Western U.S. Winter Weather Blog

Take a look at the visible satellite. With that huge void of clouds off the coast of California, you might think we are in the middle of summer and undergoing a giant heat wave. Well, the latter is true, kind of. Temperatures through California are trending above normal, like they have for the last few days. So...is winter over for the West?

The current models show the current ridge of high pressure over the West Coast moving eastward towards the Rockies through the weekend. Late in the weekend, a weak low will scoot over Southern California (Figure 1), but this will be a dry system that will bring only possible cooling.

With the standard moist flow in the Northwest being the only appreciable precipitation the next several days, when is the next real storm expected to impact the West?

The GFS is showing that late Monday/Tuesday will be the day. Figure 2 shows the deep trough ready to slam into the West Coast, with the initial wave of precipitation (Figure 3) drawing a ton moisture into the Northwest and Northern California. This precipitation will be mainly rain to begin with because the lower levels will still be quite warm. Look for rain to turn to snow showers through the Cascades and Sierra Nevadas as the cold air moves in. This storm should have some significant inland penetration, so you people in the Intermountain West and Great Basin should expect to see some precipitation. Southern California should also break its dry spell.

This is still a way's out, so lets just see how it pans out!


Figure 1. GFS 500 mb analysis fo Sunday.


Figure 2. GFS 500 mb analysis for Tuesday.


Figure 3. GFS surface analysis for Tuesday.

The Northwest is taking most of the precipitation for the West, allowing the other regions of the West to remain dry.Figure 1 shows the zonal flow that is expected Friday. This will mean continuing rain and high elevation snow for Washington and Oregon.The rest of the West doesn't seem to be getting the message. Warm flow will move into the Southwest from Mexico (Figure 2). This will mean warm temperatures for Arizona and New Mexico as wel as parts of Nevada, Uta...