Thursday, June 27, 2019
Only several days removed from our last snowfall in Steamboat Springs on this past Sunday, I can finally talk about summer weather! A disturbance from the south will increase the chances of rainfall starting later Sunday and Monday, while a disturbance to our north will continue those increased chances on Tuesday. Drier air should be around for Wednesday and Thursday, the Fourth of July, before rainfall chances increase again as we head into the long holiday weekend, courtesy of the North American Monsoon.
A large and cold storm currently in the Pacific Northwest will split into several pieces over the next several days thanks to incoming Pacific energy and cold air moving southward from just south of the Arctic Circle. The storm will undergo a complicated evolution, but our area will be spared most of the forecast uncertainty as a sprawling ridge of high pressure encompassing much of the U.S. shunts most of the storm to our north. Unlike last week, this is representative of average summer weather.
Ahead of the storm, we should see mostly sunny and dry weather with breezy southwest winds for the rest of today and Friday. On Saturday, the remnants of Alvin, the first subtropical storm of the season that originated off the western coast of Mexico, will travel along the western periphery of the ridge of high pressure and increase moisture over our area.
There may be some chance of showers Saturday afternoon and evening as the remnants of Alvin approach, but much better chances emerge on Sunday and Monday as the subtropical disturbance passes overhead.
Winds will decrease and swing to be more from the west on Monday and northwest on Tuesday as a piece of the old Pacific Northwest storm mixes with the cold air originally from the Arctic Circle and treks across the Canadian Plains. A weak cool front is forecast to move across our area later Tuesday or early Wednesday, and good shower chances will continue ahead of and along the front.
Drier air moves in from the west behind the front on Wednesday and Thursday, Independence Day, before moisture is again forecast to increase heading into the holiday weekend, this time from the south as the North American Monsoon develops. After three major snowstorms that contained inch per hour snowfall rates at the higher elevations for about twenty hours or so around May 22, May 29 and June 21, it appears the atmosphere is returning to some sort of normalcy with the on-time arrival of the monsoon.
Sunday, June 23, 2019
Our third summer day in Steamboat Springs this Sunday morning brought another inch of snow on my deck near the base of the ski area and 8” of snow overnight near the top of Mt. Werner. The three day storm is finally winding down, with some peaks of sun already visible in the Yampa Valley. We’ll go from winter this morning to spring on Monday and summer on Tuesday, with the summer weather finally looking like it will hang around for, well, the summer.
There is a lot to talk about with this past storm, as between Thursday night and Sunday morning, it put down around 30” of snow at the top of the Steamboat Ski Resort, along with significant accumulations down to 8500′ and lesser amounts down to the valley floor.
The liquid water equivalents are equally eye-popping, with around 3” reported at the Tower SNOTEL near the top of Buffalo Pass and at the Rabbit Ears Pass SNOTEL, and around 2.5” - 3” reported by CoCoRaHS in the valley, depending on the location. For reference, our average June precipitation in Steamboat Springs is 1.7”, which we had before this storm started! And this after a May with almost twice our average precipitation and a daily temperature 3.7 F below average.
And along with the notable precipitation from this storm was the cold, with the high temperature on Friday of 50 F occurring at midnight, with steadily falling temperatures for most of the day before a high of 39 F was reached at 8 pm. That’s 37 degrees below our average of 76 F on the first day of summer, and was a large enough departure so this one day lowered our average June daily temperature by almost a half degree!
My forecast from Thursday turned out woefully conservative, even though at the time it seemed very aggressive for the first day of summer. The storm was colder, with snowflakes reported in Hayden, and more intense than advertised by all weather forecast models. The Colorado Avalanche Information Center (CAIC) model did come close to the amounts, though with the model running four times per day, only the simulation that started midnight on Thursday as the storm started hinted at such large totals.
As an aside, after talking with Science and Operations Office over at NWS Forecast Office in Grand Junction this morning, it turns out that their balloon-based atmospheric sampling instrument had been down for this storm, and that likely contributed to the under-predictions of the weather forecast models as the center of the storm was poorly sampled.
But really, this is the third storm since the two that ended on 22 May and 29 May that brought around a 20 hour period of snowfall with rates around an inch per hour and snow down to the valley floor. And the cherry on top of the storm last night was the additional 8” of snow that fell by this mid-morning. Snowfall rates this high for this long are unusual even in the heart of winter.
I’m interested in hearing long-time locals thoughts about these past three storms, especially the ranchers and farmers who are keen observers of the weather. Just click the add a comment link below so all can read, and be sure to include any historical context that occurs to you.
So a far more benign forecast is on our plate for the upcoming week. We should see periods of sun this afternoon, interspersed with showers as the very moist surface is heated and interacts with the cold and unstable northwest flow aloft.
Monday will feature plenty of sun as the winds turn from the northwest to the west, with high temperatures approaching, but staying below our 76 F average. There will also be a chance of afternoon and early evening storms, most likely tied to the higher terrain.
By Tuesday, another large and cold storm will drop down the Pacific Northwest coast, forcing a ridge of high pressure to build over the Rockies and bringing much drier southwest flow over our region. High temperatures will finally be around average with only a small chance of afternoon showers.
Further warming and drying is expected for Wednesday and the first part of Thursday as the ridge of high pressure over our area builds further north, and keeps the Pacific Northwest storm at bay. But after only a few days removed from snow, the North American Monsoon may get started as a ridge of high pressure over Florida bulges to the northwest and draws moisture northward along the clockwise flow on its western side. A weak plume of moisture may extend up into eastern Colorado by later Thursday, and it may or may not be far enough west to bring the chance of afternoon showers to our area.
Coincidentally, more incoming Pacific energy dislodges the Pacific Northwest storm eastward by the end of the work week, but the ridge of high pressure over our area will finally have enough strength to deflect the storm to our northwest. It does appear that the ridge will be temporarily deformed enough to push whatever monsoonal moisture plume that may be over our area to the east, leading to a warm and dry start to next weekend.
Thursday, June 20, 2019
Enjoy the sunny and warm weather we are currently experiencing early this Thursday afternoon in Steamboat Springs since a cold front is barreling down from Wyoming. A rude welcome to the summer season is on tap for tomorrow, the first day of summer, when the Summer Solstice occurs Friday at 9:54 am MDT. Much colder temperatures along with rain in the Yampa Valley and snow at the higher elevations will occur tomorrow and through the weekend before more summery weather returns for the beginning of the workweek.
The inclement weather is courtesy of an unseasonably cold storm currently in Idaho that will move across Montana on Friday and head north into the Canadian Plains on Saturday. A couple of waves of energy and moisture spinning around the storm will drag two cold fronts through our region, with the first one timed for later this afternoon and the second for later Saturday.
Winds have already increased ahead of the first cold front, with showers expected ahead, along and behind the front. As the storm to our north moves slowly eastward, the cold front stalls over northern Colorado for a couple of days, becoming a stationary front and bringing steadier rain overnight and through tomorrow, with several inches of accumulating snow expected above 10,000′, snowflakes down to 9000′ and high temperatures twenty to thirty degrees below our average of 75 F! Follow any snowfall on the Powdercam at the top of Sunshine Peak or at the Four Points cam.
Another lobe of energy rounds the storm during the day Saturday and drags a second cold front through our region Saturday afternoon or evening. Precipitation may become lighter and more showery, with peaks of sun, early in the day as the southwesterly flow ahead of the secondary cold front pushes the stationary front northward, but showers will increase again ahead, along and behind the second cold front. Localized moderate to heavy precipitation, even lower snow levels, gusty winds and small hail may make travel difficult, especially at pass level, during the afternoon and evening.
Precipitation will likely end for a time later Saturday night into Sunday morning as the storm moves east of our area, but showers will redevelop during the day Sunday and extend into the evening in the cold, moist and unstable northwest flow behind the front.
Winds will turn to the west on Monday and then southwest as another strong Gulf of Alaska storm moves toward the Pacific Northwest early in the workweek. While this storm will also be unseasonably cold, summer looks to win this battle and keep the storm away from our area as a ridge of high pressure builds over the west. Very dry air and temperatures recovering to near average on Monday and then eventually above average are forecast for the remainder of the workweek and heading into the following weekend.
Even as the springlike storm passes by this weekend, there are signs of the North American Monsoon starting as moisture from Mexico is pulled northward around the building ridge of high pressure over most of the U.S. At this point, the moisture is not expected to make it further north than central New Mexico during the week, but it’s interesting and unusual that I am discussing air masses from near the North Pole and the Equator in the same weather narrative.
Sunday, June 16, 2019
The unsettled weather Steamboat Springs has seen for the last several days will continue through Tuesday before drying occurs for Wednesday and some of Thursday. The unsettled weather looks to return later Thursday and extend into next weekend as another storm moves across the West.
First, thanks to those who commented on possible changes to this twice weekly forecast, and those who have not commented can still do so by following the link above or just clicking here. I had wanted to try and take this Sunday off, but lots happening as we approach the Summer Solstice on Friday at 9:54 am MDT.
Our weather currently is influenced by a couple of stormy areas to our north and southwest. Waves of energy and moisture rotating around the storm to our north and ejecting out of the storm to our southwest will conspire to bring good chances for showers and storms to our area for the next three days, with the best chances and greatest coverage on Monday and Tuesday. Like on this past Friday, the storms will be capable of localized moderate to heavy rain, gusty winds and small hail.
Meanwhile, a strong storm crossing the Gulf of Alaska will mix with some still-cold air from near the North Pole as it crosses the Pacific Northwest coast around Tuesday. Winds will increase as they turn from the northwest to the west on Wednesday, briefly bringing dry air overhead and likely eliminating any precipitation potential.
Additional Pacific energy will move into the storm early on Thursday, further increasing the winds as they turn from the west to the southwest. Also, there will be enough cold air associated with the storm to form a mostly stationary cool front extending from roughly central Utah through northern Colorado.
Another round of unsettled weather looks to start around later Thursday as the stationary front forms near our area. But this will be a tricky forecast as drier air lurks just to the south of the front, creating a relatively sharp boundary between the warm and dry or cool and showery weather.
I expect the forecast to change, but right now, Friday looks to be the most active day for our area, with that activity possibly extending into at least part of Saturday. More Pacific energy follows, and though weather forecast models disagree on the evolution of those disturbances, the current forecast bring warmer and drier weather back to our region later in the weekend.
Thursday, June 13, 2019
The past few days of beautiful mostly sunny weather in Steamboat Springs will be turning more unsettled for the upcoming week. Waves of Pacific energy and moisture will move over the West and increase rainfall chances starting on Friday and lasting through midweek.
Though our area has enjoyed mostly sunny skies with high temperatures right near our average of 73 F over the last few days, atmospheric moisture this Thursday is already increasing ahead of several Pacific disturbances taking aim on the West. The first will bring some more clouds this afternoon, and any showers will be confined to the higher elevations to our north and produce more wind than rain as the lower levels of the atmosphere are quite dry.
But that changes on Friday as a stronger disturbance passes by in the afternoon and substantially increases the moisture in all levels of the atmosphere. Showers will become more likely by later in the day and overnight, some of which may produce brief periods of locally moderate to heavy rain.
Another disturbance is forecast for later Saturday, so more showers producing locally moderate to heavy rain for a time are again likely. In fact, a parade of nebulous and hard-to-time disturbances will pass by in generally west to northwest flow through Tuesday of next week, keeping good chances of mostly afternoon and evening showers, some moderate to heavy, on each day.
By mid-next week, a series of stronger Pacific disturbances are forecast to cross the Pacific Northwest coast. There is weather forecast disagreement with regards to the southern extent of these disturbances, but models agree that we will at least see breezy to windy west to northwest winds as these disturbances move eastward.
Lastly, I am considering decreasing the frequency of these weather narratives to once per week on Thursdays in order to lessen my workload. And I’m just not sure how many people are reading this in the summer. Please contact me if you have thoughts about this possible change.