An upper-level weather system and unseasonably strong cool front will approach the state of Wyoming today.  Expect early sunshine and then clouds will thicken during the afternoon and evening hours.  Isolated to scattered showers and thunderstorms are also expected.  The best chance for precipitation will be across northern, central, and western portions of the state.  However, any storm that develops could produce hail, gusty winds, and periods of heavy rain.  Temperatures will be cooler and below normal for northern Wyoming today, with daytime highs in the 60's and 70's.  Elsewhere, expect seasonably warm temperatures, with daytime highs in the 70's and 80's.  This cool front and weather system will continue to control the weather across the region this weekend.  Expect more clouds than sun with cooler than normal temperatures statewide.  Daytime highs will remain in the 60's and 70's, with some 80's across the far eastern Plains.  Rain showers and a few thunderstorms are expected for the entire state on Saturday, while shower and thunderstorm activity will be limited to the far southeastern corner on Sunday.