Last round of precipitation to come later today
Sunday, October 20, 2024
After an extended period of low clouds and fog, the sun is out this Sunday noon in Steamboat Springs with temperatures around fifty degrees, headed toward the low sixties. But a wintry storm bringing significant snow to southwestern Colorado, including the first snowfall of the season of two inches at the Steamboat Ski Resort Friday morning, is not done with us yet. Low-elevation rain showers and high-elevation snow showers will redevelop around sunset and last through the night before skies grudgingly clear Monday ahead of a warm and dry workweek.
An eddy of low pressure is over the Four Corners and is forecast to move across central Colorado today before reaching the corner of northeastern Colorado on Monday. Ahead of the storm center, our area saw good precipitation, with thunderstorms leaving around a half-inch of rain in town late in the day on both Thursday and Friday, with the first snowfall of the season at the Steamboat Ski Resort showing two inches at mid-mountain by first thing Friday morning.
As expected in my last weather narrative on Thursday, easterly winds aloft wrapping around the low pressure eddy squashed any precipitation chances on Saturday. Unusually, town was left with a thick stratus deck invading from the north, associated with the low-level cold front from the northern part of the storm, that lasted much of the day as shown in the first animation. 
It starts at 5:20 am on Saturday, October 2024 and extends until 9:40 am after which it briefly pauses. Not much changed until 4 pm when the animation resumes and lasts until sunset showing the stratus layer quickly eroding. This was a very interesting meteorological phenomenon, and was likely due the easterly winds aloft bouncing along the top of the stratus deck through most of the day thanks to the stable atmosphere in the presence of a temperature inversion; temperatures in town did not rise above forty degrees until noon while it was above that up top by 9 am. There was plenty of dry air aloft thanks to the easterly winds downsloping off the Park Range, with relative humidities reaching as low as 25% by the afternoon. Finally, when town approached its high temperature of the day of 52 F, this dry air was mixed into the moist layer below and the stratus deck quickly eroded, with relative humidities in town only falling to 67%.
We were greeted by another stratus layer this morning, though when the cloud is on the ground it is called fog, this time invading from the south as cool air drained down the South Valley, as shown by the second animation. It starts at 5:20 am and lasts through 11:20 am, and shows a more normal evolution of the fog layer due to the warming temperatures causing the fog to evaporate. The low elevation of the fog is apparent as Emeral Mountain stays visible in the background the entire morning, unlike yesterday when the stratus layer engulfed the mountain.
So we are left with a mostly sunny Sunday afternoon, but that won’t last as the eddy to our south begins to affect our area with more low-elevation rain showers and high-elevation snow showers that should begin around sunset. Winds from the south will eventually turn to be from our favorable northwest direction after midnight as the storm moves eastward, forcing air to rise as it encounters the Park Range and continuing the showers into the early morning, with 2-5” expected on the hill. Though there is not a lot of cold air associated with the storm, there may be enough to see some snowflakes in town by Monday morning.
Clouds will grudgingly depart by Monday afternoon, leaving high temperatures a degree or two below our average of 57 F. But locals know clearing skies behind a storm usually means a cold morning follows, and we could see the first hard freeze in the Yampa Valley on Tuesday morning, with temperatures falling to within several degrees of our average low of 25 F.
A flat ridge of high pressure is forecast to build over the West behind the storm, bringing sunny skies and warming temperatures five to ten degrees above average through the workweek. The pleasant weather may last through next weekend, and I’ll have more details about that in my next regularly scheduled weather narrative on Thursday afternoon.
Wintry storm to affect our weather on both sides of the weekend
Thursday, October 17, 2024
Temperatures in Steamboat Springs are in the upper-fifties late this Thursday afternoon under cloudy skies. A large and complicated wintry storm will bring two rounds of low-elevation rain and high-elevation snow to our area; the first as the storm approaches the Four Corners tonight through Friday and the second from Sunday afternoon through the night as the storm departs Colorado.
A strong and splitting storm currently over Nevada is forecast to first move into Arizona on Friday and form an eddy, then drift to the Four Corners by Sunday morning before quickly moving to the northeast across Colorado through the rest of the day. A cold front associated with the northern part of the splitting storm is on our doorstep, and combined with the moist flow from the south ahead of the soon-to-be eddy, we should see an active night of high-elevation snow showers and low-elevation rain showers.
We could see 1-4” of snow above 9000′ or so by Friday morning, and I’ve placed the latest two-hour movies of the Steamboat Powdercam and the Steamboat Mid-mountain Powdercam on the SnowAlarm home page so we can view the first snow of the season. If the images I download every twenty minutes are not available, the live-view videos can be accessed at the Steamboat Powdercam live view and the Steamboat Mid-mountain Powdercam live view.
The eddy will be strong enough to ingest some dry air from its southwest flank over Baja and create a lull in precipitation before noon on Friday. But afternoon and early evening showers will emerge again with another inch or two of snowfall possible above 9000′ by Saturday morning.
By then, the eddy will be over central Arizona, and while heavy precipitation is expected in southwest Colorado, our area will see gusty winds from the east as winds rotate counter-clockwise around the eddy. Easterly winds usually doom our precipitation chances due to downsloping off the Park Range, which results in drying and warming, so we should see a break in the precipitation lasting from early Saturday through Sunday morning.
By Sunday afternoon, the eddy is forecast to be over central Colorado, and we should see another round of precipitation begin as winds turn to be from our favorable northwest direction. More low-elevation rain showers and high-elevation snow showers should continue through Sunday night, leaving another 2-5” of snowfall near the top of the Steamboat Ski Resort.
Earlier forecasts had a colder event, but the splitting nature of the storm will keep the coldest air to our north. High temperatures in town will range from the high fifties to the low sixties through the weekend, right around our average of 58 F, with Saturday being the warmest day.
Mostly sunny skies should return on Monday, with temperatures again near average, before above-average temperatures return for the rest of the workweek. I’ll review the first part of the storm and have more details on the second half of the storm in my next regularly scheduled weather narrative on Sunday afternoon.
Warm and dry conditions continue to start the workweek
Sunday, October 13, 2024
Skies have turned sunny this Sunday noon in Steamboat Springs with temperatures in the low-sixties, again on their way to the low-seventies. The warm temperatures will continue through midweek with passing afternoon clouds most likely today and Monday before better moisture arrives Wednesday afternoon along with increasing winds and chances for showers. A strong winterlike storm will then approach our area after midweek with its track and timing still very uncertain.
An eddy of low pressure over Nevada is trapped underneath a ridge of high pressure extending over much of the West as a large and powerful storm evolves between the Dateline and the Gulf of Alaska. Moisture drawn northward ahead of the eddy may lead to some passing clouds through Monday, especially during the afternoons, but precipitation chances are near nil thanks to the stable atmosphere under the ridge and the dry lower atmosphere.
High temperatures through Wednesday will stay in the low-seventies, almost fifteen degrees above our average of sixty degrees as the Nevada eddy drifts into Arizona. But big changes are coming as the strong Gulf of Alaska storm crosses the Pacific Northwest coast on Wednesday. The Arizona eddy will be forced to the northeast and over our area later Wednesday, leading to thicker afternoon clouds bearing shower chances and increasing winds from the southwest.
Winds will increase further on a still-cloudy Thursday as the incoming storm moves into the Great Basin. At this point, there is still major disagreement between the weather forecast models, with the American GFS insistent that the storm will split early Friday and the European ECMWF just as insistent the storm will move across our area. The guidance highlights this uncertainty with high temperatures on Friday ranging between 41 F and 65 F in town and between 26 F and 45 F near the top of the Steamboat Ski Area!
Some sort of compromise solution usually reconciles such a large disagreement in potential outcomes, but in either case the cold air and at least some moisture eventually moves through the area, perhaps by Friday or perhaps later during the weekend, or both. Significant snow is possible at the higher elevations, with even accumulating snow advertised in town in some of the solutions.
So enjoy what seems like the endless mild fall weather more representative of mid-September than mid-October to start the workweek, and check back for what should be a very interesting weather narrative on Thursday afternoon for more details on this potential winterlike storm.
Seventy degree temperatures to last through the weekend
Thursday, October 10, 2024
Temperatures reached seventy-six degrees this Thursday mid-afternoon in Steamboat Springs under mostly sunny skies. This weekend, we will see continued warm temperatures more representative of early September than mid-October, along with periodic smoke from the Lake Fire in the Unitas. The mostly sunny skies may be interrupted by clouds early Friday and again later Sunday as a small storm approaches.
A stubborn ridge of high pressure responsible for our gorgeous fall weather still extends from the Mississippi to the West Coast. High clouds behind a storm moving across the Canadian Plains may move overhead tonight through Friday morning, but mostly sunny skies should return by Friday afternoon.
There may be a couple of pulses of smoke over our area early Friday and again Friday night, as shown by the NOAA Smoke Plume model. This model is run four times a day through 48 hours, so be sure to check that guidance for the latest forecast.
A storm now moving through the Gulf of Alaska is forecast to split, with the southern end forming an eddy that crosses the Oregon-California coast on Saturday. The eddy then begins to meander around the Great Basin by Sunday, and we may see some moisture drawn northward by the southerly winds ahead of the eddy. Clouds should increase by Sunday afternoon with even a shower possible later in the day or evening, though that would likely produce more wind than rain due to the dry lower atmosphere.
The eddy is forecast to move very little through the beginning of the workweek, and we may see some clouds and low shower chances again on Monday. The eddy is forecast to eventually be ejected to our northeast around midweek by another colder and wetter storm currently developing over the Aleutian Islands.
But we’ve already seen several storms that looked promising a week in advance fizzle by the time they approached our area, so enjoy another beautiful weekend and check back to my next regularly scheduled weather narrative on Sunday afternoon for the latest details on the next evolving storm.
Record breaking September in the books
Sunday, October 6, 2024
Sunny but hazy skies and temperatures approaching sixty degrees, again on their way to the low seventies, are over the Steamboat Springs area this Sunday noon. Smoke from the Lake Fire in the Unitas will come and go during the workweek as high temperatures hover in the low to mid-seventies, along with occasional clouds as Pacific moisture sneaks into the area. The benign weather will allow more space in this weather narrative to list some of the Steamboat Springs temperature records broken in September.
The temperature records are due to a stubborn ridge of high pressure established in mid-September that is still centered over the West. Not only were several high temperature records set in September, but we just had another one this last Friday as the 81 F recorded at the official weather station behind the high school broke the old record of 80 F set in 1945.
The highlight of September occurred around last weekend of the month when the high temperature reached 86 F on Friday, surpassing the old record of 83 F set in 2001. And the 85 F records set on both Saturday and Sunday broke the previous 83 F records set in 2010 on Saturday and 2019 on Sunday.
Combined with the unseasonably warm temperatures preceding and following that weekend, the last week of September was the hottest measured since record-keeping began in Steamboat Springs in February of 1893. These seven days broke three records and tied two, averaging a high temperature of 82.9 F compared to the old record of 81.7 recorded in 2001. The ten days straddling the start of October between September 26 and October 5 averaged a high temperature of 81.9, which also broke the previous record of 79.3 set in 1897.
Though we had some cool days, including a high temperature of only 61 F on Tuesday, September 17, the average high temperature of September was the ninth hottest on record, with an average of 78.4 F, well short of the 82.1 F set in 1897. In fact the three hottest Septembers were in 1897, 1896 and 1893. Imagine moving here as a settler in the early 1890’s and experiencing the three hottest Septembers in the next 130 years, and counting! Trying to plan for the future years based only on that short-term experience could have proven fatal.
If the average daily temperature is considered, which averages both the high and low temperature of the day, September moves up the list as the fourth warmest on record at 58.1 F, compared to the record of 58.9 set in 1998.
The temperature records look to be safe this week as high temperatures are forecast to be in the mid-seventies, especially the 89 F record set on October 9, 1910! That was also the hottest temperature recorded in October, followed by the next hottest of 84 F set two days earlier on October 7, 1910 and tying the high temperature set two years earlier on October 8, 1908. And 1908 had some warm days, as the highest September temperature of 93 F was set on September 7.
While the mid-seventies sounds cool relative to the high-temperature records, it is still around ten degrees above our average of 64 F. Some Pacific moisture may sneak under the dominant western ridge of high pressure for some occasional clouds, but smoke from the Lake Fire burning in northeast Utah may prove to be the most noticeable element of the workweek weather. Check the NOAA Smoke Plume model, also available via the See the latest NOAA smoke model forecast link under the Purple Air widget on the SnowAlarm home page for the latest smoke forecast. The model is run four times a day through forty-eight hours, and currently predicts some smoke abatement on Monday before another pulse approaches our area on Tuesday.
There was earlier hope of a storm around next weekend, but the weather forecast models have backed off that prediction for now. So enjoy another warm fall workweek, and check back for the latest details on the coming weekend weather in my next regularly scheduled weather narrative on Thursday afternoon.
