A cold low pressure center to our north will keep us under a dome of very chilly temperatures through the weekend, with a warming trend coming our way early next week. Variable amounts of cloudiness will come and go through the weekend, but thanks to an offshore ridge of high pressure it is unlikely they will produce any showers before the work week begins. The ridge gets undercut next week, allowing a series of storms to punch through and get us back into an active storm pattern through Friday.
So why should cold weather on the east coast result in warm weather here? First take a look at how the wind flows around the globe at our latitudes. Even though it takes a generally west to east direction, it wiggles north and south on its way in a series of waves, dipping south under the lows, and climbing north over the highs. Typically, there are 4 or 5 of these pairs, or “couplets”, of waves going around the earth at any one time. Watch the next time you see a satellite picture and you will probably see one of these couplets.
The upshot of all this is if you have cold air plunging into the eastern half of the country, digging a deep low, you will also pump up a strong high on either side of it, leaving us high and dry (and warm) here in the west. The stronger the eastern low, the stronger the western high.
The same concept works for precipitation. Lows bring rain and snow (notice no one was complaining about a drought in the east last winter), and highs bring generally dry weather. So it’s rare to see a persistent drought on both coasts at the same time, just like it’s rare that you will have two big winters on each.
Can you give the 7 day forecast for Tahoe as well as Reno on the 5 o’clock news please.