Major winter storm to hit Northern Rockies, especially Montana

A major winter storm will hit the Northern Rockies this weekend, dumping more than four feet of snow with wind gusts up to 60 mph.

On Friday there were nearly 70 reports of severe weather from Kansas to Indiana, including more than 50 reports of damaging winds. Wind gusts of 70 mph were reported in Peoria, Illinois, along with tennis-ball-size hail up to 2.5" in diameter.

Strong winds from thunderstorms blew over tents at a Manteno, Illinois, Oktoberfest event, but there were no injuries reported. ABC's Chicago station reported that four people had to be rescued from Lake Michigan in Chicago during the storms Friday night.

Flooding was reported in and around Peoria, Illinois, and more than six inches of rain is estimated to have fallen in northwest Indiana, where flooding is being reported this morning.

Thunderstorms have been firing along a frontal boundary that is moving through parts of the Midwest this morning. Storms will settle down through the morning hours, and attention immediately turns to a major winter storm developing in the Northern Rockies. There are winter storm watches and warnings as well as winter weather advisories for parts of the region through the weekend.

A low pressure system will deepen in the Rockies today and begin to drag cold air from Canada into the western U.S.

Snow will begin to expand in coverage across Montana and northern Idaho this morning and afternoon. Out ahead of the low pressure, some severe storms could develop in Kansas and western Missouri, where strong winds and large yet brief tornadoes will be possible.

The low pressure will deepen Saturday evening and early Sunday with heavy snow spreading across the Northern Rockies and parts of the High Plains -- especially in the state of Montana. Winds could gust as high as 60 mph in parts of Montana today, which could cause tree and power line damage. Wind gusts of this strength could last the entire weekend.

Meanwhile, some strong storms, with lightning, heavy rain and gusty winds will be possible across parts of the Midwest on Sunday, where 1-2 inches of additional rainfall is possible.

More than four feet of snow will be possible through the end of the weekend in the highest elevations of Montana. However, a widespread 6-12 inches is possible across much of the northern and central parts of the state.

The National Weather Service says this heavy snow over Montana could potentially be a historic winter storm. Travel will be very dangerous across parts of the state due to the heavy snow and winds.

Lastly, cold air behind the storm will help bring some snow to the mountain passes from Washington to California, which could cause some travel delays and reduced visibility. Up to a foot of snow is possible in the Sierra Nevada's highest peaks. This could be potentially dangerous for those traveling in the mountains this weekend.