A south–north oriented precipitation band is slowly moving across the Utah and is likely to be bringing periods of rain, possibly heavy at times, this afternoon and during the Ute football game this evening.
The forecast from the High Resolution Rapid Refresh (HRRR, courtesy NOAA's Earth Systems Research Lab), which will become operational in the near future and provide short-range forecasts at 3-km grid spacing for the continental United States, shows bands of heavy showers moving through the Salt Lake Valley prior to and during the game, with just a few short-lived breaks. Here are the hourly radar reflectivity forecasts for 2300 UTC (1700 MDT) through 0400 UTC (2200 MDT).
The HRRR lightning threat product shows the potential for some lightning during this period (one time selected for brevity).
The bottom line is that a Washout Game is on tap for tonight, with the potential (but not a guarantee) for a lightning delay.