The La Sals and Abajos can have monsoon rains, usually mid July through September and are somewhat similar to the San Juans or the Mogollon Rim, but the monsoon isn't quite as strong.

The Uintas have thunderstorms in July through early September and are similar weather wise to the Colorado mountains.

The Southern Wasatch can have thunderstorms, but not nearly to the extent of the Colorado ranges, the Mogollon Rim or the Uinta Mountains. Although they do happen occasionally, thunderstorms are rare enough in the Wasatch that the afternoons are probably the most popular time of the day to be on top of a peak.

Although the Southern Wasatch (or the rest of the Wasatch for that matter) have much less thunderstorms than the Uintas or the Colorado ranges, they typically get a lot more snow and are much wetter in the winter. Unlike much of Colorado, Arizona and much of Southern Utah, summer is by far the driest season in the Wasatch. See the below weather chart for Alta, for example:

http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?utalta

Except for Mount Nebo ...

Mount Nebo is in the southern Wasatch, and gets pounded with monsoon activity, a.k.a. flash flooding, during the summer months.

I was witness to one, where I had to spend the night stranded inside my compact car.

You also have to consider the fact where there has been a previous large wildfire, there will be a greater chance for flooding.

If you're willing to spend the night inside your car with a warm beer, you should be okay.

Lionel, you're definitely on the RIGHT track ! Yep, just like the train.

The southern slopes of the Uintas receive far less precipitation than the northern slopes.

The strength of the annual monsoon varies each year. I'm hoping for a whopper of a stormbringer for 2011, so I can cool down
my blood pressure and get some relief from the heat.