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Atmospheric river bringing beneficial rain to San Diego

Posted at 5:43 PM, Mar 25, 2022
and last updated 2022-03-25 20:43:33-04

SAN DIEGO, Calif. (KGTV) - An atmospheric river is heading toward San Diego, bringing much-needed rain to the region.

San Diego is currently in a deficit of about three inches for the water year, which began October 1.

Atmospheric rivers are crucial for west coast rain totals. The moisture-driven storms can provide up to 50% of annual rainfall for the San Diego region and can be beneficial, but also have the potential to be dangerous if too much rain falls.

“Atmospheric rivers are storms that start over the ocean and release elongated plumes of water, so the name really fits it really well, rivers in the sky,” said Scripps Institution of Oceanography and Center for Western Weather and Water Extremes climatologist Julie Kalansky.

Kalansky said that after a mostly dry 2022, this rain will be beneficial, although this is a weaker atmospheric river event. This storm is ranked as a category 1 on a new scale just launched in 2019.

The new categorical scale was developed by Scripps Institution of Oceanography researchers. It ranks storms on a scale between 1 and 5, with 1 being the weakest. Categories 1-2 are considered beneficial rain because rain totals will not be torrential. Starting around category 3 and into 4 and 5 turns potentially hazardous because high rain totals can lead to flooding.

In addition to growing categories with the hope of increasing understanding of these storms, researchers are hoping to gain more information about atmospheric rivers by flying into the sky and gathering measurements. The Atmospheric River Reconnaissance is a collaboration between multiple agencies.

In 2022, the recon team expanded from ten to 13 weeks of flights, with a goal of continuing to grow the project.

“What we know from the data that satellites and other instruments collect is there’s a void, especially in atmospheric rivers because they’re very cloudy, so by having this data helps improve the forecast,” said Kalansky.