It's going to get very cold this weekend. The reason is interestinggiant weather patterns the size of our entire country combining together in a unique way.The two most important patterns impacting us now are the Arctic Oscillationor A-O, and the Pacific North-American Oscillation often shortened to the PNA. The technical name for these patterns is called a teleconnectionif you want to impress the weather enthusiast friends in your life. The A-O shifts high and low pressure between the North Pole and Canada. When high pressure moves over the Arctic, cold air gets pushed south into the U.S. It's sending us the cold air. The P-N-A shifts high and low pressure between the western U.S. and the Pacific Ocean south of Alaska. When high pressure is centered near Alaska... low pressure often forms over us. And low pressure often brings us storms. The AO has been sending us cold air for a couple of weeks. It'll also send us this weekend's cold blast. The PNA is different though. It didn't matter for the last few weeks, but now it's also joining the party. It's going to bring low pressure to Colorado this weekend. It's the combination of the cold air and low pressurethat are leading to the near record cold and storm potential here. That is what is making this weekend's cold event so potent. This is a setup we don't see every year. Here's a look at the coldest low temperature in Colorado Springs in the last 30 years. Only in 11 years was the coldest low below negative 10... as forecast this weekend. So on average we only get this cold every three years. I've got more breakdowns of the data in the article on our website.So that's the science: massive weather patterns the size of our entire country - and that change on the scale of weeks to months - happen to be aligning perfectly to drive the cold and snow this weekend. ____Have a question or story idea you would like the First Alert 5 Weather team to consider? Email: [email protected] KOAA News5 on your time, anytime with our free streaming app available for your Roku, FireTV, AppleTV and Android TV. Just search KOAA News5, download and start watching.