Monday, December 5, 2016
Cold air sourced from the North Pole, euphemistically referred to as Big Blue, will invade our area over the next few days making Tuesday, Wednesday and Thursday morning the coldest days of the season so far. A wave in northwest flow is currently crossing the Pacific Northwest coast and will bring bitter cold, wind and some moisture to begin snow again starting Tuesday afternoon and lasting through some of the day Wednesday. Even though the moisture content of the air is modest due to the cold temperatures, 4-8” of very light fluffy snow may be reported on the Wednesday morning mid-mountain ski report.
But temperature may reach as low as the minus teens for Wednesday and Thursday mornings with highs in the single digits for Wednesday. The light snows will end by Wednesday afternoon after another inch or two possible, with peaks of sun in the valley making it feel slightly less cold.
A transient flat ridge follows for Thursday and Friday, bringing welcomed warming and enough wind to scour out the valley inversions and bring temperatures back closer to normal. Though there will be sun during the first part of the day Thursday, there will be enough moisture embedded in the brisk northwest flow to bring the threat of light snow showers back to the region later Thursday.
Hard to define and time waves in a proximate jet stream oriented west-northwest are forecast to pass around or north of the Steamboat Springs area for Friday and Saturday, bringing periods of moderate to heavy snowfall at times and likely leaving significant accumulations over the 2 days.
A break in snowfall is currently timed for Sunday before another grazing wave begins snowfall again by late in the day. In fact, current model simulations have the jet stream close enough to keep the threat of snowfall going for most of the following week. However, small variations in the location of the jet as well as the moisture contained within it make for a rather uncertain forecast with large variations in predicted snowfall likely until a model consensus emerges.
Friday, December 2, 2016
A low to our south and a large storm in the Gulf of Alaska will affect our weather over the next week. The southwest flow from the low to our south has directed moisture and light snow showers over our area that will persist through the night with only an inch or two of accumulations.
Meanwhile, the atmospheric jet stream is currently punching into the Pacific Northwest bringing copious precipitation as energy begins to be ejected from the Gulf of Alaska storm. We may see some very light snow showers on Saturday afternoon and overnight as energy in the southern end of the jet stream grazes northern Colorado.
While the northwest and northern U.S. Rockies will see the bulk of precipitation from this storm, Colorado is tantalizingly close to some action, and the models have been struggling with the proximity of the jet stream over these last few days. What appeared to be a very promising storm a few days ago now looks to deliver more cold than snow early next week after a flat ridge moves over the Steamboat Springs area on Sunday and briefly warms temperatures.
Snow showers should start by early Monday morning as the main part of the storm approaches from the northwest. Snows will generally be light until a strong cold front blasts through the area on Monday, likely accompanied with a burst of snow that quickly ends behind the front.
Very cold air will then invade our area making Tuesday and Wednesday the coldest days of the season so far. There is another wave in northwest flow that looks to bring more snow showers to Colorado on Tuesday and Wednesday, and models are wavering on the exact track, which will likely change as we move closer to the event. Right now, some dry air is forecast to spread over the Steamboat Springs area on Tuesday, keeping snows to our south, before light snow showers visit our area Tuesday night and early Wednesday.
A transient ridge follows for Thursday and Friday, bringing warming that will be most noticeable at the mid and higher elevations as developing inversions keep the valleys chilly. More grazing waves are forecast for Saturday and the following Monday, but I expect the forecast to change as models get a better handle on two features that will likely determine our weather over the next 2 weeks; a sharp ridge over the Bering Sea between Russia and Alaska and cold air from western Canada moving westward that may interact with that ridge as well as possible undercutting energy from Asia.
Monday, November 28, 2016
Energy spinning around a closed low in the Dakotas will combine with a shortwave to our west in northwest flow to bring periods of snow and reinforcing surges of cold air to the Steamboat Springs area through tomorrow. Short range models have snows intensifying for a time later this evening and again soon after sunrise as a couple of waves move through. I still expect 3-6” to be reported Tuesday morning.
Snows will become more showery through a cold day and night before finally ending by Wednesday morning. Though accumulating snows end with 1-4” expected for a cold Wednesday morning report, there may be isolated showers on Wednesday as Colorado will be caught between energy to our northwest and the low to our northeast which eventually is forecast to be over the Great Lakes on Wednesday.
Another wave in northwest flow crosses the Pacific Northwest coast Wednesday and could affect our weather on Thursday and Friday as it travels across the Great Basin. Though models agree that this wave will elongate to the south when combined with additional upstream energy, there is disagreement with respect to how much energy is diverted southward and the eventual track of that energy.
For the Steamboat Springs area, light snow showers could get going again on Thursday if the Pacific Northwest energy is in our proximity. Showers could persist overnight and through the day Friday with light accumulations if the more favorable solution verifies, otherwise showers will be less numerous or even non-existent.
Colorado is forecast to be on the southern edge of the jet stream through the weekend, with some clouds persisting on Saturday and a chance of light showers on Sunday before another Pacific Northwest storm approaches our area early in the next work week.
Friday, November 25, 2016
A building ridge brings dry air, sunny conditions and warming temperatures to the Steamboat Springs area today and Saturday. Valleys will start out cold in the mornings due to the formation of temperature inversions encouraged by the the season’s low sun angle and snowfall on the ground.
Three waves of energy will bring cold and snow for Sunday through overnight Tuesday. The first wave will cross the southern California coast Saturday afternoon. Concurrently, the second wave will be forced southward along the West Coast from the Gulf of Alaska by an approaching third wave that will also move through the Gulf of Alaska.
Snows should start by Sunday morning as the first wave is forced northeastward across the Great Basin Saturday night and over our area on Sunday by the second wave. Temperatures look cold enough for an all-snow event as the first storm forms a closed low near the Wyoming - Nebraska border by Sunday night. There may be a burst of snow with the front followed by light to moderate snows in the cool, moist and unstable northwest flow on the backside of the closed low to our northeast that makes travel difficult later in the day. Snows are expected to continue through the overnight Sunday hours, and though amounts are uncertain due to the complicated nature of the storms, we could see 5-10” on the hill by Monday morning.
While the bulk of the second wave dives towards the New Mexico - Mexico border by Monday, some energy does travel over the Rocky Mountains and phases with additional energy traveling around the closed low which is forecast to be around Minnesota by then. I would expect light snowfall for most of the day Monday with occasional heavier showers as lobes of energy from both the northern and southern systems travel over the area. Another 3-6” of snow by Tuesday morning is possible.
The third wave brings much colder air and takes a more inland route, diving southeastward across the Great Basin on Monday. We will see the cold air from this wave starting on Tuesday and accompanied by light low-density snowfall that will last into Wednesday morning. This could leave another 1-4” for the Wednesday morning mid-mountain report.
While Wednesday will start quite cold, we will be in-between systems before another wave from the northwest is forecast by the American GFS to bring light snow showers to our area as soon as Thursday morning. This wave is forecast to split around Colorado minimizing the amount of snow but keeping the unsettled and cool meteorological conditions around through the end of the work week.
Monday, November 21, 2016
A warm southwest flow ahead of the next storm brought a quick round of showers early this morning and is expected to do the same around sunset. There was some thunder associated with the storm earlier today down south and that threat will be present for the rest of the day as the bands of precipitation move northward.
But it appears the bulk of the warm precipitation will stay to our south and west until cooler air courtesy of the loosely connected northern portion of the storm moves through our area tonight and winds veer to our favored northwest direction. There is some uncertainty as the bands of heaviest precipitation are forecast to be close, and if they track a but further east than currently predicted, we may receive periods of moderate to heavy precipitation with dense snow at the higher elevations around midnight.
Regardless, behind these bands, we will likely see light to moderate snowfall down to the base with the cooler northwest flow around the several hours before and after sunrise before the snows turn more showery during the day Tuesday and end in the late afternoon or evening.
Snowfall amounts may be in the 4-8” range by Tuesday afternoon with the higher totals at the higher elevations due to the colder temperatures.
A transient ridge is forecast for Wednesday bringing a nice mostly sunny and warm Opening Day with fresh snow.
A quick-moving wave with colder air than the Tuesday storm passes over northern Colorado Wednesday night, and models have trended a bit stronger with more generous precipitation. We could see 3-6” of snow between midnight on Wednesday and noon on Thanksgiving Day before a building ridge brings dry air, sunny conditions and warming temperatures for Friday and Saturday.
Models now have another moderate storm for Sunday, a brief break on Monday and are advertising a much larger and more impressive storm for early in the next work week.