Storms for tomorrow and early next week
Thursday, March 30, 2017
A storm very similar to the last storm is currently centered over southern Nevada and will move east-southeast tomorrow and then along the Colorado - New Mexico border Saturday. Given the meager accumulations from the last storm and the fact that the models are showing a pronounced split in the forecast precipitation around the Steamboat Springs area, I am not optimistic we will see much more than clouds and light precipitation from the storm for most of tomorrow. There is a chance of some energy rotating around the storm later Friday and this will be our best chance of up to several inches of snow by Saturday morning at and above around 9000′.
Unsettled conditions will continue on Saturday as the storm spins to our south.
The once-promising storm for early next week has become less consolidated in recent model runs and is now forecast to bring several weak to modest waves through the Steamboat Springs area starting around Sunday afternoon. There will be a chance of snow showers as low as the valley bottom later Sunday and Sunday night as temperatures cool behind the weak cool front, and a better chance of snow later Monday and Monday night as the strongest part of the storm moves over our area.
There is still plenty of time for this early-week storm to evolve, and I won’t even venture a guess at snowfall amounts yet as there has already been a lot of variation even over the last few model runs. Snowfall guesses will have to wait until my next early-week forecast.
As much uncertainty as there is early in the week, models agree that after a seasonably cool Tuesday behind the departing storms, a strong ridge of high pressure builds over the western states bringing much above normal temperatures and dry weather through the rest of the work week.
A couple of storms to bring snows this week
Monday, March 27, 2017
A major spring storm currently in Utah will move across the Four Corners region by tomorrow morning as it forms a large closed circulation cut off from the jet stream. Energy ejecting out ahead of this storm will continue to bring light showers to the Steamboat Springs area tonight with snow levels starting above about 9000′ before lowering to near the valley bottom by the morning. Accumulations will be limited, however, by some dry air being pulled northward overnight, and I would only expect up to an inch or two by the Tuesday morning report.
The weather gets interesting on Tuesday as the southerly flow ahead of the storm taps very moist air from the Gulf of Mexico and transports it northward along the Front Range. A TROWAL with persistent snows will likely develop somewhere west of the Continental Divide on Tuesday as the moist air from the Gulf is lifted above the cooler air near the surface.
There is disagreement among the models about where the area of enhancement will occur, but along with the easterly winds across the northern part of the storm, some areas will pick up 4-8” of snow during the day. I cannot say if Mount Werner will be a beneficiary of the persistent snowfall, but it is a possibility.
Regardless, snows will diminish Tuesday night before ending during the day Wednesday. We could see as much as 6-12”of snow by Wednesday morning if the TROWAL forms over our area on Tuesday, or well less than half that if your snow dances are not dutifully performed tonight.
Conditions will clear later Wednesday with temperatures quickly warming back to above normal on Thursday. Concurrently, another strong storm crosses the West Coast and takes a very similar track across the Great Basin as the current storm.
Models have showers starting by Friday as energy is ejected out ahead of the developing storm. This storm looks to be wetter and colder, possibly bringing significant accumulations to our area from later Friday through Saturday afternoon.
Brief ridging is advertised for Sunday and early Monday before another possibly strong storm affects our area by later Monday. At this point, the European ECMWF keeps the storm much weaker while the American GFS insists on another strong storm that will be colder than the preceding storm.
Four storms over the next week
Thursday, March 23, 2017
The storm which has brought record rainfall to Salt Lake City today will intensify as it moves east of the Colorado Rockies tonight and forms a tightly wound closed low over the southern Front Range. The track and evolution of the storm is not favorable for the Steamboat Springs area as we don’t see a strong cold front or northwest flow behind the storm; in fact there might even be gusty northeasterly winds by Friday morning. While the storm looked promising earlier in the week, I only expect 1-4” of snow on the Friday morning report.
Precipitation will end by noon on Friday as seasonably cooler temperatures return for the day. Temperatures will warm on Saturday as a transient ridge develops behind the departing storm and ahead of the next one currently timed for Saturday night.
This wave will cross the California coast early Saturday and quickly move across the Great Basin during the day as it undergoes a modest spit, starting another round of precipitation for our area around Saturday evening. Even though the storm is considerably weaker than tonight’s storm, it’s structure is more conducive for snow as temperatures are cooler and the northwest mountain-top wind behind the front is favorable for Mt. Werner.
There is disagreement among the short and longer-range models, but 1-4” of snow is possible by Sunday morning with an additional 1-3” during the day before precipitation ends by sunset Sunday.
Brief ridging is now forecast for Monday before a third storm from the Gulf of Alaska moves south across California on Monday and Tuesday, forming a closed low as it approaches the southern U.S. border. Southwest flow ahead of the storm will carry energy and moisture northeastward, eventually spreading showers over the Steamboat Springs area by Tuesday morning.
Interestingly, the European ECMWF has the same closed low, but also has some energy splitting from this wave early in the week, bringing a cool front through our area around Tuesday night. So it is not clear if we receive a relatively warm precipitation event that ends by Tuesday night, or a cooler and more productive event that possibly lasts through Wednesday.
Surprisingly, models come into better agreement in bringing another wave with a similar track to the third storm across California on Wednesday, possibly affecting our weather by later Thursday or Friday for more unsettled weather heading into next weekend.
Three storms bring precipitation back to the region starting Thursday
Monday, March 20, 2017
The near-record temperatures of the last week have moderated today as mid and high level clouds in advance of the next West Coast storm overspread the Steamboat Springs area early this afternoon. The dry lower levels of the atmosphere precluded any precipitation from reaching the ground, and this pattern will remain more or less intact for Tuesday, Wednesday and most of Thursday.
The majority of the West Coast storm is forecast to make landfall in central to southern California later Wednesday and move eastward across the desert southwest on Thursday. Models are still struggling with the storm speed and structure, but it appears that precipitation will start as rain below 9000′ or so by Thursday afternoon or night in southerly flow.
The storm crosses the Rockies Thursday night or early Friday morning as it moves east in proximity of the Colorado - New Mexico border. Winds will turn northerly, though at this point it is not clear if there will be a westerly or even an easterly component, depending on the intensity of the storm as it moves east of our area.
This storm has the potential to leave 5-10” of snow above 9000′ by the time it winds down Friday afternoon, with some snow down to the valley floor by Friday morning as the coldest air associated with the storm arrives.
Brief ridging for the first half of the weekend is likely ahead of the second storm which is forecast to move similarly to the first, though slightly further north. After it makes landfall late Saturday, it moves across the desert southwest overnight and affects our weather from around Sunday afternoon through Tuesday, with precipitation starting as rain again below 9000′ or so. The snow level will drop overnight Sunday, though it may not reach the valley floor until Monday night when the coolest air arrives.
The third storm moves southeastward form the Gulf of Alaska and crosses the West Coast on Sunday. This storm will be colder but not as wet due to its more northern origins, and may briefly form a cutoff low in the desert southwest by Monday. This is normally not advantageous for us, but energy ejected out ahead of this third storm will combine with the departing second storm and keep possibly significant snows down the the valley floor for most of Tuesday.
Another break in the weather is forecast for the rest of the next work week before another storm in this well-advertised active pattern brings the possibility of more snow for the first weekend of April.
Warm temperatures persist through midweek ahead of pattern change
Thursday, March 16, 2017
Winds increased today as a storm passed well to the north of Steamboat Springs and flattened the western ridge of high pressure responsible for our unseasonably warm temperatures. After some clouds move through tonight, the ridge will quickly rebound bringing sunny skies and near record temperatures to our region for Friday and Saturday.
Meanwhile, much further to our west off the coast of Japan, a large storm that formed this week will eject some energy that will undercut and break down the dominant Bering Sea ridge Saturday. This will force a loitering storm currently north of Hawaii eastward, and as it phases with a storm in the Gulf of Alaska the pair will bring some cooling, breezy westerly winds and the possibility of some light afternoon showers for Sunday that may produce more wind than precipitation.
By Monday, the energy ejected from the west Pacific storm will phase with some cold air moving southward through the Gulf of Alaska early in the work week, forming a storm off the West Coast. Late Sunday’s possibly unsettled weather looks more likely Monday and Monday night before the western U.S. ridge briefly reforms ahead of West Coast storm, bringing more warm temperatures to the region for Tuesday and likely Wednesday as well.
Forecast models have the West Coast storm making landfall around midweek, bringing increasing clouds to Colorado on Wednesday and precipitation by overnight. Temperatures will stay warm ahead of the storm leading to snow levels above 9000′ before the storm moves through the central Rockies on Thursday.
As might be imagined a week out, there is uncertainty with respect to the timing of the storm, with the models trending slower with system speed, as well as storm structure, with the American GFS forming a closed low that would bring moderate to heavy snowfall to the Steamboat Springs area on Thursday.
Regardless of how this storm evolves, the storm in the western Pacific is forecast to merge with and intensify the subtropical jet stream, sending another stronger, colder and wetter storm towards the West Coast by the end of the work week. Current model forecasts have another round of brief ridging ahead of this likely major storm heading into next weekend before the storm makes landfall early in the weekend and affects our area later in the weekend.
