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Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

According to the American Meteorological Society Glossary of Meteorology, a heat burst is a "localized, sudden increase in surface temperature associated with a thunderstorm, shower, or mesoscale convective system, often accompanied by extreme drying."

Indeed, several Mesonet weather stations just northwest of Mobridge, SD (including the Mahto SDSU and McLaughlin+Trail City RWIS stations) recorded sudden increases in temperature and decreases in humidity, along with spikes in wind gusts from 10 pm Friday to 1 am Saturday morning. Notably, the Mahto station rose ~15 degrees in 20 minutes peaking at 96 degrees at 11 pm, and gusted to 62 mph just before at 10:55 pm. Showers falling into the right environment led to this fairly rare phenomenon. See the slides below for more details.