California is bracing for a potentially historic deluge as a series of atmospheric rivers are forecast to dump torrential rain across the state through Friday, following weeks of devastating flooding in the Pacific Northwest.
California Flood Watch: Atmospheric Rivers Threaten Record Rainfall
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A relentless series of storms is poised to deliver significant rainfall, raising concerns about widespread flooding and hazardous conditions.
- Northern California could see rainfall totals of 200-300mm (8-12in) by Boxing Day.
- Los Angeles may experience one of its wettest Christmases on record, with 100-150mm (4-6in) of rain expected between Christmas Eve and Christmas Day.
- Yosemite National Park is under winter storm warnings, anticipating 1.8-2.4 metres (6-8ft) of snow accumulation by Boxing Day.
- Zimbabwe is facing heavy rain, lightning, and strong winds leading up to Christmas, with a level 2 weather warning in effect.
- Sydney, Australia, will see a dramatic temperature drop from above 40C to around 22C by Christmas Day.
Already, 50-75mm (2-3in) of rainfall has been recorded across northern California this weekend, and the onslaught is far from over. These atmospheric rivers—long, concentrated bands of moisture in the atmosphere—will continue to bring periods of heavy rain and mountain snow to the northern and central parts of the state.
What exactly *is* an atmospheric river? These are essentially rivers in the sky, carrying vast amounts of water vapor. When they make landfall, they can unleash intense precipitation, leading to flooding, landslides, and other hazards.
Los Angeles Braces for a Soggy Christmas
The forecast for Los Angeles is particularly concerning. The city could receive 100-150mm (4-6in) of rainfall between December 24th and December 25th, potentially making it one of the wettest Christmases on record. River and urban flooding are likely, especially in areas with runoff from higher elevations, along with increased risks of mudslides and rockslides in mountainous and foothill regions.
Yosemite Faces Heavy Snowfall
Further north, winter storm warnings are in effect for Yosemite National Park. Accumulating snowfall could reach 1.8-2.4 metres (6-8ft) by Boxing Day. Combined with strong winds, these conditions will make travel extremely difficult throughout the festive period.
Global Weather Concerns Extend Beyond the U.S.
The severe weather isn’t limited to the United States. Heavy rain, lightning, and strong winds are forecast across much of Zimbabwe leading up to Christmas. The Meteorological Services Department issued a level 2 weather warning from December 21st to December 24th, anticipating rainfall exceeding 50mm (2in) within a 24-hour period in some areas.
Australia is experiencing a dramatic temperature swing. Sydney, currently above 40C, is expected to cool to around 22C by Christmas Day—approximately 5C below average for this time of year. Perth, conversely, will see temperatures climb, peaking around 40C around Christmas Day, about 10C above average.
