Thursday, August 17, 2017
A surge of cool air moving southward from the North Pole has created a wave in the polar jet stream that is currently passing through Montana and the Dakotas A weak cool front associated with this wave will be dragged through the Steamboat Springs area overnight with little sensible effects on our weather.
The western ridge rebuilds behind the wave, bringing warmer temperatures and drier air for the weekend, with only a small chance of afternoon storms. Concurrently, another surge of cooler air from the northern latitudes produces an additional wave that crosses the southern British Columbia coast on Friday. This will temper the strength of the ridge as the bulk of the storm again travels north of our area.
Notably, part of that wave splits and forms a trough of low pressure off the California coast that loiters there for at least part of the work week. As this trough forms over the weekend, the upper level flow backs from the northwest to the southwest, and mid and upper level moisture increases by late in the weekend, especially for areas to our south.
This could threaten the viewing of the 2017 solar eclipse on Monday, though right now it appears there is enough dry air lurking to our north to keep the clouds at bay for the Steamboat Springs event. Areas further south might not be as fortunate. And for those traveling north to Wyoming to view the spectacle, the chances for mostly cloud-free viewing are higher.
The western ridge is forecast to amplify further through the work week, bringing even warmer temperatures to the area. While models eventually move the California trough eastward, attendant with good chances for rain, the European ECMWF has trended slower than the American GFS. The slower solution allows the western ridge to rebuild, and the ECMWF then has the trough lifting northwest of our area, keeping conditions much drier than the American model for the end of the work week.