DENVER - A weak surge of slightly cooler, but more humid air has pushed into northeastern Colorado this afternoon. This has kept our temperatures mostly in the 80s to around 90 degrees, but it feels pretty muggy outside for the high plains of Colorado.
The increase in surface humidity has helped to create the haze in the skies and has also fostered the development of scattered thunderstorms over the mountains and the I-25 Corridor. The storms are moving toward the east at about 25 mph and will produce more wind and lightning than heavy rain or hail.
Farther to the east of I-25, the atmosphere is a bit more stable, so these storms may tend to weaken as they push to the east of the Denver metro area. Later this evening, the storms will come to an end and skies will be partly cloudy overnight.
Thursday should be a hotter day as the air mass dries out a bit. Highs should return to the mid to upper 90s on the plains with only a slight chance for thunderstorms. In the mountains, expect scattered afternoon storms with highs in the upper 70s to mid 80s.
Friday will be a similar hot and mostly dry day with temperatures back in the 90s at lower elevations and upper 70s to the 80s in the high country. A few thunderstorms will develop on Friday afternoon and there will be a better chance in the evening ahead of a cold front that will move into northern Colorado.
The cold front will not be a strong one, but it will bring down temperatures a little for Saturday and Sunday. Highs will be in the upper 80s to low 90s over eastern Colorado and in the 70s in the mountains. The Western Slope will stay hot, with highs in the mid to upper 90s.
The cooler air will be more humid, so thunderstorm chances will increase this weekend. Some monsoon moisture will also work back into the region, so some of the storms will produce heavy rainfall.