Wet west, plains storm to come.

The dry weather the western United States has enjoyed has come to an abrupt end. Three storm system will plow into the Pacific Northwest and northern California over the next 5 days, likely leading to flash flooding and significant snows in the highest elevations. Currently the 1000-500 mb thickness values do not support snowfall, even in the Sierras, but this will change by the 2nd, and definitely the 3rd system. With SEVEN inches of liquid equivalent precipitation forecast for the Sierras by the HPC, I wouldn't be surprised to see feet of snow pile up in the highest points of the Sierras.

On top of this, wind gusts to 50 mph look possible tonight in southern California into the Sierras, and could be even stronger in the mountains from the next two storms. 500 mb winds of 80-90 knots will interact with the mountains peaks and passes, likely bringing gusts to 65 mph...or higher!

And when this third system finally plows in, the fun begins in the intermountain west and then the plains states. By day 7 a significant vort max and longwave trough will have moved into the plains, becoming negatively tilted, leading to the risk of a severe weather event. Currently the environment looks marginal, however if moisture can return sufficiently and the mid-lat low doesn't occlude too quickly, we could be in store for a classic fall severe weather event. We will have to watch this over the next 5-6 days to see whats in store. One good thing, winter weather doesn't look like a strong bet with this system, at least in the great plains. Snow will likely occur in the mountains and possibly Montana/North Dakota through day 7, but big snow storm doesn't currently look in the cards.

And then there is the LONG RANGE. The Arctic Oscillation is currently starting its dive to negative, likely beginning the trend towards colder weather in the eastern United States. Even through the models aren't currently showing it, I wouldn't be surprised to see a shift in the models for the period from Nov 10-20th. I think a cold shot is in the making. But we shall see. The Arctic Oscillation isn't always 100% right, but it is a very good indication.