VAWS: What is an Atmospheric River and how do Alaska National Weather Service forecasters monitor these impactful events on communities and the hydrologic cycle?

Virtual Alaska Weather Symposium

Speakers: Aaron Jacobs, NWS Juneau, and Martin Ralph, Scripps Institution of Oceanography

Atmospheric rivers (ARs) have the ability to transport large amounts of water vapor from the tropics poleward into the upper latitudes that can have positive and negative effects on the environment and society. For example, ARs events can cause dangerous flooding, debris flows and large amounts of snowfall but at the same time can be beneficial to the environment especially areas that are in a drought. 20+ years of research have increased our understating of the dynamics of ARs.

At the same time the improved remote sensing and better numerical weather prediction has given forecasters increased ability to monitor atmospheric rivers, although forecast challenges associated with ARs remain.

This talk will review what we know of ARs, how forecasters monitor these events, what type of impacts they can have on communities of Alaska, and ongoing research particular to Alaska.