Monday, October 30, 2017
A couple more cold fronts will pass through the Steamboat Springs area this week, with the first reinforcing the current cool temperatures and bringing the possibility of snow showers around midnight and early Tuesday morning. Some dry air to our north will move over our area in northwest flow after the morning, and we should see a dry but chilly Halloween afternoon and evening.
Temperatures will warm to normal for Wednesday before another cool front in northwest flow passes over northern Colorado on Thursday. Though we will see temperatures knocked back a bit and there will be some clouds, the bulk of the moisture stays to our north.
Friday will feature dry conditions with some warming ahead of a complex storm that forms in the Gulf of Alaska thanks to some Pacific energy traveling over a ridge of high pressure in the Bering Sea and mixing with some cold air from western Canada. The storm will split off the West Coast during the weekend, with our area forecast to be under the influence of the southern part of the storm on Saturday and both parts of the storm later in the weekend or early next week.
It is no surprise there is uncertainty regarding the evolution of this storm, but right now some low elevation rain showers and high elevation snow showers are expected around Saturday afternoon before they end ahead of the cool front associated with the northern part of the storm. This front is expected later Sunday afternoon or evening with showers, though at this point it may or may not be cold enough for snow in the Yampa Valley.
By Monday, showers will increase and snow levels will rise as the cool front is chased back north by energy ejecting out of the southern part of the storm. At least one numerical weather forecast brings the southern part of the storm through the Great Basin and affects our area with low elevation rain and high elevation snow for later Monday and Tuesday, ahead of a break in the active weather pattern advertised for midweek.
Thursday, October 26, 2017
A weak storm currently in Wyoming will travel through the Steamboat Springs area today, with temperatures staying cool and some snowflakes possible later this afternoon. The cool front associated with the storm is fairly dry, and Friday should be a mostly sunny but chilly day behind the storm.
A very weak wave in northwest flow will pass over our area on Saturday, and may bring some clouds and the slightest chance of precipitation as temperatures warm back toward seasonable levels.
There are lots of moving pieces for later Sunday and beyond, with the remnants of former typhoon Lan traveling over and through a ridge of high pressure off the West Coast. The disparate numerical model solutions from my last forecast have indeed come to a messy compromise, with some energy from the former typhoon being left behind underneath the ridge off the West Coast, but most traveling over the ridge and dropping into the Midwest early in the work week.
This will lead to a weak and mostly dry cool front grazing our area later Sunday after a day of seasonable temperatures, bringing some cooling temperatures that will be reinforced on Monday and Tuesday by additional grazing energy traveling southward from the higher latitudes into the Midwest.
Temperatures will briefly warm for some of Wednesday before additional Pacific energy splits as it interacts with the West Coast ridge and forces it westward toward the Bering Sea. Most of the energy will break off and carry a chunk of cold air westward into the Gulf of Alaska forming a persistent storm system that will stay mostly in place for the rest of the work week. Some of the energy, however, will continue traveling to the southeast and bring another grazing cool front into northern Colorado later Wednesday into Thursday.
Temperatures should rebound to seasonable levels for the end of the work week and the weekend as we experience a brief break in the parade of cool fronts. However, longer range models do indicate that additional Pacific energy traveling southward along the east side of the new Bering Sea ridge will eventually dislodge pieces of the Gulf of Alaska storm around mid-weekend. This may begin a stormy pattern for parts of the West, including our area, around the start of the new work week.
Monday, October 23, 2017
A weak storm that passed through the Steamboat Springs area earlier today has exited the region, with skies clearing and temperatures rebounding behind the quick-moving disturbance. Dry weather and warming temperatures are on tap for Tuesday and especially Wednesday ahead of another storm timed for Thursday. Winds may become breezy Wednesday afternoon ahead of the storm.
This storm has trended further east and drier with successive numerical model runs, but the forecast for colder temperatures has persisted. The front is forecast to pass through northern Colorado during the day Thursday, accompanied with some light snow showers down to the Yampa Valley floor.
Cooler than normal temperatures will persist for Friday as trailing energy reinforces the cool air and keeps some clouds around, but there should be no additional precipitation.
The weekend look warm and beautiful ahead of a possible early-week storm which will contain the remnants of typhoon Lan. Currently affecting Japan, the storm will be absorbed by the Pacific jet stream and move over the top of a ridge of high pressure that builds near the West Coast this weekend.
Significant forecast differences persist between the numerical weather models, and it relates to the location and size of the West Coast ridge. The American GFS keeps the ridge strong and most of the storm travels north and east of our area in northwest flow, with a glancing blow of cooler air and some precipitation later Monday. The European ECMWF is more aggressive with the storm, moving it through the ridge and keeping it further south and west. Ironically, the more aggressive solution keeps Monday nice for our area as the storm digs into southern California, before possibly phasing with some cold air from the north around Tuesday as it moves along the southwestern U.S. border.
I have no preference for either model at this point, and would suspect some sort of compromise solution emerges, which I will write about in the Thursday forecast.
Thursday, October 19, 2017
After another gorgeous fall day today, the Steamboat Springs weather for Friday will be changing thanks to a storm currently crossing the Pacific Northwest coast. As the storm moves across the Great Basin tomorrow, moisture and winds will increase ahead of a sharp cold front, similar in strength to last Saturday’s storm. There may be some rain showers ahead of the front tomorrow afternoon, but most of the precipitation will be in the form of snow along and behind the windy cold front Friday evening and overnight as temperatures plummet over twenty degrees.
Snow showers will end Saturday morning followed by partly sunny skies, breezy conditions and relatively cold temperatures. We will get some warming for the first half of Sunday before another storm, rotating through the Gulf of Alaska, travels along the U.S. - Canadian border and brings another surge of not-as-cold air and some clouds for later Sunday.
The storm is forecast to sag into the northern Great Plains on Monday, and while showers will likely stay to our north and east, clouds and some cooler will stick around into Tuesday.
Much drier air and much warmer temperatures are expected for Wednesday ahead of another Gulf of Alaska storm approaching our area from the northwest. Numerical weather models have trended further south and west with this storm over the last few runs, and at this point it looks like another cold front approaches our area on Thursday.
For the following weekend, we may be affected by the remnants of typhoon Lan, currently threatening parts of Japan this weekend. Hurricanes form in the Atlantic and eastern Pacific, while typhoons are their counterpart in the western Pacific. Because they often spend longer periods of time over warm open waters, they can be even more powerful than hurricanes, with the strongest becoming super-typhoons.
Typhoon Lan, which may fall into the super-typhoon category, is forecast to be absorbed by the Pacific jet stream after the weekend and might impact our weather next weekend. Of course, to get the next weekend forecast right for our area, the typhoon needs be accurately forecast for Japan this weekend, which is a tall order. If current model forecasts are to be believed, much cooler and unsettled weather might end this month and start the next one.
Monday, October 16, 2017
High pressure is in control of the weather for almost the entire United States, and this will bring more warm and dry days with cool nights for the Steamboat Springs area through most of the work week. A quick moving storm along the northern U.S. border may knock temperatures back a bit for Wednesday, but the dry weather will persist until later Thursday when a stronger Gulf of Alaska storm crosses the West Coast and affects our region through the early part of the weekend.
As this moves eastward, southwest winds first carry some moisture northward, bringing some high and mid-level clouds to the area later Thursday and possibly some light showers by Thursday night. As the storm moves across Idaho on Friday, southwest winds will increase over our area and become breezy to windy, with showers becoming likely by later Friday ahead of a cold front currently timed for Friday night.
Showers will stay as rain in the Yampa Valley ahead of the front before changing over to snow by overnight Friday. Like the last Saturday storm, this one will also be quick moving, bringing a cool start to the weekend with showers ending early in the day.
High pressure builds in behind the storm for a nice Sunday, though there is some uncertainty for early next week regarding additional Pacific energy that will carry some more moisture and winds inland across the Pacific Northwest. This energy may sag far enough south to bring some clouds and slightly cooler temperatures for Monday and Tuesday, or stay north of the area for less clouds and warmer temperatures.
It appears La-Nina is back in the news, as the National Weather Service issued an advisory last Thursday indicating a 55%- 65% chance of a La-Nina winter. El-Nino is a warming of the ocean waters in the southern Pacific, while its counterpart, La Nina, is a cooling of those same waters, and its appearance can affect global weather patterns. Closer to home, El-Nino is associated with a strong, relatively stationary ridge of high pressure in the eastern Pacific, while La-Nina has a much suppressed or even absent ridge.
While some weather forecasters insist that all of Colorado is affected by El-Nino or La-Nina, the fact is that northern Colorado is not well correlated with either. During El-Nino years, the location and amplitude of the ridge of high pressure in the Pacific is critical, and the Steamboat Ski Area may be in favorable northwest flow if the ridge is far enough west, or benign weather if the ridge is further east and closer to our area.
However, the suppression or absence of the ridge during La-Nina years means that storms moving across the Pacific are not influenced by a relatively stationary weather pattern. This tends to keep the storms moving, and long stretches of either quiet or stormy weather are less likely. In my view, an accurate seasonal forecast for northern Colorado based upon the slightly-better-than-chance probability of a La-Nina event, combined with the absence of strong correlations in our area to that event, is impossible.