Cool start to the Independence Day weekend before hot and dry weather returns
Thursday, June 29, 2017
A trough of low pressure over the northern plains has brought cooler temperatures to the Steamboat Springs area today. A trailing wave will bring the last cool front in this series through the area overnight, leading to a chilly morning with even the possibility of some frost. The National Weather Service forecast for the Park Range even has the mention of snow flurries for tonight! Still-tender plants in low-lying areas might need to be protected tonight and Friday night with the unseasonably cool temperatures.
As the trough moves eastward, a ridge of high pressure will return to the western states, bringing drier air and strongly warming temperatures for the weekend.
Meanwhile, another Gulf of Alaska storm has mixed with some subtropical moisture and will weaken as it crosses the Great Basin on Sunday. By the time the trough moves over Colorado later Sunday into Monday, the increased moisture and upward motion associated with the trough will bring increasing chances of showers, with the associated clouds moderating the hot temperatures.
A western ridge rebuilds behind the early week storm, bringing hot temperatures for Independence Day. There may be a chance of some afternoon showers, but they should be isolated and brief.
By midweek, the numerical models disagree with the evolution of the western ridge. The American GFS insists on further amplification, bringing even hotter and drier weather to the western states for the rest of the work week, while the European ECMWF has a weakening ridge which allows some Pacific energy to move inland. This would result in more seasonable temperatures with the possibility of afternoon showers starting around midweek.