What is an atmospheric river, and does it help bring Houston rain?

HOUSTON, Texas (KTRK) -- Since the beginning of the month, portions of Washington State have seen almost nine inches of rain from an atmospheric river event, three times more rain than they typically see in early December.

By definition, atmospheric rivers are relatively narrow regions in the atmosphere that are responsible for most of the transport of water vapor from the tropics. This is typically seen with West Coast weather, where a strong jet stream can usher in lots of moisture from the Pacific Ocean, falling as heavy rain or snow. What is tricky about atmospheric rivers is that they can linger for days, which leads to flood events and even landslides.

So, if you've never heard of an atmospheric river before while living in southeast Texas, it's because the region doesn't really see it. However, the same jet stream pattern that brings heavy rain to the West Coast can sometimes shape and help bring us our own rain, which is what could happen later this week.

The same jet stream flow that brought the heavy rain to the Pacific Northwest last week will dip into the desert southwest this week, creating an upper-level low. Then, that upper-level low could help send some rain our way later this week. While we're not going to see an atmospheric river, there is an indirect correlation. You could say this is just another example of how the weather across the country is connected. But these weather systems always evolve, and so do the impacts.

As of Monday, the ABC13 weather team has been keeping a close eye on this next weather system. There is the chance portions of southeast Texas could receive some heavy rain Friday, but it's a bit too early to forewarn of any potential flooding. There is a 60% chance for showers and storms, though, on Friday.