Nice weather turns unsettled near the end of the work week
Monday, May 29, 2017
Energy traveling southward along the western periphery of a large storm near the Great Lakes has kept seasonably cool temperature in place for the Steamboat Springs area. There will be a threat of afternoon and early evening storms today, with gusty winds likely as most of the precipitation will evaporate in the dry sub-cloud layer before reaching the ground (virga). This evaporation will cool the air beneath the cloud, forcing it first downward as it becomes negatively buoyant and then outward as it encounters the ground.
The diffuse area of low pressure talked about in the last forecast looks to stay south of northern Colorado through midweek, allowing a ridge of high pressure to build over the Intermountain West. Mostly sunny skies and warm temperatures are expected with only a slight chance of afternoon storms for Tuesday and Wednesday.
A splitting Pacific trough of low pressure approaches the West Coast midweek, and the first effects will be much increased chances of afternoon storms on Thursday as some moisture to our south is carried northward by the southwest flow ahead of the trough.
The southern end of the splitting trough looks to move over Colorado on Friday, bringing a weak cool front through the area with showers likely during the day.
By Saturday, Colorado will be caught in the somewhat chaotic and slow-moving area of the split flow, leading to more chances for showers, though likely less numerous and intense than on Friday.
On Sunday, the Steamboat Springs area looks to be in either drier flow from the southwest or moderately unstable flow from the north as some of the northern split interacts with more energy rotating southward from central Canada. At this point, the forecast could be either dry or unsettled.
Models agree that another storm will cross the West Coast late in the weekend, but disagree on its position. The Amercian GFS has the further south solution compared to the European ECMWF, and would bring another round of cooler temperature, showers and unsettled weather for the beginning of the new week.