JACKSONVILLE, FLA – The year began by plunging the First Coast into multiple freezes with an Arctic Blast that buried the eastern U.S. with snow and frigid air. Yet the situation on the West Coast is jarring: raging wildfires.
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The extreme contrast underscored just how complex and unpredictable weather can be.
What’s Behind the Weather Divide?
The jet stream is the big player here.
This fast-moving air current high above us separates cold polar air from warmer tropical air. Normally, it flows fairly straight, but sometimes it develops a wavy pattern, called meridional flow. That’s when things get interesting — and extreme.
The jet stream has dipped dramatically over the eastern U.S., pulling Arctic air deep into the South the first week of January. Jacksonville has shivered under four freezes to start the year with a blanket of snow as close as North Carolina.
Meanwhile, out west, the jet stream arched upward, creating a ridge that trapped warm, dry weather over California. This pattern, combined with strong Santa Ana winds, set the stage for wildfires. In the Palisades, where rainfall has been scarce for months, dry conditions and gusty winds turned the region into a tinderbox. Fires spread quickly, threatening homes and wildlife.
How Global Patterns Shape Local Weather
These extreme differences across the country aren’t just random. They’re often linked to teleconnections, atmospheric patterns that connect weather across the globe. This winter’s El Niño has been a big influence, strengthening the ridge over the west and deepening the trough over the east.
These large dips and swings in the jet stream get exaggerated paradoxically by global warming resulting in larger weather extremes.
Why the Santa Ana Winds Matter
Santa Ana winds are infamous in California for making bad fire conditions even worse. These dry, gusty winds blow from inland areas toward the coast, sucking moisture out of the air and fueling wildfires.
Wind gusts topped 50 mph, fanning flames and making firefighting incredibly tough. Add the persistent dry conditions from the high-pressure ridge, and you’ve got a perfect recipe for disaster.