Summer weather begins Saturday

Thursday, May 28, 2015

Our long-delayed summer weather begins on Saturday, but not before the wave currently affecting our area leaves more rain today and Friday. Rainfall should end by early Saturday as the wave moves east of our area.

Saturday should start out cool, but temperatures will begin to warm during the day. The cool airmass left behind will likely support storms of minimal strength and it’s possible we may even have a rain-free day for the first time in about 3 weeks, though that hope may be threatened by a very weak wave passing north of our area by late in the day and overnight.

The upper-elevation snowpack will see its first above-freezing low temperatures in three weeks Saturday night, signaling the beginning of its melting and contributing to increasing river flows, especially early next week as it may take a day for that water to make it to the Yampa river.

The warming temperatures will certainly make the weather feel summer-like, and yield typical summer afternoon thunderstorms Sunday through Tuesday.

A wave traveling across the northern third of the US will clip our area and knock temperatures back on Wednesday, as well as the strength of the afternoon storms. There is a possibility, however, that rain will be more persistent late in the day and overnight.

A much stronger storm crashes into the California coast around Thursday, though there is a significant amount of dry air ahead of the storm that will be brought over our area through the end of the workweek as the flow backs to the southwest. The evolution of this wave is complicated as it is not clear how much splitting will occur and how much of the cold air still in the Canadian plains will be drawn into the system, but this may threaten next weekend’s weather.

Generally, for the longer term, there is additional Pacific energy forecast to enter the West Coast as well as a westward expansion of the cool airmass over the Canadian plains. The combination of these is forecast to inhibit the West Coast ridge from building, keeping our weather on the seasonably wet side through at least mid-June.