The record high for today is 92ºF, which is also the latest 92ºF day in the record books at the Salt Lake City International Airport. As of 1:35 PM, it was 89ºF at the airport. I'm guessing a 91ºF max is probably most likely, but maybe we can squeeze out a record.
Tomorrow there's a chance of showers and thunderstorms as the upper-level trough approaches, afterwhich your ark-construction needs must be complete as the system taps into juicy air over the eastern Pacific and Gulf of California. The forecasts below show the forecast integrated water vapor transport produced by the GFS (bottom) and the average of all members of the Global Ensemble Forecast System (GEFS) on Saturday morning. There is a narrow plume of strong water vapor transport extending from Baja into Utah.
Moisture transport of the intensity forecast is fairly unusual in the Intermountain West this time of year, with return intervals of about once every 10 years in late September and early October.
There is, however, quite a bit of spread and much is going to depend on timing and location. By and large, Saturday looks like a fairly wet day. Those of you heading to the Utah–Wazzu football game should keep an eye on the forecast and hope for a break. Coach Wittingham might want to consider having his players practice with wet footballs today and tomorrow. There's even a possibility of thunderstorms, so hopefully the University has an appropriate lightning safety plan in place as we have discussed previously. Kudos to the University of Michigan for taking proper precautions last week.
In case you are wondering, it appears that there have only been five calendar days during which more than 2 inches of rain was recorded at the Salt Lake City Airport (or probably downtown for really old observations), but two of those days are in September.
May 3, 1901
June 5, 1885
July 13, 1962
September 5, 1970
September 26, 1982
September is a good month for a deluge because of the combination of monsoon moisture with cool-season storm systems. I won't be surprised if we see some locations with 2+ inches on Saturday.