Monday, October 31, 2016
While one weather system leaves the area tonight, another one that is currently crossing the northern California coast will split tomorrow as it enters the Great Basin. The weaker northern part of the storm races eastward and brings the possibility of light showers to our area as early as noon Tuesday that may persist into Wednesday morning with similar temperatures to today.
Meanwhile, the dominant southern portion of the split forms a closed low by Wednesday as it sinks into Arizona. The track and evolution of these cutoff lows are notoriously difficult to forecast which leads to some uncertainty for the rest of the week’s weather. Current forecasts agree that the bulk of the warm moisture and precipitation will be to our south, with northern Colorado sandwiched between dry air to our north and the wobbly cutoff somewhere to our south and west.
The end result is Wednesday will show clearing skies and the dry air to our north will likely move over our area for Thursday and Friday with noticeably warmer temperatures.
After meandering for a few days in the Great Basin, models have the cutoff low weakening and moving eastward across Colorado during the weekend. While warm precipitation is a good bet for southern Colorado, small changes in the actual track will be the difference between thin weekend clouds for a nice Steamboat Springs weekend, thicker clouds for a cooler weekend or even a showery weekend if the low moves far enough north.
Even more uncertainty is advertised for early in the next work week behind what is left of the departing closed low. The American GFS brings a strong trough with colder temperatures and good moisture through our area on Monday while the European ECMWF brings a much weaker and drier trough through or even north of our area around then.
Thursday, October 27, 2016
A Pacific Northwest storm is being forced southward and eastward by energy dropping southward from the Aleutians. Though the last forecast had the storm splitting as it crossed the California coast, current forecasts keep the storm more consolidated as it moves across the Great Basin during the weekend.
Ahead of this storm, the tropical system mentioned in the earlier forecast had turned into a hurricane named Seymour, and the remnants will move through the Great Basin on Saturday ahead of the Pacific storm. Though this will mix with some cool air from Canada, the bulk of the storm looks to graze the Steamboat Springs area late Friday and early Saturday, with some cooler temperatures closer to average and light rain showers as it is deflected to our north by the still dominant western ridge.
We should be between waves later Saturday into Sunday morning before the aforementioned Great Basin storm again brings the chance for showers later Sunday and Monday with breezy southwest winds, cooler temperatures and snow levels between 8000′ and 9000′.
Weather looks to clear again for Tuesday and Wednesday with average temperatures, but there is a lot of uncertainty with regards to the Aleutian energy that eventually makes landfall early in the work week. Originally, models had the storm affecting our area around Thursday but now at least the ECMWF model is forecasting a closed low that may end up staying south of our area.
Monday, October 24, 2016
Southwest flow ahead of a large storm currently spinning off the Pacific Northwest coast will carry some tropical and subtropical moisture through the Steamboat Springs area later today into Tuesday. Relatively warm showers should start later this evening and peak during the overnight hours, with the snow level near the top of Mt. Werner.
Light showers may persist in the cool northwest flow behind the small storm on Tuesday, but should end later in the day as the atmosphere dries and stabilizes under a building ridge.
Warm and sunny weather should return for Wednesday and Thursday before additional energy dropping southward from the Aleutians forces the Pacific Northwest storm to elongate and move eastward. The storm is forecast to split, with the the tail end of the northern branch bringing a dry cool front through the area on Friday as it moves across Montana.
Meanwhile, the southern end of the split makes landfall around central California on Friday and mixes with a topical system moving northward from Baja. Current model forecasts have the ridge rebuilding behind Friday’s cool front, so it is unclear how much of this energy will make it to the Steamboat Springs area by Saturday, but another round of relatively warm showers are possible.
Drier weather should return for the end of the weekend for a short time before more Pacific energy moves what was once the Aleutian storm eastward. Once again, the threat of showers will increase by late in the weekend or early in the next work week as that storm crosses the California coast and moist southwest flow increases.
Thursday, October 20, 2016
A large storm off the West Coast has pumped up a ridge over the western U.S. promising a beautiful weekend with warm temperatures. Additional energy from the Aleutians moving southward this weekend will force the storm to dig southward along the coast, and increasing southwest flow ahead of the storm will direct some tropical and subtropical moisture over the Four Corners states on Monday and Tuesday. The end result will be an increasing chance of rain showers on Monday and early Tuesday for the Steamboat Springs area before drier weather returns as soon as Tuesday afternoon or evening.
There is a fair bit of uncertainty with the evolution of the West Coast storm, with the latest run of the models keeping most of it offshore through midweek, allowing the ridge of high pressure to rebound and bringing warm and sunny weather for Wednesday and Thursday.
If current model forecasts hold, the trough will elongate and undergo a modest split, with the southern portion making landfall around the end of the work week and directing another round of tropical and subtropical moisture across California and into the Great Basin. It is unclear whether this moisture and energy will be close enough to the Steamboat Springs area to threaten warm showers next weekend or whether the western ridge will be strong enough to deflect the weather to our north.
Monday, October 17, 2016
A couple of waves of energy moving within a strong Pacific jet stream will affect our area today and later Tuesday into Wednesday. Though I just saw some snowflakes in the valley, the rain-snow line looks to be around 7500′ - 8000′ and the current rain showers, mixed with snowflakes at times, should persist through most of the afternoon.
We should have a break in the precipitation tonight lasting into Tuesday afternoon before a stronger wave brings a cold front through the Steamboat Springs area late in the afternoon or early in the evening. Snow showers, moderate to heavy at times, should occur overnight Tuesday even in the valley, likely leaving accumulations on the grassy areas and possibly even the roadways under the heavier showers.
Wednesday will be quite chilly, especially with a trailing wave keeping the possibility of some light and non-accumulating snow showers over the area through the day.
Thursday should be a sunny and cool day with warming afternoon temperatures as a flat ridge builds behind the departing storm, with the coldest morning temperatures of the season if skies clear by sunrise.
The ridge will bring dry and pleasant weather with much warmer temperatures for Friday and the weekend, with a dry wave passing over the top of the ridge knocking temperatures back a bit on Sunday.
A complicated and uncertain upper level pattern then evolves off the West Coast early in the next work week, possibly bringing the threat of precipitation back to the area, especially by midweek.