Monday, October 2, 2017
The strong winter-like storm that is still gripping the Steamboat Springs area has left 19” of snow containing about 2.4” of liquid water at the top of Sunshine Peak near Patrol Headquarters, as shown by the current Steamboat Powdercam, and about 6” on my deck near the base of Mt. Werner. In the Yampa Valley, the rain that started around 2:30 Saturday afternoon left about an inch of water by Sunday morning. By mid-morning Sunday, the rain had changed to snow, certainly much earlier than my Thursday forecast, and continued through Monday morning, leaving about another inch of liquid water in the valley.
The cold air associated with this storm, sourced from the North Pole, was not to be slowed by the southwest flow aloft, and snow levels dropped faster and further than originally forecast. Snow showers will taper off through the afternoon today, with another weak round of showers possible around midnight.
Some drier air should move over our area after midnight, and if skies clear, temperatures will fall to the lowest levels of the season so far. Below normal temperatures will persist into Wednesday as the sun’s energy goes into melting the snow rather than warming the atmosphere.
As this storm lifts to our northeast by midweek, another storm moving southward from British Columbia briefly stalls in Nevada through midweek. This will keep southwest flow over our area until the end of the work week and we will see warming temperatures under continued mostly sunny skies.
As energy traveling across the Pacific crosses the British Columbia coast around Friday and energizes the jet stream, the Nevada storm is ejected to the east and northeast, moving over or near our area sometime on Friday. This storm will be quite dry, likely with no precipitation, but it should knock temperatures back a bit for Friday.
Uncertainty emerges for the weekend as it is not clear how strong and how far south the Pacific jet stream will travel as it sags southward across the Intermountain West after crossing the West Coast. Earlier forecasts had significant warming and drying over Colorado for the weekend, but current numerical model forecasts now have the jet stream pushing further south, and this will likely limit the previously advertised warming and drying as cooler air and clouds lurk to our north.
Thursday, September 28, 2017
This forecast sounds like a broken record, but several more storms will impact the Steamboat Springs area through at least early next week, with a possible break around midweek.
Currently, a compact storm in central Utah has brought a round of precipitation to the Yampa Valley earlier today as waves of energy and moisture from the south rotated through our area. Though moisture decreases, there will still be a chance of showers later today before ending in the evening.
Friday will be another unsettled day as the storm in central Utah lifts to the northeast and clips northwestern Colorado, with showers starting as soon as noon.
We will have a brief break in the weather Friday night and Saturday behind the departing storm and in advance of another stronger and much colder storm from the Pacific Northwest that is forecast to arrive later Saturday or early Sunday.
This storm has mixed with some cold air from the North Pole and will bring a series of cold fronts through the region. Showers will become numerous and increase in strength later Saturday and last through the night as the first cold front approaches. Much cooler temperatures and continued showery weather is expected for Sunday as snow levels fall to around 8000 - 9000 feet.
As is often the case with these large storms, reinforcing waves of cold air will follow behind the initial front. Numerical weather models had this cold air washing directly over northern Colorado in my Monday forecast, but now the cold air is forecast to elongate the storm to the southwest, keeping the coldest air to our north and west as southwest flow develops over Colorado. Cool and showery weather is expected for Monday, with snowflakes still possible down to the valley floor, though models have trended this weather further north in recent runs, reducing the confidence in that forecast.
There will be a battle between the cool air to our northwest and warmer air to our southwest, and numerical weather models now have the cold front retreating northward by Tuesday as the warmer air briefly wins the battle. This retreat will create the break in the cool and showery weather for Tuesday and Wednesday before remnants of the storm move eastward over our area later in the work week. Details will have to wait until there is better model agreement as to exactly how that might happen.
Monday, September 25, 2017
As one center of circulation currently located in Wyoming moves to the northeast, another wave of energy moving southward from British Columbia forms another circulation center in southern Nevada by Wednesday that is cutoff from the jet stream. The cool and unstable northwest flow behind the departing Wyoming storm will continue the chance of afternoon showers today before cool and mostly sunny fall weather graces the Steamboat Springs area for Tuesday.
By later Wednesday, we will begin feeling the effects form the cutoff low which is forecast to move northeastward through the Great Basin as temperatures warm towards normal. Moisture from the south will be pulled northward by the southerly winds on the eastern periphery of the circulation, and the moisture may make it far enough north to produce a chance of light showers in our area by late in the day Wednesday.
Interestingly, on Wednesday, the old Wyoming low is absorbed by fast westerly flow along the Canadian border, and along with continued energy moving southward from Hudson Bay, will help deflect hurricane Maria to the northeast as the jet stream moves eastward across the Great Lakes, sparing the central East Coast form a direct hit.
By Thursday, the Great Basin low is forecast to in central Utah, and waves of energy rotating around the low will combine with increasing moisture from the south to produce increasing chances of showers, with high snow levels, for Thursday and Friday.
Recent model solutions have done away with the ridge of high pressure that was originally forecast for the weekend in favor of some sort of cool trough of low pressure from the Pacific, reinforced with some cold air from the North Pole. And if your thinking that sounds cold, then you are right. Current forecasts, which will almost certainly modify this week due to the recent large forecast model changes, indicate that while we have a chance of showers later Saturday ahead of the front in near normal temperatures, much colder air will arrive sometime on Sunday with showers and lowering snow levels.
While we may not see our first snow in the Yampa Valley then, a reinforcing wave from the northern latitudes crosses the Pacific Northwest coast later Sunday. There is disagreement among the models, with the ECMWF holding the coldest air to our west and north and the American GFS bringing a more consolidated push. The colder solution would bring another round of showers around Monday afternoon, with some snowflakes possible in the city.
Thursday, September 21, 2017
An anomalously large trough of low pressure stretching from the central Canadian plains southwestward to almost Baja will affect our weather over the next week. Ahead of the trough, strong southwesterly flow has brought above average temperatures, sunny skies and wind to the Steamboat Springs area today.
There will be many moving pieces to the forecast as upstream Pacific energy contributes to several centers of circulation forming within the trough, with some of them being reabsorbed as they travel to the northeast, while others further stretch the trough to the southwest while reluctantly moving it eastward toward the Rockies.
Temperatures should stay warm through tomorrow morning ahead of gradually cooling temperatures through the weekend and into next week. The very slow movement of the trough will preclude any distinct cold front, but the slow cooling of the atmosphere combined with waves of energy moving over our area will contribute to an extended period of cool and showery weather.
There may be some showers Friday, though the heavier and more persistent precipitation will wait until Saturday and Saturday night when the trough is closer to our area and ejecting pieces of energy travel over Colorado.
There may be some dry air that mixes with the trough, possibly allowing for a break in the unsettled weather for a time on Sunday, before an unconsolidated center of circulation moves northeastward across Colorado later Sunday and Monday and brings another push of cooler air and storms.
Additional upstream Pacific energy crossing the West Coast regenerates the southern end of the trough early in the week, and though the coolest temperatures of the storm will occur over our area then, precipitation looks to become much lighter as the week progresses.
Right now, numerical models have the last push of cool air occurring around the end of the work week, and this finally moves the storm complex east of our area. A ridge of high pressure is advertised to bring much warmer and drier conditions for the following weekend.
Monday, September 18, 2017
Temporally sandwiched between hurricane Jose, currently threatening the New England Coast, and hurricane Maria, which may threaten a broader portion of the East Coast next week, a large and potent storm from the Gulf Of Alaska is currently crossing the Pacific Northwest coast.
After a relatively warm and dry Monday in the Steamboat Springs area, conditions will become breezy to windy from the west and southwest on Tuesday as the fairly dry first part of the splitting storm moves north of our area tomorrow afternoon or evening. Precipitation now looks to reach only as far south as the Wyoming border, so cooler temperatures with continued dry and breezy conditions are expected on Wednesday.
Several additional waves of energy will move through the storm, creating a complicated forecast that will likely evolve as we move toward the weekend. Right now, the first of these waves for midweek looks to largely keep the storm to our northwest, perhaps pulling in some drier and warmer air over Colorado for Thursday.
By Friday, another wave traveling around the storm to our northwest gets close enough to our area to increase the chance of storms for later in the day.
On Saturday and continuing into early next week, additional waves of energy move the storm to the east while elongating the storm to the southwest, which is forecast to bring several days of cool and showery conditions to the Yampa Valley with some snows at the higher elevations.