DENVER -- Bitter cold and snow will continue to take aim at Colorado this week, with significant changes arriving Thursday.

One positive note if you have travel plans for Thursday is that the storm has slowed down about 10 hours from original forecasts. There will be increasing clouds and wind by the noon hour, but the precipitation should hold off until the evening hours -- good news for those with flight plans out of Denver.

But if you have a late afternoon or evening flight Thursday, our best advice is to monitor the latest forecast details. As an alternate plan, you might consider heading to the airport early just in case you need to go stand-by on an earlier flight.

Weather Synopsis

A large, slow-moving winter storm will move into Washington Tuesday night. The trough of low pressure will dig into the western United States by Thursday.

Ahead of the storm, moisture will increase across Colorado. At the same time, cold air will move south from Canada.

These two elements, combined with the eventual track of the slow-moving low pressure system, will combine to bring an extended period of unsettled weather to the state.

So how much snow will we see?

This remains a very tough forecast, and will ultimately depend on the exact track of the storm.

There is still strong potential for at least 6 inches of snow in Denver and on the eastern plains, with up to a foot in the mountains and foothills. Amounts in the 3 to 6 inch range look likely on the eastern plains.

There is a chance that the precipitation will start as freezing drizzle or sleet from Denver east to Kansas late Thursday. That would create tough driving conditions on the roads, especially once the precipitation changes to snow and accumulates.

"The cold front has slowed down just a little -- about 6 to 10 hours," said 7NEWS Chief Meteorologist Mike Nelson. "But the colder weather is still on track."

Snow accumulations are always tough to forecast when you have falling temperatures. The air temperature plays a key role in the development of snow crystals.

When temperatures are between 3 and 14 degrees, you get the best conditions for maximizing the growth of snow crystals.

In warmer snowstorms, with temperatures in the 20s, an inch of water usually results in about 10 inches of snow. With temperatures between 3 and 14 degrees, an inch of water can yield 15 to as much as 30 inches of snow.

How cold will it be and how long will it last?

Click here for historical facts of cold January weather in Denver.

By the weekend and early next week, forecast highs will likely only be in the single digits for Denver and the eastern plains. There remains the possibility that highs may struggle to climb above 0 degrees in Denver once to core of the coldest air arrives.

Overnight lows will be well below zero over the weekend into early next week.

"This will likely be the most dangerous part of this storm system," said Nelson. "We will fall below the freezing mark by Thursday afternoon and could remain there for the next seven days -- with most nights at or below zero."

Click here for tips on how to stay warm during the upcoming winter blast.

What do I do if I have travel plans?

Travel conditions are expected to deteriorate during the evening hours on Thursday, both in the mountains, on the plains and across the urban corridor. States surrounding Colorado are also forecasting a prolonged period of winter weather.

Click here and bookmark this page for links to airlines, road conditions in Colorado and surrounding states, and more.

The meteorologists of 7NEWS are busy analyzing the latest information on the approaching storm. Stay with 7NEWS and TheDenverChannel.com for the latest forecast over the next few days.

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