How do the Abajos, the LaSals and for that matter, the southern Wasatch or the Unitas compare to places like the Mogollon Rim, the White Mountains, the Sky Islands, the San Francisco Peaks, the Sangres, San Juans, the Elks, and the Sawatch, respectively in Arizona, New Mexico and Colorado in terms of Monsoon activity? It may purely have been coincidence, but last summer when travel to Wyoming through Utah, I was able to see storms in Colorado, and we had good storms in Arizona, but every place I was in Utah was more or less dry. It was also dry and storms were absent in the Tetons, despite them having killed a climb a couple of weeks before. It was actually "Arizona June-Like" when I was in Bryce, but monsoon like in Zion.


So my question is: is there a slight rain shadow type effect on Utah from high elevation areas further south, or was it just pure coincidence that I observed virtually no monsoon activity in most of Utah, despite being able to see it in Colorado or having experienced it in Arizona the day before entering UT?

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.

It makes sense that even on an active day, the Abajos and LaSal would not be as wet as the San Juans, since they are not as large and can't cause as much uplift. I must have gone over the Unitas by Flaming Gorge on an inactive day, because it was clear and dry. Sometimes, it really doesn't require much rain to produce a substantial and violent flash flood, so while the Wasatch can be dry, I can see flash flooding being common there. It happens in the eastern Sierra, despite that areas lack of regular summer rain.

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.