Freeze warnings have been issued for southern California as Los Angeles and San Diego are expected to see their lowest temperatures in years.
A deep dip in the jet stream across the western United States is helping to usher in a very cold polar air mass from Canada.
For downtown Los Angeles, residents have been warned that the mercury reading on their thermometers could dip down to as low as 1-2C. This is about 8 degrees lower than they would normally see this at time of year.
California’s most southerly major city is expecting even lower temperatures than that. San Diego which tends to have a very constant climate, was expecting frost on the lawns and cars as temperatures were expected to be as low as 0C.
At world renowned San Diego Zoo the heaters were brought out in order to keep many of its residents warm.
Homeless shelters in central California were also beefing up efforts to protect people on the streets from the freezing temperatures by handing out extra clothes and blankets.
Farmers in the state’s central San Joaquin Valley have been busy scrambling to protect their fragile citrus crops. By running wind machines and water to protect their fruit, they can raise the temperature in the groves by up to 2 degrees, just enough to keep the harvest from freezing.
Meanwhile on the other side of the US the opposite effect is happening here. The jet stream is making its way up from the south, right along the eastern seaboard.
From Atlanta to Boston, temperatures on Sunday were expected to be 10-12 degrees higher than average. Unlike their fellow Americans in California who will get to enjoy the sun, those warmer temperatures will be accompanied by very dense fog.
Driving conditions are expected to be diminished drastically by low visibility. Right across the east coast major airports are likely to see significant delays or cancellations.
The weather is expected to be much of the same for both coasts until Monday, and then conditions are then expected to return back to normal by the time we get to mid-week.