Much colder with light snow likely for the weekend
Thursday, December 26, 2019
Behind the modest Christmas Day storm in Steamboat Springs yesterday, a mix of sun and intermittent snow showers will continue today before we see more sun for Friday morning. But a much colder air mass is forecast to settle over our area for the weekend and heading into the new year with snows likely on Saturday that could persist through Monday.
In hindsight, the Christmas Day storm was disappointing to me as there were indications in a couple of models over several cycles that three bands of snow would pass over the Steamboat Springs area; in fact only one passed through mid-morning which did produce a quick two inches of snow. The afternoon band looked threatening for a while, though all we saw were clouds on the upper mountain, with some sun in the South Valley, and the evening band failed to materialize.
Even though my forecast numbers did verify on the lowest end, that the shorter-range models over-predicted the later-day snowfall is troubling from a forecasting perspective. In broad terms, the storm placement to our south never produced the favorable northwest flow for our area, so the forecast was too reliant on the evolving dynamics of the storm in the generally unfavorable flow for our area.
Moving on, another Pacific storm is currently affecting southern California and will move across the Desert Southwest on Friday. Additionally, a separate fast-moving Pacific storm currently near Vancouver has mixed with some very cold air from Alaska and western Canada. From tonight and through the weekend, the Vancouver and Desert Southwest storms will interact in a complex and hard-to-predict fashion over the West. While snow amounts for our area could surprise to the upside or downside, the cold temperatures on Saturday, Sunday and Monday are more certain.
So, some sun Friday morning should give way to increasing clouds as the Desert Southwest storm moves across Arizona. Snow showers should get going Friday night as the first cold front from the Vancouver storm moves through, with 1-3” possible for the Saturday morning report. Temperatures should fall through the day in cold northerly flow, approaching around 0 F by the time the lifts stop turning on Saturday, along with continued light snow showers that would leave another several inches.
Snows will persist overnight and into Sunday morning, leaving 2-5” of powder for the quite cold Sunday morning report. While they may end for a time during the day Sunday, light snow is forecast again from Sunday afternoon through Monday morning, with 1-4” of snow possible for the still-cold Monday morning report.
We should see another cold Tuesday morning, though temperatures should moderate during the day, especially at the higher elevations. There may or may not be snow showers for New Years Eve as a good-looking storm from the Pacific Northwest approaches. This is currently forecast to bring accumulating snows to our area for New Years Day, and I hope to have more clarity on this storm by my next weather narrative on Sunday afternoon.
Forecast snow amounts increase for Christmas
Tuesday, December 24, 2019
A quick note to update my forecast from last Sunday for more snow. Shorter-range models have indicated the possibility of banded snowfall on Christmas Day over Steamboat Springs, which could create snowfall rates as high as 1” per hour at times tomorrow. The banding can occur when the usually broad and diffuse lift associated with an unstable atmosphere within a storm is concentrated along relatively narrow and roughly parallel bands, and can result in localized moderate to heavy precipitation at times.
I still expect the storm to get going this evening, with 1-4” expected by the Christmas Day ski report. But after a break early in the morning after the initial wave of the storm passes through, we should see sometimes moderate to even heavy snowfall at times from mid-morning through the afternoon leaving another 2-5” of snowfall at mid-mountain by the time the lifts stop turning.
While the heaviest snowfall will be over by around midnight on Wednesday, with another 1-4” overnight yielding 3-9” for the Thursday morning report, much lighter snows will continue through the day Thursday with only minor additional accumulations expected.
Drier air briefly works into northern Colorado on Friday before a quick moving Pacific wave mixes with some very cold air from Alaska and western Canada and brings sharply colder temperatures for the weekend. Currently, light snow showers are advertised for at least Saturday and possibly Sunday as well, but I’ll have more details on the weekend’s weather on my regular Thursday afternoon weather narrative.
Warm with increasing clouds ahead of a white Christmas
Sunday, December 22, 2019
Some morning clouds have given way to mostly sunny skies in Steamboat Springs this Sunday around noon, with the current temperature in town one degree above our average high of 27 F and the temperature at the top of the Steamboat Ski Area a balmy 37 F, accompanied by some breezy southwest winds.
The warm temperatures are a result of warm air being carried northeastward ahead of a large storm just off the northern California coast. The storm is expected to split tonight as additional Pacific energy approaches and forces the storm eastward on Monday and Tuesday. The evolution of this storm has varied within and between the weather forecast models over the last several days, making for an uncertain forecast. Right now, Monday looks similar to today, with Tuesday seeing increasingly thick cloud cover ahead of the storm in continued above normal temperatures. Snow showers are currently advertised to break out Tuesday evening, perhaps around midnight, with 1-4” of snow expected for the Christmas morning ski report as a cool front passes through.
Snow showers are expected to persist through Christmas Day into Thursday as additional Pacific energy interacts with the storm. Though generally of light intensity, there is a possibility of better snowfall for a time Wednesday afternoon and overnight as a wave of energy that is forecast to eject out of the storm may or may not pass close to our area. So there could be another 1-4” for the Thursday morning report.
A break in the unsettled weather is likely for later Thursday or Friday that extends through most of the upcoming weekend before significant weather forecast model disagreement appears. The American GFS want to keep the storm moving well to our south with a dry and cool forecast for the beginning of the next work week, while the European ECMWF hangs the storm far enough back to bring light snow chances back to our area. More details should be available by my next weather narrative on Thursday afternoon.
Dry with warming through the weekend
Thursday, December 19, 2019
The weather will stay dry in Steamboat Springs with continued warming through the Winter Solstice weekend, which occurs at 9:19 pm on Saturday and makes that night the longest of the year. Warm and pleasant weather will last through Monday before several waves of Pacific energy and moisture turn our weather unsettled starting around Tuesday, Christmas Eve day.
After a relatively warmer morning in town with a low temperature of 2 F this Thursday, just two degrees below average, an anemic and moisture-starved wave will pass over the Rocky mountains today, barely bringing even clouds to our area. However, some cool air associated with the wave will keep temperatures in check today and create another chilly morning in the Yampa Valley for Friday. But warming commences during the day and increases through the weekend and into Monday under mostly sunny skies as a ridge of high pressure builds over the West ahead of a Pacific storm expected to affect California late Saturday and Sunday.
The evolution of this storm has not been well-forecast so far, with a lot of inconsistencies both between and within successive weather forecast model prognoses. This is not unusual with storms off the West Coast that will be affected by additional upstream Pacific energy and are forecast to mix, to some degree, with cold air from western Canada. The differences arise from not only the paucity of data over the Pacific Ocean, but also how the weather forecast models incorporate those data.
This is a long way of saying that there is considerable uncertainty in the timing and strength of storms passing over our area as soon as Tuesday, Christmas Eve day. There is a lot of time for the weather forecast models to iron out their differences by my next weather narrative on Sunday afternoon, but currently the storm is expected to undergo some sort of split by the end of the weekend even as additional Pacific energy rounds the base of the storm.
Clouds will increase later Monday into Tuesday as moisture is drawn northward over our area in southwest flow ahead of the storm. Snow showers are currently advertised to break out during the day Tuesday and last overnight before ending by Christmas as a cool front passes through.
After a likely break on Thursday, another couple of storms are forecast for around the Thursday/Friday and Saturday/Sunday time frames, though their speed and track are too uncertain for a forecast at this time. Check back for my next weather narrative on Sunday afternoon for more details.
Quiet and cold weather with warming starting midweek
Sunday, December 15, 2019
The long-duration and well advertised snows have ended over the Steamboat Springs area this Sunday morning, with the Steamboat Ski Resort reporting three day totals of 22.5” of snow at mid-mountain and 27” up top. Cold temperatures are now observed behind the storm and are expected to last for the next couple of days before we see warming, first at the higher elevations, by later Tuesday and Wednesday. And other than some light snow showers during the day Monday and possibly on Thursday, quiet weather is expected through the upcoming week before the next possibly significant storm approaches the West Coast around late next weekend.
Colder overnight temperatures than recently observed were right at our average of 5 F this Sunday morning, with high temperatures over the next few days staying ten degrees or so below our average of 27 F thanks to the cold air mass behind the storm, fresh snow cover and low sun angle.
After a precipitation-free and partly sunny day today, a trailing and weak wave of energy and moisture will move over our area during the day Monday. Some light snow showers are possible at the higher elevations, possibly leaving several inches of snow during the day that would be reported Tuesday morning.
A ridge of high pressure then moves over our area for Tuesday and Wednesday, bringing plenty of sun and warming, first noted at the higher elevations. Mornings in the Yampa Valley will stay chilly with low temperatures around zero as the clear nights, light winds and fresh snow cover allow the ground to efficiently cool, and sets the stage for early-day temperature inversions, where the air is actually warmer higher up on the hill than it is in town.
The ridge will keep moving eastward thanks to a moisture-starved storm that will cross the central West Coast on Wednesday and move over our area on Thursday. At this point, not much more than some clouds and cooler daytime temperatures are expected before a stronger and longer-lasting ridge of high pressure builds over the Rocky Mountains for Friday and the weekend.
So, much of the Rocky Mountain region should see a beautiful and warm Friday extending through the following weekend. This looks to last into at least part of the following Monday before there is considerable uncertainty with respect to the next storm forecast to affect the West Coast around then. The weather forecast models indicate some sort of splitting storm, though the severity of the split and how additional upstream energy are handled is unknown at this time. I hope to have a better idea how this may affect our Christmas Eve day and Christmas by my next weather narrative on Thursday afternoon.
