Thursday, September 29, 2016
An incoming Pacific storm to our northwest and tropical and sub-tropical weather systems to our southwest will affect the Steamboat Springs weather over the next week. Southwesterly flow ahead of the Pacific storm, currently located off the Pacific Northwest coast, has brought moisture left over from last week’s storm and a tropical storm near Baja over Colorado. There is a good chance of nocturnal showers tonight as a wave of energy moves just west of Steamboat Springs after midnight.
We will also have a good chance of showers during the day on Friday as the airmass continues to moisten and additional energy from the southwest travels over the area.
Drier air invades the area for the weekend in still warm southwest flow with afternoon showers possible, more so on Saturday than Sunday.
Meanwhile, some cold air from western Canada will mix with the Northwest Pacific storm, causing it to split with a significant part of the storm forming a closed low that sinks southward along the West Coast over the weekend. By Sunday, the Pacific jet stream undercuts a transient ridge in the Gulf of Alaska and forces the closed low to make landfall around northern California.
The storm will move across the Great Basin on Monday, with relatively dry southwest flow ahead of the storm keeping warm conditions over our area with a slight chance of Monday afternoon showers.
However, the summery weather will come to an abrupt end Monday night as current forecasts have a strong cold front associated with the storm moving through the area. We will likely see moderate to heavy precipitation with the front, and snow levels will plummet to the valley floor, with the season’s first snowflakes likely falling in town on Tuesday. The warm road surfaces will likely preclude accumulations, but snow on the grassy surfaces is certainly possible.
Additional energy will keep the precipitation going on a likely dreary Wednesday with brisk northwest winds before current forecasts have the storm moving east of our area by Thursday. For those that plan travel to the East Coast over Columbus Day weekend, be aware that long range models have a hurricane threatening the East Coast for the end of the work week. There is lots of uncertainty, though, as not only may the track of the hurricane change, but it may or may not interact with either our last week’s storm currently spinning in the Ohio River Valley or our forecast storm for next week.
Monday, September 26, 2016
A building western ridge will keep warming temperatures and sunny skies with cool nights around through tomorrow and some of Wednesday.
Part of this past weekend’s storm that broke southwestward from the parent circulation is currently spinning near Baja and will be joined by a tropical disturbance moving northward. Meanwhile, additional cold air from the northern latitudes will strengthen a Gulf of Alaska storm and move it southward by midweek.
Southwest flow ahead of the Pacific storm will shear the Baja disturbances into a series of waves that will move northeastward, increasing moisture over our area later Wednesday and leading to the possibility of showers as early as later Wednesday and lasting through Friday.
Following closely on the heels of these Baja disturbances, additional energy starts to eject from the Gulf of Alaska storm that is forecast to be off the Pacific Northwest coast by Friday. This energy will move over the area in continued warm southwest flow, threatening continued showers in warm temperatures through the weekend.
By late in the weekend, numerical guidance has upstream Pacific energy undercutting a rapidly building ridge behind Pacific Northwest storm which forces the storm eastward. Some sort of cool front is forecast to pass through the Steamboat Springs area early in the next work week, followed by cool and unsettled weather as the storm slowly moves across the Great Basin.
Thursday, September 22, 2016
The gusty southwest winds observed over Colorado today are due to the large storm currently residing in the Great Basin that is rapidly approaching our area. There may be a chance of showers later today as pieces of energy are ejected from the storm, but the bulk of the precipitation will occur along and behind the strong cold front, which is timed to pass through the Steamboat Springs area Friday morning.
There should be moderate to heavy showers when the front passes, bringing snow levels down to 8000′ or even lower in the heavier cells. Showers will continue intermittently in the cool, moist and unstable flow behind the front on Friday with some accumulating snows likely around pass levels.
Some energy will dig south from another wave traveling westward through western Canada, reinforcing the cold air and contributing to another cool and showery day on Saturday. Additional trailing energy will keep the cold air around for Sunday, though this piece of energy is forecast to keep moving south, causing the storm to elongate and allowing dry air to infiltrate Colorado from north to south during the day. There should be some spectacular scenery as the sun appears over colorful aspen and snow-covered peaks.
With clearing skies on Sunday and a last push of cool air from energy rotating around the backside of the storm forecast to be to our northeast by then, Monday morning will be cold with a hard freeze likely. Temperatures will be slow to recover under sunny skies until Tuesday when a building western ridge brings temperatures back to or above normal. The ridge will likely keep another round of brilliant weather around for most of the rest of the work week.
There is uncertainty in the forecast for the end of the week as some of the southward moving energy from this weekend’s storm meanders south of the Mexican border and possibly coalesces with a tropical storm moving northward from Baja midweek. The southwest flow ahead of another Pacific Northwest storm moving southward from the Gulf of Alaska late in the work week is forecast to move these southern systems into the southwestern US and they may threaten our weather by next weekend.
Sunday, September 18, 2016
Enjoy the current spectacular weather since a big change is forecast starting around late Thursday or Friday.
In the meantime, sunny warm days and cool nights will persist for Monday and Tuesday as a flat ridge keeps the dry air around. Meanwhile, to our west, some energy left behind by last week’s Great Basin storm is currently spinning off the southern California coast and will be joined by a tropical storm traveling northward from Baja on Tuesday. An incoming Pacific storm from the Gulf of Alaska will mix with additional cold air in Alaska and move southward along the West Coast early in the week, pushing this warm complex across the southwestern US.
Models have struggled with the northward extent of this complex as it mostly passes to our south, but it appears clouds may be the only affect for northern Colorado by Wednesday, similar to way these events developed over the last half of the summer.
Thursday will be a breezy to windy day with southwest winds as the large Pacific storm makes landfall. A wave ejecting from the storm may bring showers to Steamboat Springs as early as Thursday afternoon, though the most noticeable affects will occur when the cold front associated with the parent storm crosses the area later Thursday or Friday.
The exact timing of the front is questionable as the storm elongates to the north and south as energy ejects in both those directions, but models agree that significant cooling accompanied by precipitation will occur for a couple of days, most likely Friday along and behind the front and Saturday when trailing energy keeps showers going in cool, moist and unstable northwest flow. While snow accumulations are a good bet near the top of Mt. Werner, snowflakes could fall to 8000′ or lower by Saturday morning.
Models do have have clearing in continued below normal temperatures by Sunday, though that will be jeopardized if the storm moves slower than currently forecast.
Friday, September 16, 2016
After a cool and unsettled week, dry, sunny and warm days with cool nights return for most of the next week in Steamboat Springs.
While the storm system responsible for last week’s weather has largely moved east of the area, some energy was left behind and is currently residing in the southwestern US and Baja. There was uncertainty in Monday’s forecast regarding this energy and it’s northward extent when another strong Pacific storm kicks it eastward around midweek. Though there is still disagreement, the bulk of that storm looks to stay south of our area, possibly introducing some clouds but likely allowing the beautiful weather early in the week to persist through most of the work week.
The incoming Pacific storm, however, is far more difficult to predict at this time as a complicated pattern consisting of cool air moving southward from Alaska, several waves of additional Pacific energy, a transient building ridge centered in the northwestern US and British Columbia and even a tropical storm moving northward from Baja interact. Current forecasts have the Pacific jet stream eventually undercutting the transient ridge around the end of the work week, allowing the Pacific storm to move eastward and threaten the week of fine weather around late Thursday and Friday.
Incidentally, this is the first event this fall where Pacific energy undercuts a ridge in the vicinity of the Gulf of Alaska, and reflects the growing dominance of a winter-season jet stream. Over the remainder of the fall season, there will battles between a weakening summer-like ridge over the southwestern US and a strengthening winter-like Pacific jet stream. While summer wins the immediate battle, it’s victories will become more sporadic and shorter lived as cold air continues to build in the northern latitudes.