Temperatures to slowly warm under mostly clear skies
Sunday, December 1, 2024
Clear skies and temperatures in the twenties are over the Steamboat Springs area this Sunday noon on the first day of December, the start of meteorological winter. Quiet and cool weather will persist through the workweek with little hope for precipitation until or just after next weekend.
A ridge of high pressure is over most of the West Coast while a deep and broad area of low pressure is over eastern North America. Our area is under predominantly northwest flow as light winds round the top of the ridge and move toward the eastern low pressure area. Though an area of dry low pressure is slowly spinning well off the southern California coast, weather forecast models have that staying south of our area as it moves inland through the workweek.
The clear skies, light winds and fresh snow cover have led to a strong temperature inversion, where higher elevations are warmer than the cold Yampa Valley bottom. For example, the low temperature at the Storm Peak Lab near the top of the Steamboat Ski Resort was 15 F this morning compared to one degree at my weather station near the resort’s base. At least the low temperature this morning was warmer than the frigid -7 F Saturday morning and -10 F on Friday morning!
Temperature guidance is notoriously too warm under these conditions as weather forecast models struggle with the low-level details, with the low temperatures running ten to fifteen degree below forecast and high temperatures around five degrees below forecast. So we are probably looking at continued single digit lows, about five to ten degrees below our average of 11 F and mid-thirty degree highs, just above our average of 34 F.
Ironically, the best chance of breaking a persistent inversion is an incoming cold front, as winds associated with the front mechanically mix the low-level atmosphere and bring the warmer air aloft down to the surface. While only weak and dry grazing waves in the northwest flow are forecast for Monday and Wednesday, a better chance of some mixing may exist for the end of the work week as a wave of energy is ejected from a strong storm forecast to develop over the Aleutian Islands.
While this currently looks weak, dry and disorganized, a wetter and stronger wave from the Aleutian storm may bring a storm through our region near the end of the weekend or the beginning of the following workweek. So enjoy the sunny but cool week and I’ll have more details about the incoming storm in my next regularly scheduled weather narrative on Thursday afternoon.
Dry and warmer weather to arrive for the weekend
Thursday, November 28, 2024
After some magical flurries early this Thanksgiving morning in Steamboat Springs, the sun has appeared, illuminating a sparkling wintry landscape. Sixteen inches was officially recorded at the downtown weather station by Wednesday morning with around two feet at the Steamboat Ski Resort by Wednesday afternoon. The cold air behind the storm will keep the high temperatures in town in the twenties today before they slowly rise through the weekend toward forty degrees by Monday under mostly sunny skies.
The atmospheric river and the remnants of the bomb cyclone delivered as promised, with the sixteen inches of snow in town since Monday night containing almost one and a half inches of liquid water for a very dense 10:1 snow water equivalent. In hindsight, the storm arrived about six hours earlier than forecast in my last weather narrative, making Tuesday morning snowier than expected while allowing the storm to end earlier on Wednesday. And while the snow totals forecast for the Steamboat Ski Area were close, the snowfall in town was under-predicted by around fifty percent, likely due to the stronger-than-forecast forcing from the former bomb cyclone.
A ridge of high pressure currently over the eastern Pacific ahead of a large storm developing south of the Aleutian Islands will slowly strengthen as it moves eastward through the weekend. Combined with a deep area of low pressure over eastern North America, winds from the northwest will carry predominantly dry and warmer air overhead through the weekend. A weak wave embedded within this flow will bring some clouds overhead on Saturday, especially in the afternoon, but that will not stop high temperatures forecast to be in the mid-twenties today from slowly rising through the weekend toward forty degrees on Monday, compared to our average of 36 F today and 34 F on Monday.
The dry and warmer-than-average weather looks to continue through the workweek, though there is some hope that we may see some precipitation by next weekend or soon after. However, there is considerable uncertainty in the longer-range forecast, so enjoy the beautiful weather for the long Thanksgiving Day weekend and check back to my next regularly scheduled weather narrative on Sunday afternoon for more details.
Monster storm to start Tuesday after moderate storm today
Sunday, November 24, 2024
Light snow is falling in Steamboat Springs late this Sunday morning with temperatures hovering in the low thirties. A cold front will bring moderate snowfall accumulations through tonight preceding a break in the weather on Monday. But it will be short-lived as moderate to heavy snows on Tuesday and Wednesday bring significant accumulations to all elevations making travel difficult or even impossible at times over Rabbit Ears Pass.
A wave of energy ejected from the decaying bomb cyclone off the Pacific Northwest coast will combine with the remnants of an atmospheric river and bring a cold front and moderate snow through our area this afternoon and evening. Total accumulations should be between four and eight inches at and above mid-mountain with one to four inches in town.
A break in the weather on Monday will bring mostly sunny skies with high temperatures in the mid-thirties, around our average of 37 F. But don’t be fooled by the nice day; the Pacific Northwest storm is forecast to move slowly south through Monday before grudgingly being forced eastward by a wave of energy and cold air moving across Alaska. Additionally, another atmospheric river moving across the southern Sierras, much wetter than the last, will be ingested by the storm as it approaches our area early Tuesday.
Light snow should start falling after midnight on Monday before the firehose of moisture produces moderate to heavy snows thanks to westerly winds impinging on the Park Range. Snowfall rates around an inch per hour and increasing winds with gusts above 30 mph will make travel hazardous over Rabbit Ears Pass by Tuesday afternoon.
The storm will stretch to the southwest as it moves across the Great Basin later Tuesday, bringing a moderate cold front that will force even heavier snowfall rates approaching two inches per hour at times. Travel over Rabbit Ears Pass will likely degrade further and perhaps become impossible from later Tuesday into Wednesday morning.
The heaviest snowfall should be over by Wednesday afternoon, though snowfall will likely linger through Thanksgiving morning as the rest of the stretched storm passes overhead. Total snowfall accumulations will be impressive, with mid-mountain and above seeing 1-2′ by Wednesday morning and another 6-12” by Thanksgiving morning. The warmer temperatures in town, especially Tuesday afternoon with high temperatures just above freezing, will limit the accumulations to 3-6” by Wednesday morning with another 1-4” during the day and overnight.
There may be some sun by Thanksgiving afternoon illuminating the new wintry landscape, especially in town, as a ridge of high pressure ahead of a strong storm forecast to develop south of the Aleutian Islands moves eastward. There is some weather forecast model uncertainty regarding a wave moving around the periphery of the ridge that may bring cooler air and snow showers by Friday or Saturday, but I’ll have more details about that in my next regularly scheduled weather narrative Thursday afternoon.
Pleasant days ahead of strong wintry storm to begin Sunday
Thursday, November 21, 2024
Temperatures are in the mid-forties late this Thursday afternoon after touching fifty degrees under sunny skies earlier. We’ll see another couple of warm and pleasant days on Friday and Saturday with mostly sunny skies on Friday giving way to increasing clouds on Saturday. These clouds are ahead of a strong wintry storm that will begin affecting our area on Sunday and likely last through the middle of Thanksgiving week with colder temperatures and significant snow accumulations.
A powerful wintry storm called a bomb cyclone in the Gulf of Alaska has pummeled the Pacific Northwest with high winds and heavy precipitation. The storm earned that moniker by the low pressure in the center of the storm decreasing by over 24 millibars in 24 hours; in fact the pressure dropped from 984 millibars Tuesday morning to a regional-record-tying 942 millibars in the evening for 42 millibars in about 12 hours!
Though it occurred in the Gulf of Alaska, the 942 millibar central pressure is equivalent to a Category 4 hurricane and was fueled by an atmospheric river, which is a long, relatively narrow, concentrated plume of water vapor that transports heat and moisture out of the tropics and toward the poles. Some may be familiar with the Pineapple Express, an atmospheric river originating from around Hawaii that sometimes brings heavy precipitation to Colorado.
Pieces of the storm are forecast to break away through the weekend and into next week and move inland, with the first relatively weak wave forecast for our area on Sunday. Ahead of that, a ridge of high pressure centered over the Rockies will keep the mostly sunny skies around for Friday, with high temperatures again approaching fifty degrees, about ten degrees above our average of 39 F.
Another similarly warm day is forecast for the Opening Day at the Steamboat Ski Resort on Saturday, though expect increasing clouds through the day as the first wave from the Pacific Northwest storm approaches. There is some uncertainty regarding the timing and path of this wave, but snow showers will likely start sometime Sunday, perhaps in the morning or later in the afternoon. There could be between four and eight inches of snow at and above mid-mountain and one to four inches in town by Monday morning.
A brief break in the weather might occur on Monday, but snows should intensify on Tuesday and Wednesday as the remains of the Pacific Northwest storm move near or over our area. Significant snow is likely, along with difficult travel over Rabbit Ears Pass at times. There is some uncertainty with the track and timing of the storm, including snow amounts, so check back to my next regularly scheduled weather narrative on Sunday afternoon for the latest details.
Temperatures to warm after a very cold Tuesday
Sunday, November 17, 2024
Sunny skies and temperatures near freezing are over the Steamboat Springs area this Sunday noon. Increasing clouds on Monday will be followed by a quick-moving cold front that will bring a bit of snow and cold mid-winter temperatures for Tuesday. But the noteworthy cold will moderate starting Wednesday under sunny skies with temperatures approaching fifty degrees by the end of the workweek.
An eddy of low pressure is currently over Baja as a cold storm from the Gulf of Alaska pounds the Pacific Northwest. Quiet weather between the storms will be overhead today with sunny skies and high temperatures reaching the upper-thirties, around five degrees below our average of 42 F. The approaching storm will dislodge the eddy, though it will stay first south and then east of Colorado as it moves across Kansas on Monday and towards Minnesota by Tuesday.
Clouds will increase Monday morning as the strong cold front associated with the northwest storm approaches. Light snow showers under breezy conditions should break out after noon ahead of the cold front timed for sunset, give or take several hours, with better showers along and behind the cold front. Snow showers look to hang on during a continued breezy Tuesday in the unseasonably cold air behind the front, though due to limited moisture, total storm amounts may only be an inch or two in town and 2-5” on the hill.
High temperatures in town on Tuesday may only reach the low twenties, almost twenty degrees below average, with the record coldest high temperatures for the date being 20 F in 1929, 21 F in 1930 and 24 F in 1985. And if skies clear as expected Tuesday night, low temperatures will fall into the low single digits, even to around zero degrees in the favored low-lying spots of the Yampa Valley, well below the fifteen-degree average.
Temperatures start to recover on Wednesday as a ridge of high pressure begins to build over the West ahead of a strong storm forecast to develop in the Gulf of Alaska. Mostly sunny skies should allow temperatures to rise above average and into the mid-forties on Thursday, with even warmer temperatures approaching fifty degrees on Friday despite possible high clouds.
Similarly warm temperatures are forecast for Saturday, which is Opening Day at the Steamboat Ski Resort. There is a fair bit of uncertainty concerning how that Gulf of Alaska storm evolves, with current forecasts advertising snow for Sunday. Enjoy the sunny days before and after the mid-winterlike cold front on Tuesday, and check back for the latest Opening Weekend forecast in my next regularly scheduled weather narrative on Thursday afternoon.
