The first significant snow event of the season will definitely be memorable across the northern Rockies. Snow has already commenced, with more set to fall through the weekend. The heaviest will come down Saturday with the passage of a potent storm. Saturday night, cold rain over the northern High Plains will change to accumulating snow.

A large portion of the northern Rockies, as well as the Black Hills of South Dakota, will receive 6 to 12 inches of snow through the weekend. Amounts will exceed a foot in Billings, Mont., where snow has been coming down hard since Thursday night. The mountains of northwestern Wyoming, however, will top the storm's totals. A yardstick will be needed to measure that snow.

The snow is piling up in Montana as the first major winter storm of the season moves across the northern Rockies. It will be cold and windy behind the storm and warm and wonderful ahead of it.

The core of the storm today will move from Utah into the northern Rockies;  however, the snow has been falling since Thursday across much of southern Montana.

The Severe Weather Center lists the winter storm watches and warnings in effect across the northern Rockies.

The West Regional News story reports that the storm through Sunday will dump heavy snow from Utah to the western Dakotas.

As much as 3 feet is forecast in the Tetons in northwestern Wyoming. Billings, Mont., could get more than a foot, while lesser amounts are forecast in southeastern Montana and the Black Hills. 


The heavy snow could accumulate on trees that still have their leaves. Downed trees and power lines this weekend could lead to power outages.

The storm will have wide-reaching effects on the weather across the country this weekend, allowing cold air to flow into Southern California he pumping unseasonably warm air into the Midwest and the East.

A significant dip in the jet stream behind the storm has allowed cold air to push as far south as Southern California. The switch from an offshore flow earlier in the week to an onshore flow this weekend has resulted in a 10 to 20 degree drop in high temperatures.

On Wednesday, San Diego broke a daily temperature record that had stood since 1899 when the high reached 94 degrees. On Thursday, the high was 70 degrees, five degrees below normal.

The plunging jet stream and the flow around the storm has produced strong winds that today will blast across the Desert Southwest. Wind advisories and watches are in effect from California to New Mexico.

The strongest winds will be in the mountain passes and canyons in Southern California, as well as in the High Desert in Nevada and Arizona.

Winds gusting as high as 60 to 80 mph will create dust storms and dangerous cross winds that will lead to treacherous driving conditions,  especially in the "Grapevine" section of Interstate 5 in California's Central Valley.

By Sunday, Hurricane Norbert will add to the mix of nasty weather in the West.  Norbert should weakened to Category 1 strength overnight as it moved over cooler water in the eastern Pacific Ocean.

The storm will make landfall early Saturday morning along the southern Baja California peninsula, likely near Puerto San Carlos.


Much of the moisture will dissipate over the Mexican mountains;  however, there will be enough to fuel strong thunderstorms and the potential for localized flash flooding on the southern and central Plains.

Conditions in the Midwest and East this weekend will be 180 degrees different than the nasty conditions in the West. It will feel more like summer than fall from the central Plains to New England as high pressure dominates and the storm in the West helps to pump warm air from the Southwest into the Northeast.

The high pressure and the air mass over the region will produce cool nights and warm days, with the only potential problem expected to be morning fog in river valleys and some interior areas across the Northeast. 



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