What is freezing rain? FOX 12 meteorologist explains - KPTV - FOX 12

What is freezing rain? FOX 12 meteorologist explains

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The forecast is calling for snow and freezing rain this weekend in the Portland metro area and Willamette Valley.

If you’re wondering what freezing rain is, here’s an explanation:

Precipitation starts as snow in clouds in the upper levels of the atmosphere. Up there, it is below freezing (32 degrees Fahrenheit). In a snow situation, all levels of the atmosphere from the clouds to the ground need to be at or below freezing.

In a freezing rain event, the snow falls from the clouds through an above freezing layer (warmer than 32 degrees Fahrenheit) and completely melts into rain. That raindrop then stays liquid as it enters another below freezing air mass near the surface. The below freezing liquid is called supercooled water. The rain then freezes to anything it touches, creating an icy glaze.

Major ice storms are rare in the metro area, but we’ve had some big ones in the past 25 years.

In 1996, an ice and snow storm took out power lines and closed I-84. Farther east of the metro area - along I-84 - a snow and mudslide blocked the freeway.

In 2004, an expected one day snow and ice storm turned into a four day ordeal for the area. The Portland International Airport was closed for two days for the first time in its history. Blizzard warnings were issued for the eastern parts of the metro area, as winds gusted over 70 mph with blowing snow. Over 1 inch of freezing rain fell in some spots, even as far west as the coastline.

For the latest weather forecast from the FOX 12 Weather team, as well as the latest traffic updates and closings information, download our free FOX 12 Weather App for iPhone and for Android.

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