Cool, moist air will cover much of southeast Colorado today...with thunderstorms developing over the mountains...then spreading onto the plains in the afternoon. Slow moving thunderstorms could produce locally heavy rainfall...along with small hail and dangerous lightning. Temperatures could be a few degrees warmer...but will still be below seasonal average. Tuesday will be drier over the Plains with the Continental Divide receiving the majority of the rainfall and thunderstorms. Wednesday and Thursday bring a major shift in moisture as a new surge of monsoonal rainfall moves into the area. Heavy rain is expected through the mountains and foothills with a significant increase in flood and flash flood potential Wednesday and Thursday. Stay alert as this potentially dangerous situation develops. (Please visit http://weather.gov/pub for more information.)