High pressure that has been controlling the weather over the past few days will slowly push out of the area today.  This will allow monsoonal moisture to move back into the region.  Expect thickening clouds with developing showers and thunderstorms statewide today.  The best chance for thunderstorm activity today will be in western and southern parts of the state.  Heavy rain could also be possible at times.  Mainly isolated thunderstorm activity is expected for the rest of the state.  Temperatures will be very warm and close to normal today with daytime highs in the 80's.

An upper-level low pressure system will then cross the area tonight, which will make showers and thunderstorms likely in southwestern parts of the state.  These storms will be slow-moving and will mostly likely produce heavy rain and flash flooding along I-80 from the Utah state line to Laramie.  Thunderstorm activity capable of producing heavy rain and flash flooding will then be possible throughout the state on Thursday and Friday as this low pressure system moves east.