Cool fronts today and Wednesday
Sunday, September 8, 2019
This beautiful and sunny Sunday morning in Steamboat Springs will give way to an active weather afternoon and evening as a storm currently in the Great Basin travels across our area today. Cooler and quieter weather will follow early in the work week before a colder, but drier, storm brings an additional round of active weather through the area on Wednesday. Cooler weather and mostly sunny skies should follow for the rest of the work week and the following weekend.
The approaching storm is currently producing rain showers in Salt Lake City ahead of the cold front moving through eastern Nevada. Clouds will increase later this morning with showers starting around mid-afternoon and continuing through the evening, before they end by around midnight after the cool front passes through.
Monday should feel fall-like with sunny skies and high temperatures several degrees below our average of 75 F. Tuesday will start sunny and cool, with frost possible in the lowest-lying areas before we see increasing clouds and the possibility of an afternoon or evening shower ahead of the next colder, but drier, storm moving across the Great Basin.
The cold front associated with the storm will move through northern Colorado later in the day Wednesday, bringing cooler temperatures and increasing showers and that will last through the afternoon and some of overnight. I would consider this our first fall front of season due to the structure of the storm and the likelihood of snowfall dusting the higher peaks on Thursday morning.
And accordingly, low temperatures on Thursday and Friday will be the coldest of the season so far, with frost likely on Thursday and freezing temperatures on Friday as the mercury dips five to ten degrees below our average of 37 F. So those late-blooming and barely mature plants of the summer will have to be protected to prolong the incredibly short growing season this year.
But we should see plenty of sun later Thursday and Friday which should persist through the weekend, with high temperatures rising from below normal on Thursday to around normal on Friday.
An additional storm develops in the Gulf of Alaska midweek and pushes onshore around Vancouver late in the work week. Any precipitation from the storm is forecast to be to our north, though we may see some cooler, but still likely dry air sink over our region during the weekend. The main effect will be the windy westerly winds that are forecast to develop over much of the west as the Vancouver storm mixes with some cold air from the northern latitudes of western Canada through the weekend.
Several cool fronts for the upcoming week
Thursday, September 5, 2019
The Steamboat Springs area is experiencing another warm and sunny summer morning this Thursday. Several cool fronts will pass through northern Colorado later Friday, later Sunday and again near the middle of upcoming work week, increasing rain chances and decreasing temperatures.
Currently, storms are spinning off the Pacific Northwest coast, the Gulf of Alaska and the Bering Sea as a strong ridge of high pressure sits over the west. There is some monsoonal moisture that is being drawn northward underneath the ridge that may produce some showers around our area later this afternoon and evening, though they will likely produce more wind than rain as the lower levels of the atmosphere are still quite dry.
While the solar heating of the earth’s surface weakens as the sun lowers in the September sky, the jet stream sinks further southward and closer to our area, coincident with a weakening of the ridge of high pressure over the west. And as the sun lowers in the sky, the polar regions rapidly cool, strengthening the jet stream and intensifying storms.
So the jet stream will carry the first storm from the Pacific Northwest across the northern Rockies later Friday, and we’ll see increasing chances for showers on Friday afternoon and overnight ahead of and along the cool front.
Temperatures will cool for Saturday, dropping from ten degrees above our average of 76 F on Friday to around average. There is some dry air behind the front on Saturday which may keep the best moisture residing to our south at bay for at least part of the day, or even the whole day. So the current forecast for Saturday is looking drier than it has the past few days, though there may still be a chance of afternoon and evening showers.
The next storm crosses the West Coast mid-weekend, and is stronger, colder and much further south than the Friday storm. There is brief ridging between the storms, which should allow for a sunny Sunday morning before the second cold front passes through later Sunday.
This will be the strongest cool front we have seen since the snowfall we saw in town on June 23. Since there will be plenty of moisture, not only from the storm itself but from the monsoonal moisture drawn northward in the southerly flow ahead of the front, there is a good chance of moderate to heavy rainfall at times from Sunday afternoon through the evening.
Skies should clear by Monday morning giving way to a beautiful and likely fall-feeling day, with low temperatures several degrees cooler than our average of 39 F and the possibility of frost in the lowest-lying areas.
More of the same is forecast for Tuesday before the third Pacific storm crosses the West Coast later in the day. This one looks to be cooler that the second, but not as wet as the monsoonal moisture is forecast to stay well to our south. There is disagreement among the weather forecast models with respect to the eventual strength and timing of the storm, but based upon the American GFS, we could see increasing clouds on Wednesday in advance of the front and a good shot of moderate to heavy rain at times later Wednesday that could continue into the overnight hours.
Thursday and Friday look to be cooler and mostly dry, though there will be a chance of showers in the cool and unstable northwest flow behind the storm on Thursday afternoon.
Weather forecast models are currently agreeing that the following weekend will be dry, though they disagree on whether temperatures will be warmer than or closer to average.
After some of the hottest days of the summer moisture returns midweek
Sunday, September 1, 2019
The weather is warm and dry in Steamboat Springs this Sunday morning, with some of the hottest days of the summer on tap for today and Labor Day. We may be a bit cooler on Tuesday as a weak cool front grazes northern Colorado before moisture begins to overspread our area starting midweek. The increasing clouds will help cool the unseasonably warm temperatures before showers become more likely starting Thursday and extending through some of next weekend.
Currently, a stout ridge of high pressure, sandwiched between a disturbance off the Pacific Northwest coast, a large and cold storm over Hudson Bay and hurricane Dorian off the east coast of Florida, sits over the western two thirds of the nation. Precipitation chances will be practically nil for today and tomorrow as temperatures soar to over ten degrees above our average of 77 F. Many locales in the west will threaten high temperature records not only for the day, but perhaps the month of September as well.
Energy ejecting out of a cold storm near the Aleutian Islands will split as it interacts with the Pacific Northwest disturbance tonight, with some racing across the northern states and some left behind as an eddy that stays off the coast.
The first piece of energy traveling to our north looks to drag a weak cool front across northern Colorado early Tuesday, tempering the high temperatures for the day a bit, though they will still be well above average.
More energy ejecting out of the Aleutian storm undergoes a more complicated split around Tuesday, with some nudging the Pacific Northwest coast eddy eastward across the northern states and some digging further south along the West Coast. The developing disturbance off the West Coast will turn our winds to be more from the south, which will draw monsoonal moisture from the south northward over our area starting on Wednesday.
Shower chances will start to increase on Wednesday, though typically on the first day of a monsoonal surge, any storms that do form will produce more wind than rain as the lower levels of the atmosphere are dry enough to force any precipitation to evaporate before it reaches the ground.
We’ll have much better shower chances on Thursday and Friday, possibly including the overnight periods, as the upper level moisture mixes downward and becomes better established.
Meanwhile, the Aleutian storm is forecast to move eastward in a rather disjointed way, creating forecast uncertainty for the weekend and the following work week. Some sort of storm off the West Coast will likely form during the weekend, even as additional Pacific energy keeps an active storm track upstream over the northern Pacific.
At this point, there may be a downturn in shower chances for Saturday before they increase again for the end of the weekend as the West Coast storm approaches. Interestingly, despite the disagreement early in the following work week, weather forecast models agree that our first fall front may approach later in the work week as the summertime ridge of high pressure over the west loses strength thanks to less solar heating and a stronger jet stream.
Some moisture around today and Friday before hot and dry weather returns for the weekend
Thursday, August 29, 2019
After a couple of cool nights with low temperatures in the thirties and scattered areas of frost, some higher level moisture has infiltrated the Steamboat Springs area this Thursday morning. Our best, but still modest chance of wetting rains occurs on Friday before hot and dry weather returns for the long Labor Day weekend.
Currently, our area is underneath a flat ridge of high pressure sandwiched between a large and cold storm that extends from near the North Pole southeastward towards Hudson Bay and a storm in the Gulf of Alaska. Moisture drawn from the west and south has produced some mid and high level clouds over our area today, with only a small chance of a weak storm that would produce more wind than rain thanks to the dry lower levels of the atmosphere.
We should have a better chance of some storms producing rain that actually reaches the ground on Friday afternoon as the atmosphere has had a day to moisten as the mid and upper level moisture mix downward to the surface.
By Saturday, both the Gulf of Alaska and the Hudson Bay storm move eastward, allowing the ridge of high pressure to amplify over the Rocky Mountains. Warming and drying occurs as the winds turn from the north-northwest on Friday to the west on Saturday and eventually the southwest by Labor Day. In fact, Labor Day may end up being one of the warmest days of the summer, which is appropriate irony considering the late start to summer which included snowfall in town on both June 21 and June 23.
Early in the work week, there is considerable disagreement among weather forecast models and their trends regarding the fate of the Gulf of Alaska storm as it is forecast to undergo some degree of splitting as it approaches the Pacific Northwest coast around Sunday night. Currently, there is a good chance of a weak monsoonal surge of moisture reappearing as early as Tuesday over our area and lasting in some form through the work week, though it is not clear if it will be strong enough to produce wetting rains.
Also of note for the the southeastern corner of the U.S. is Hurricane Dorian, which is expected to eventually be a Category 4 hurricane. The speed and track of major hurricanes are notoriously difficult to predict, but current forecasts have the storm making landfall around the east coast of central Florida on Labor Day before re-curving to the north and slowing or stalling over the Georgia / South Carolina area during the work week.
The weather for the following weekend over Steamboat Springs will be highly dependent upon the evolution of the Pacific Northwest storm and how much energy is left behind off the West Coast after the storm splits. Some models have upstream Pacific energy absorbing the leftover storm and carrying it over our area by the weekend, leading to a much better chance of precipitation.
Warm and dry with some wind for the upcoming week
Thursday, August 22, 2019
The warm temperatures experienced the last two days in Steamboat Springs will continue for the upcoming week. Though several surges of cooler air will be in our proximity that will be most noticeable on the Front Range, we will see an increase in breezy to windy conditions around and behind the fronts.
The recent high temperatures of five to ten degrees above our average of 80 F will continue today ahead of a cool front that will graze our area on Friday. We will see clouds this afternoon and only slightly cooler temperatures tomorrow behind the cool front, with a chance of showers both today and tomorrow, possibly producing brief periods of locally moderate to heavy rain. Aside from any gusty winds associated with passing showers, winds will veer from the southwest today to westerly or northwesterly later on Friday behind the cool front.
Daytime wind speeds should remain elevated through the weekend thanks to a seasonally strengthening jet stream situated to our north as temperatures once again rise to five to ten degrees above average.
Another weak cool front may decrease temperatures a bit for Monday, though again the effects will be most noticeable for areas east of the Divide.
Meanwhile, by midweek, some Pacific energy that mixed with some cool air in western Canada travels to our north and eventually forms a strong storm around Hudson Bay. Cool air drawn southward along the western side of the storm will keep at least the central part of the U.S. cool, and while it is a good bet that the Front Range will see the cooling, it is not clear if the cool air will make it far enough west to cross the Divide and affect our area on Wednesday.
After midweek, there are a couple of opportunities for moisture to increase over our area; first from a tropical disturbance currently off Baja that moves northward along the West Coast during midweek before being absorbed by the clockwise flow around the ridge and eventually directed eastward towards our area, and second from a possible brief reappearance of the North American Monsoon over our area as southerly flow underneath the ridge transport moisture northward.
The end result will be our best chance of showers in two weeks as we head into the long Labor Day weekend. However, what happens for the second half of the weekend is uncertain as it is dependent upon the path and speed of a strong storm forecast to travel across the Gulf of Alaska and how it affects the ridge of high pressure over the West.
