, with 5” being reported at mid-mountain and 6” up top on the 11 am snow report update. A bit more snow can be expected through the rest of today before snows end tonight. A couple of nice days are forecast for Friday and Saturday before a long-duration snow event with significant accumulations is advertised from Saturday night through Tuesday.
Today, a relatively warm storm is traversing over Colorado and is the remnants of the southern part of the split storm that passed over our area earlier in the week. Snows will continue into the evening with up to an inch or two of additional accumulations possible.
Behind the storm and ahead of our next Pacific storm, mostly sunny skies and warming temperatures are forecast for Friday and Saturday as a ridge of high pressure quickly moves over the Rocky Mountains. High temperatures on Friday should be several degrees above our average high of 30 F, with high temperatures for Saturday five to ten degrees above that average.
Meanwhile, a large Pacific storm currently off the West Coast is forecast to make landfall late Friday night or early Saturday morning and move across the Great Basin on Sunday as it mixes with some cold air drawn southward from western Canada. Additionally, the storm looks to incorporate subtropical moisture on Saturday in the southwesterly flow ahead of the storm, creating a long-duration snow event that will begin late Saturday or early Sunday and last through Tuesday.
Details are still evolving with this powerful storm, but right now it looks like we will see two main waves of significant snowfall; the first during the day Sunday in the warmer part of the storm and the second from Sunday night through some of Monday in the colder part of the storm. This second part of the storm is currently the most uncertain, not only because if is later in the forecast period, but also because there is weather forecast model disagreement on the amount of energy in the southern part of the storm.
While there could be a small amount of snow on the Sunday morning report, we could see 6-12” of relatively dense snow during the day and through the evening on Sunday in the generally westerly flow ahead of the parent storm. Around Sunday night or early Monday morning, a cold front is expected to pass through the area, lowering snow densities and creating some light and fluffy powder that will ski great on top of the denser layer of snow underneath.
There may be a break in snowfall for a time later Monday, but orographic, or terrain-driven, snow showers, which occur in our case when air is lifted by the Park mountain range, will occur from Monday night through Tuesday in the favorable cold, moist and unstable northwest flow.
A couple of days break is currently advertised for around midweek before some sort of storm may bring snows back to our area around Thursday.
Wednesday, December 4, 2019
My last Sunday weather forecast talked about a storm crossing the Great Basin on this Wednesday. Initially weather forecast models had us in clouds with the precipitation staying to our south. The storm has fortunately trended further north in subsequent model runs, and it now looks like the Steamboat Springs area will see snows from early Thursday morning through the day.
The further northward track of the storm brings a cool front through north central Colorado early on Thursday. There may be a modicum of snow on the Thursday morning report, but most of it will fall during the day, with 3-6” of snow expected at mid-mountain by the evening.
We are still on track for warmer and sunnier weather for Friday and Saturday before the next Pacific storm affects our area starting on Sunday. Stay tuned for my regularly scheduled weather narrative on Thursday afternoon for more details on this possibly significant storm.
Sunday, December 1, 2019
After the snow, wind and cold of Saturday, a warmer but still crisp, bluebird day is gracing Steamboat Springs early this Sunday afternoon. Temperatures will warm further for Monday even under some increasing clouds later in the day ahead of a grazing storm that will bring a chance of snow showers, greatest at the higher elevations, from Monday night through the first half of Tuesday. Another storm around Thursday looks to pass too far south of our area for much besides increased cloudiness before mostly sunny skies and warm temperatures end the work week and start the following weekend.
Though the first part of the last storm under-delivered for reasons I’m still trying to understand, the wind and snow came on schedule for the second part of the storm, with 5” of snow falling at mid-mountain during the day Saturday and temperatures at the top of Mt. Werner struggling to touch 4 F during daylight hours.
But we now see a cool and sunny day for the start of the Northern Hemisphere’s meteorological winter, which includes the most wintry months of December, January and February. Monday will dawn with cold temperatures within five degrees of our average low of 9 F, rising under mostly sunny skies to five to ten degrees above our average high of 32 F as a ridge of high pressure moves overhead.
Meanwhile, a storm off the West Coast splits today, with the northern part racing across the northern Rockies on Monday and grazing northern Colorado in northwest flow with some energy and moisture. Snow showers will become likely at the higher elevations by Monday night and last into Tuesday, with weather forecast models waffling on the duration and intensity of the showers. There could be as much as 1-4” of snow by the Tuesday morning report with that much again Tuesday morning after the report, though those reflect the more optimistic forecast at this time.
Even if showers end early on Tuesday, clouds will persist through the day and overnight as the southern part of today’s split storm off the West Coast is forced eastward across the Great Basin on Wednesday by another incoming Pacific storm. Notably, this Pacific storm will likely affect our area during the second half of the upcoming weekend.
But first, the Great Basin storm looks to be too far south of northern Colorado for precipitation, though more clouds will be in store for our area later Wednesday and Thursday as moisture ahead of and behind the storm overspreads our area.
A ridge of high pressure then briefly moves overhead for a mostly sunny and warm Friday. While the dry weather will extend into some of Saturday, that upstream Pacific storm is forecast to make landfall during the weekend. The timing and evolution of this storm will likely change over the coming days, but significant snowfall for our area is possible around the second half of next weekend or early the following workweek. More details will be forthcoming in my next twice-weekly weather narrative on Thursday afternoon.