Why does the Western US always have to deal with Strong High Pressure Ridges most of the year?

[Djames9]

Originally Posted by alexei27

Theres a couple of things going on.

Much of the west is at high elevations. The Great Basin has big mountains...but even the valleys are at 4000 feet. So...this area really heats up in late spring and early summer. There is not much vegetation to suck up the heat either...so it goes right into the ground...which heats the air near it. This warmer air expands...and you end up with a strong ridge aloft. You can often get low pressure at the surface...but it is a thermal low and has no weather with it.

Also...the jet stream is created by the difference in temperature between the polar regions and the more temperate mid-latitudes. The jet will be wherever the strongest temperature difference is. So...in summer the colder air retreats north...and so does that band of stronger temp change.

Now when the summer ridge sets up over the west...it can effectively block the jet from coming south into the western US. The jet can and often does dive into the central and eastern US however...because there is not this huge mass of hot air in the way :-)

that's a great explanation to this question i asked....=) thanks

That pretty much answers the question

[ColdCanadian]

Originally Posted by alexei27

Now when the summer ridge sets up over the west...it can effectively block the jet from coming south into the western US. The jet can and often does dive into the central and eastern US however...because there is not this huge mass of hot air in the way :-)

Sad, but true.
Our summers average in the 70's and we rarely see 85+ F...
Some summers has no hot weather at all. (90+ F)
Hot weather is definitely uncommon here.

I prefer summer highs at 85+ F...
Too bad wishing for heat can't make a hot air ridge.