11:15 AM, Friday, August 7, 2015
Expect slightly cooler temperatures, but still warm, with some thunderstorms around this weekend.
There is lots of monsoon moisture south of Colorado, and that moisture extends over Colorado in the middle and upper parts of the atmosphere. As a result there are more clouds around and the chance for thunderstorms is back in the forecast. But because the lower atmosphere is rather dry along the Front Range, the chance of hearing thunder is greater than the small chance of getting rain. There may be some brief gusty winds too. The best chance for strong thunderstorms today and through the weekend appears to be on the plains east of the urban corridor, and in the southern mountains.
Here at the Boulder climate station the warmest temperature so far this summer has been 94 on August 6th. Although this summer has not been nearly as cool as recent cool summers in 2004 and 2009, the lack of 95-degree days is unusual. The weather pattern this coming week may result in some 95-degree days, but with the monsoon moisture so close, we can’t yet rule out increased clouds limiting the afternoon temperatures. It’s not typical, but not terribly unusual either, for August to score the hottest temperature of the year. In the last 66 years in Boulder the hottest temperature occurred 61% of the time in July, with the remaining 39% split nearly evenly between August and June, and one year (1983) had it’s hottest temperature in September.