Sunday, July 7, 2019
The sunny skies this Sunday morning in Steamboat Springs have given way to increasing clouds as moisture moves over our area in southwest flow. Showers will be possible later today and again tomorrow before drying occurs on Tuesday. The dry air will stick around through the workweek along with our warmest temperatures of the summer so far, before moisture returns around the weekend.
Currently, we are seeing increased moisture in the southwest flow ahead of a cold storm near Vancouver. There will be a chance of afternoon and evening showers today and again Monday before the Vancouver storm travels across Montana on Tuesday and drags a weak cool front through our area. The air will cool and dry as we see breezy westerly winds, keeping high temperatures on Tuesday comfortably below our average of 81 F.
But as the storm travels eastward across the northern U.S. border through the workweek, a ridge of high pressure will build over the Rocky Mountains starting on Wednesday. Temperatures will be the warmest of the summer so far, with high temperatures around five degrees or so above average and almost no chance of rain through Thursday.
By Friday, additional incoming Pacific energy flattens the ridge of high pressure over the Rockies, and this is important for our area as subtle changes in the position and strength of the ridge influence the fetch of moisture from the south associated with the North American Monsoon. But these subtle differences make for a tough forecast as relatively minor changes in the upper level flow may mean the difference between a wet and dry prediction.
With that said, shower chances are currently advertised to return around Friday. Though a ribbon of dry air is forecast to be just to our north through the following weekend, if that stays to our north as currently forecast by some weather prediction models, then the chance for showers will continue through the weekend and into the following workweek.
Thursday, July 4, 2019
The Steamboat Springs area is currently experiencing a beautiful warm, dry and sunny Independence Day. More of the same is expected through most of the long Fourth of July weekend before precipitation chances increase for later Sunday and Monday. The chances decrease for a couple of days before increasing again toward the end of the workweek and heading into the following weekend.
Counterclockwise flow around a strong and cold storm centered near Vancouver has brought warm and dry southwest flow to our area. While cold air from western Canada and additional incoming Pacific energy will periodically energize the storm over the next few days, a ridge of high pressure building northwestward from the Louisiana coast into Texas and the Rocky Mountains will keep any weather associated with the storm at bay. So the warm and dry days and cool nights will continue through the first half of the weekend.
By later Sunday, clockwise flow around the Texas ridge of high pressure will carry some moisture from the Mexican Plateau northward as the light winds turn to be more from the south. This pattern is representative of the beginnings of the North American Monsoon, and there will be increasing chances for showers from later Sunday through Monday.
Meanwhile, part of the Vancouver storm will move eastward across the northern Rockies early in the workweek and suppresses the Texas ridge of high pressure southward. Drier air will return for Tuesday and Wednesday as the winds turn back to southwesterly or even westerly.
The old Vancouver storm is then forecast to travel east of the northern Rocky Mountains around midweek, allowing the Texas ridge to rebuild to the west and northwest. The strong summer sun will allow the ridge of high pressure to prevail over any storminess to our northwest, and the North American monsoon looks to become better established over mostly New Mexico and Colorado. The forecast moisture over our area will increase precipitation chances for the end of the work week and the following weekend, with a stronger and wetter monsoon signature forecast by some weather forecast models for the following workweek.
Sunday, June 30, 2019
A seasonably warm and sunny Sunday morning in Steamboat Springs will give way to the chance of afternoon and evening showers today through Tuesday. Drier air moves in midweek in time for Independence Day on Thursday and will stick around through the long holiday weekend.
Southwest flow ahead of a disturbance off the Pacific Northwest coast has allowed the remnants of former hurricane Alvin to move across the Desert Southwest yesterday and towards our area today. We should see a good chance of afternoon and evening showers as the once-tropical disturbance moves just to our northwest today.
Meanwhile, more incoming Pacific energy and cold air from western Canada will continue to mix with the Pacific Northwest disturbance, keeping it spinning off the coast early in the work week. Combined with a ridge of high pressure building northwestward from the south-central U.S., our area will see relatively moist southwesterly to southerly flow that will keep the threat of afternoon and evening storms going on Monday and Tuesday, with Monday likely the driest of the three day period.
The Pacific Northwest disturbance is then forecast to move eastward midweek, and our winds will turn to be more from the west as the air mass dries. Several weak cool fronts will be on our doorstep during the second half of the workweek, but summer will win this the battle and keep most of the cool air and almost all of the precipitation to our north. So mostly sunny skies and seasonable temperatures around or up to five or so degrees above our average of 79 F are expected starting Wednesday and continuing into the long Fourth of July holiday weekend.
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.