Monday, May 22, 2017
The slow-moving storm that started affecting the Steamboat Springs area last Wednesday is currently spinning north of the Great Lakes. A couple more waves of energy will move southward along the western periphery of the large storm bringing reinforcing surges of cold air and more precipitation across our region today and tonight.
Showers will increase again around mid-afternoon and become heavy at times during the late afternoon and early evening. While the bulk of the precipitation will be rain in the valley with more accumulating snows above 8000′ or 9000′, there may be enough cold air for some non-accumulating snow at the lower elevations later in the evening when the last wave of energy moves over the area.
Precipitation should end by midnight followed by some much-welcomed clearing for Tuesday and Wednesday. Temperatures will still be below normal on Tuesday, but warming on Wednesday should bring a classic sunny late-spring day with pleasant temperatures.
Meanwhile, another strong storm is forecast to travel across the Gulf of Alaska tomorrow and mix with more cold air from western Canada as it moves eastward. By Wednesday, the storm will undergo a modest split, with the northern portion moving across the Canadian border and the southern portion elongating across the northern Great Basin as additional energy moves southward from Canada.
The end result will be another prolonged period of unsettled weather likely lasting through at least some of the Memorial Day weekend, as earlier suggested by the European ECMWF and discussed in the last forecast. Periods of heavier showers will occur as a couple of waves of energy move through the Great Basin, followed by partial clearing behind each wave and the usual afternoon showers.
The timing of the waves will almost certainly change by my next forecast on Thursday, but right now the heaviest showers are likely to occur during the day Thursday and again later on Saturday. The periods of heaviest precipitation will also be influenced by quick moving waves of energy from a decaying storm system off the southern California coast, and these may or may not phase with energy from the north.
Lastly, in order to thoroughly complicate the prognostication, the European ECMWF has just forecast a faster eastward movement of the storm, bringing drier and warmer weather for the latter half of the long weekend while the American GFS still holds on to the cool and unsettled weather through Memorial Day.
Thursday, May 18, 2017
A large, powerful and slow-moving late-season winter storm that is currently spinning over the central Rockies has brought close to a foot of snow to the Steamboat Springs area so far. Light to sometimes moderate snowfall is forecast to continue through this evening before tapering off after midnight.
The slow movement of the storm means that we will still be in the cold, moist and unstable northwest quadrant of the storm through tomorrow, leading to showers, moderate to heavy at times, through the day Friday. Some additional snowfall accumulations above the valley bottom are likely.
Only light showers may be possible for Saturday in still below normal temperatures as northwest flow keeps the cool temperatures around. Concurrently, a wave of energy from the Pacific phases with some cool air from western Canada before splitting just upstream of our area by Saturday night. There will be enough moisture and instability to bring a good chance of storms later Sunday lasting into the evening.
A stronger wave of energy moves southward from western Canada on Monday and phases with some energy from the current storm which by then is forecast to be over the Great Lakes. This will keep the cool unsettled around for Monday with another chance of showers and storms throughout the day.
A last wave is forecast for late Monday night or early Tuesday, with showers ending early in the day before drier air overspreads the area in still cool, though warmer, temperatures.
A transitory ridge is advertised to be over the central Rockies by both the American GFS and European ECMWF for Wednesday and Thursday, bringing much warmer temperatures and sunny skies to the region. There is very considerable model disagreement for the end of the week as another storm approaches the Pacific Northwest coast. The European ECMWF phases this with cool western Canadian air and digs the storm toward the Great Basin while the American GFS keeps the storm moving north of the central Rockies. The end result is opposite forecasts for Memorial Day weekend, with the ECMWF forecasting a trough over our area while the MRF forecasts a ridge.
Monday, May 15, 2017
I may have spoken too soon on May Day when I thought Steamboat Springs would see the last snowflakes of the season. A couple of storms, one currently located in Nevada and another much colder winter-like storm located off the British Columbia coast, will affect our area into the weekend.
The first storm will be pushed eastward across the Great Basin by the second storm, and after a breezy afternoon today, we may see some showers this evening as energy is ejected out ahead of the storm.
Temperatures will be seasonably cool tomorrow behind the cool front with showers possible later in the day as the first storm swings south of our area and moves east of Colorado tomorrow evening. However temperatures will have much further to fall on Wednesday as the second storm crosses the Pacific Northwest coast early tomorrow and travels southeastward across the Great Basin.
Current timing has the strong cold front from the second storm sweeping across Colorado sometime on Wednesday. Though there may be clearing ahead of the front, don’t be fooled as there may be a period of heavy but brief precipitation with the front along with unseasonably cold temperatures.
Precipitation will be showery behind the front, with snow down to the valley floor, especially overnight, though warm road surfaces should limit any accumulations to the grassy surfaces.
Though there are model differences with respect to the southern extent of the storm, there should be a time when precipitation, likely in the form of snow, turns more persistent on Thursday as cold, moist and unstable northwest flow occurs on the backside of the slowly moving storm.
Though temperatures will warm from the coldest part of the storm, still unseasonably cool temperatures with showers are forecast for Friday as trailing energy behind the departing storm keeps moist and unstable conditions around.
Temperatures will warm through the weekend from seasonably cool to perhaps average by Sunday, but there will still be a chance of showers on Saturday and a better chance on Sunday and heading into the new work week as additional energy from the northwest moves over the area.
Friday, May 12, 2017
A large storm currently off the British Columbia coast will be reinforced by an upstream Pacific wave moving over a ridge of high pressure centered in the Gulf of Alaska, forcing a series of cold fronts to move across the Great Basin this week. Earlier in the season, the cold fronts would have had more of an impact on the weather in the Steamboat Springs area, but now, the stronger warming associated with longer days and higher sun angles will reduce the strength of the fronts as they penetrate inland.
Ahead of the first cool front timed for Sunday, pleasant weather for today and Saturday may be interrupted by a chance of afternoon storms, most likely over the higher elevations.
While the bulk of the effects of the first cool front will be shunted to our northwest, we should see a few degrees of cooling for Sunday along with dry and breezy conditions.
Dry air will persist for Monday when a second wave, crossing the West Coast further south along southern California, brings another seasonable day with breezy afternoon conditions.
The dry air that was over our region on Sunday and Monday will be pushed southward by the front, bringing a chance of showers for Tuesday.
By Wednesday, the parent storm crosses the Pacific Northwest coast and moves into the Great Basin. There is model disagreement with respect to the storm’s strength and southern extent, but we may feel its effects as soon as later Wednesday when a stronger front with associated showers is advertised to push through our region.
Unsettled weather with much cooler temperatures is a good bet for at least Thursday and Friday as the the storm slowly moves across the Great Basin and over our area.
Monday, May 8, 2017
A storm currently near northern Baja will move slowly across the Desert Southwest tomorrow, bringing wet and cool weather to the Steamboat Springs area starting later Tuesday. Model forecasts show Tuesday night and Wednesday being the wettest period of the week, followed by clearing weather for Thursday and a return to warmer temperatures and the chance of afternoon storms heading into the weekend.
The wet weather Tuesday night is due to a wave of energy ejecting out of the approaching southwest closed low. Additionally, the Pacific jet stream is moving across the Canadian - U.S border, and a wave in that flow will drag a cool front through northern Colorado around then. This will interact with the closed low that is forecast to move across the Colorado - New Mexico border during the day Wednesday and enhance precipitation for Tuesday night and Wednesday.
By later Wednesday, the storm is forecast to be east of Colorado, bringing significantly drier weather for Thursday, though there is model disagreement as to whether there will be enough instability for showers later in the day.
A sharp ridge of high pressure builds over the Rockies behind the departing storm and ahead of a strong Gulf of Alaska storm that is forecast to elongate along the West Coast during the weekend. This will lead to warm mostly sunny days through early next week with the chance of afternoon storms, strongest on Friday as lingering moisture fuels the storms.
It appears the West Coast storm will eventually affect our weather sometime next week, though model disagreement with respect to its movement and strength makes the details uncertain.