美国有线新闻 CNN 炸弹气旋袭击美国 美加相继停飞波音737 Max 8（在线收听）

CARL AZUZ, CNN 10 ANCHOR: A bomb cyclone has just dropped on the U.S. heartland. What that is and what it does is our first topic this Thursday on CNN 10. I'm Carl Azuz. Thank you for watching.

In the capital of Colorado, the Mile High City of Denver, Tuesday's high temperature was nearly 60 degrees Fahrenheit. Twenty-four hours later, it was freezing and snowing.

This is the result of bombogenesis, what's also called a bomb cyclone. It happens when there's a rapid drop in atmospheric pressure that causes a storm to become very intense, very quickly. How intense?

Central and Northern U.S. states that lie in the Rocky Mountains and east of them were bracing for winds that could reach 70 miles per hour. That's nearly the speed of a category one hurricane.

Blizzard and winter storm warnings were in effect for parts of Colorado, Nebraska, South Dakota and Wyoming. Heavy snow was likely. The National Weather Service in Boulder, Colorado, predicted whiteout conditions when there's no visibility and power outages, too.

It told the people in the region to cancel any travel plans Wednesday afternoon and evening. Some folks didn't have a choice. More than a thousand flights were cancelled yesterday, mostly at Denver International Airport.

Denver public schools like several other districts in Colorado were closed. Forecasters expected the storm to move northeast from the Colorado Rocky Mountains, with the snow tapering off by Thursday afternoon. But they're also on the lookout for strong winds and possible flooding in southern states east of the Rockies, where thunderstorms were likely.

Next today, Boeing passenger planes model 737 MAX 8 and 9 have been grounded in the U.S. and Canada. The two nations announced their decision yesterday afternoon. At that point, they've been the only two countries with a substantial number of these planes still flying.

U.S. President Donald Trump said new information about the Ethiopian airlines crash led to the Federal Aviation Administration's order to temporarily ground 737 MAX 8s and 9s.

We cover the plane and the accident in yesterday's show. You can find that at CNN10.com.

The Boeing Company says it still has full confidence in its airplane's safety, but that out of an abundance of caution, it supports the decision by the U.S. government.