DENVER -- Thursday will tie for the warmest day so far this year at 86 degrees in Denver, Boulder and Fort Collins.
Skies start sunny, then there is a 10% to 20% chance of afternoon thunderstorms.
The mountains can expect gusty winds above treeline. It will be dry in the morning, then isolated afternoon thunderstorms. Highs will be in the 50s, 60s and 70s.
The summer solstice occurs at 9:54 a.m. on Friday. But, it's not going to feel like summer this weekend.
An abnormally large dip in the jet stream delivers a 15- to 25-degree temperature drop across Colorado.
Snow is likely on the 14ers between Friday and Sunday with 1-3 inches of accumulation. Gusty winds are likely above treeline.
Plans for rafting, camping, hiking and mountain biking will be affected. Overnight mountain lows in the teens and 20s are possible.
Rain and highs only in the 60s are likely across the Front Range from Friday afternoon to Sunday.
It will be drier and warmer starting Monday with the first 90-degree day possible next week.
The average for the first 90-degree day in Denver is June 10. The latest on record is July 21, 1967.
Pinpoint Weather has been independently certified as Colorado's Most Accurate Forecast by WeatheRate.
We're tracking weather today on FOX31 Denver and Channel 2 News - and when conditions are bad we send out the Weather Beast.