Thursday, August 3, 2017
A weak and dry cool front has passed through the Steamboat Springs area early this morning as cool air from western Canada was pulled southward along the east side of a building Gulf of Alaska ridge. Smoke from the Montana wildfires was also brought southwards over our area in the north-northwest flow producing the current hazy conditions.
Northern Colorado will be affected by three distinct weather regimes over the next week; a couple more weak cool fronts currently timed for Saturday and Sunday mornings, a tongue of dry air to our northwest associated with the Gulf of Alaska ridge, and a diffuse area of low pressure off the coast of northern California.
Drier air has spread over our area behind this morning’s cool front, and will remain in place until the next weak cool front on Saturday. As is the case today, there is not much moisture associated with the Saturday wave, but there may be some afternoon and evening storms as weak upper-level forcing moves over the area before the drier air briefly returns overnight.
The second weak front for Sunday will be a bit stronger and moister, yielding better chances for afternoon storms.
By Monday, we begin to feel the influence of the low pressure system off of Northern California as energy begins to eject eastward across the Great Basin. These waves will not only carry moisture and energy over our area starting later Monday and lasting through the work week, but will also mix with several more weak surges of cool western Canadian air still moving southward along the east side of the Gulf of Alaska ridge for a good chance of wetting rains each day.
The old Northern California low pressure system is forecast to move across the Great Basin and be east of our area by around next weekend, though the timing is uncertain as models disagree with how quickly cold air drops into the Gulf of Alaska and moves the ridge of high pressure eastward towards the Intermountain region.
Models agree on eventually returning drier air over our area when this happens, though perhaps briefly, as pieces of the new Gulf of Alaska storm may begin affecting our weather soon after that.