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.
