New research shows atmospheric moisture helps explain why some extreme weather events, like heat waves and floods, last longer than expected.

The large-scale weather pattern that's now influencing much of the USA's weather – known as an omega block because of its resemblance to the Greek letter omega – isn't budging right now.

For several days, the weather pattern over the U.S. will become blocked and slow. That means soaking, possibly flooding rain in the South and also where rain is needed in the Northeast.

An “ omega block ” weather pattern is forecast to set up across the country this weekend, possibly bringing some May snow. Here's what it will mean for you. The Weather Channel is forecasting ...

An “omega block” weather pattern is forecast to set up across the country this weekend, possibly bringing some May snow. Here's what it will mean for you. The Weather Channel is forecasting a ...