How to prepare for "rare," "dangerous" ice expected from this weekend's storm

Here's what to expect about ice, snow, and freezing rain this weekend:

The latest forecast on the winter storm

Driving the news: "Snowfall totals exceeding 12 inches are likely across the Ohio Valley, Mid-Atlantic, and Northeast," National Weather Service forecasters said on Friday.

• "In addition, widespread freezing rain and sleet are expected across the Southern Plains, the Lower Mississippi Valley, the Tennessee Valley, and the Southeast."
• Over a dozen governors have declared states of emergency and thousands of flights have been canceled ahead of this weekend's storm.

What they're saying: "Historically speaking, this storm is forecast to be on the higher end for impacts from both ice and snow," Eric Guillot, a scientist at the weather service, said.

• Andrew Kruczkiewicz, a meteorologist at Columbia University's National Center for Disaster Preparedness, said that areas like Arizona and Texas should be especially cautious this weekend.
• The storm is likely to hit "communities that rarely see this type of precipitation," he said, or that "will be seeing it for the first time."

What to know about snow, ice, freezing rain

Context: Freezing rain poses the biggest danger this weekend, experts said.

• Snow is "frozen ice crystals that fall as precipitation," but "freezing rain is liquid precipitation that falls through a very shallow cold layer at the ground and does not have time to freeze until it makes contact with the surface," Guillot explained.

How it works: That means the rain "freezes on and around surfaces," Kruczkiewicz told Axios.

• "That's important, because when the rain lands, not only is the air at the surface below freezing, but many times the surfaces themselves are below freezing."
• That could mean "cars encapsulated in ice," and "very importantly, bridges and roadways," he said.
• Sleet, in contrast, he said, "is like popcorn seeds" and "doesn't accumulate."

Guillot warned "Ice storms, specifically freezing rain, carry with them the risk of widespread power outages due to the weight of the ice on trees and power lines."

• "With this storm, the arctic air mass behind it will ensure this ice will not melt for several days, which may make it difficult for utility crews to restore power in a timely manner," he said.
• "It's important to prepare for such a scenario if you are in an area with high amounts of ice forecasted."

State of play: Kruczkiewicz said freezing rain is "by far the most dangerous" form of precipitation.

• He advised staying off the road entirely in freezing rain, but said to be wary if you're driving and you notice raindrops with the temperature below zero.
• "Sometimes, you can see the ice, sometimes you can't... the ice can accumulate and the slight differences in elevation along a roadway can be like frozen over puddles that are dangerous for driving."

How to prepare for the storm

Threat level: The NWS forecasters on Friday warned that the precipitation and cold will have "prolonged hazardous travel and infrastructure impacts."

• "The storm will cause significant to locally catastrophic ice accumulations with the potential for long-duration power outages, extensive tree damage, and extremely dangerous or impassable travel conditions," they said.

Guillot suggested people take the following steps to prepare:

• Put together a home emergency kit which includes adequate clothing and blankets, enough ready-to-eat food to last three days, three gallons of drinking water per person, a NOAA Weather Radio, a first aid kit, extra batteries and flashlights, a manual can opener, a cell phone charger, and any medications you may need.
• Ensure you are stocked up on these other winter supplies: rock salt or ice melt, sand to improve traction, snow shovels or other snow removal equipment, and sufficient heating fuel.
• Traveling is not recommended, Guillot said, but if you must do so, make sure you have an emergency kit in your vehicle which includes: a survival blanket, road salt, a shovel, a scraper, jumper cables, drinking water, a repair kit, a flashlight and flares.

He also advised preparatory maintenance.

• Perform routine yard maintenance and be cognizant of your surroundings: "Trim weak or damaged branches around your home" and "don't park you car underneath trees."
• Perform routine indoor maintenance, which includes checking smoke and carbon monoxide detectors.

Keep in mind: Water is more likely to freeze in pipes and burst from pressure when temperatures drop.

• To prevent this, faucets should be left dripping to keep the water moving, according to the American Red Cross.
• You should also disconnect hoses and cover outdoor spigots with insulated faucet covers, plumbers told CBS News.