Hot and showery weather ahead of our first cold front around Sunday night

Thursday, August 27, 2020

Temperatures in the mid-eighties and partly cloudy skies are over the Steamboat Springs area this Thursday mid-afternoon. We’ll see continued hot temperatures through the weekend, with afternoon and evening showers possible until the first cold front of the season passes through northern Colorado around Sunday night. And as if to highlight the coming of meteorological fall on Tuesday, the first of September, there may be some snowflakes at the highest elevations of Colorado around Sunday and Monday nights as we finally see temperatures drop to below average for a couple of days.

Currently, a ridge of high pressure over the central and southern Rockies is surrounded by rapidly weakening hurricane Laura to the southeast, storms to our north and a dry area of low pressure over northern California. Monsoonal moisture traveling northward along the western side of the Rockies ridge will remain over our area through the weekend, and portions of the storm to our north and then northern California will combine with the moisture for the chance of afternoon and evening storms. While most of the rain should be light and showery, there is the possibility of brief moderate to heavy downpours around the strongest cells.

A big pattern change comes to our area around Sunday night with the arrival of our first cold front of the season. A storm currently in the Gulf of Alaska is forecast to mix with some cold air from the North Pole and shift our winds to be from the current southwest to the west on Sunday and the northwest by Monday. There may be enough moisture around for some snowflakes at the highest elevations of Colorado, though it is not clear if that happens Sunday night and/or Monday night when a trailing wave passes through.

The most noticeable effect on our weather will be the much cooler temperatures on Monday and Tuesday, with lows in the thirties, below our average of 41 F, and highs falling from five to ten degrees above our average of 78 F before the first front to five to ten degrees below average after the front. Much drier air and breezy northwesterly winds will then invade our area as a stable ridge of high pressure builds over the Gulf of Alaska, keeping this pattern going through the work week.

And while daytime temperatures will warm back towards average starting around midweek, several waves of energy traveling along the eastern side of the ridge look to periodically mix cold air from northern Canada and keep cool morning temperatures in the thirties. After such a hot summer, next week should certainly have hints of fall.

The ridge of high pressure over the Gulf of Alaska is forecast to amplify by next weekend, which might enable Pacific energy traveling over the top of the ridge to again mix with cold Canadian air and bring another cold front through our area around the end of the following weekend or early the next work week.

I should have a better idea of whether we see any snow-dusted peaks early in the coming work week by my next regularly scheduled weather narrative on Sunday afternoon.