West Coast Fall Forecast

Autumn is known for its shorter days, colorful leafy landscapes and cool, crisp nights, but Americans looking forward to these fall staples may need to wait a little longer this year as summer lingers across much of the United States.

The autumnal equinox will mark the official changing of the seasons with fall already having kicked off on September 22^nd. Meterologists at AccuWeather have analyzing global weather patterns and different forecasting tools to paint a picture of what weather will unfold across the U.S. in the coming months.

One big factor being taken into consideration for the 2020 U.S. fall forecast is the development of La Niña. This is a phenomenon in which the ocean near the equator of the Pacific Ocean is cooler than normal, a change that can influence the global weather pattern. Even with the changing of the seasons, it may still feel like summer for many across the U.S. as warm weather holds strong over much of the country.

October will be a major turning point in the season for temperatures in the central and northwestern U.S., while residents near the Atlantic and Gulf coasts remain vigilant amid a very active hurricane season. “The heat waves that we’ve seen that have been very impressive over the summer season are going to linger.” This could mean more 90-degree days for cities that have roasted in the summer heat.

“A good portion of the fall season is going to be be beneficial to the workers that work outside and have more projects that have to get done and finished because, remember, they started out late due to COVID-19.”

Residents across the West Coast will face an elevated risk of wildfires heading into the new season, but the fire danger will be short-lived for part of the region. “This year, we are going to have an early-fall wildfire season in the Pacific Northwest.”

The active start to the wildfire season will last for only a few weeks before a wet pattern begins to set in by late October, helping to put a lid on the larger fires that ignite in September and to shorten the overall length of the fire season.

“Definitely look for a shorter wildfire season in the Northwest, but still a strong one from places like eastern Washington, Oregon down into Northern California.”

Meanwhile, farther south in California, it will take a longer time for the onset of the rainy season to arrive with storms being few and far between until the tail end of autumn and early winter. As a result, the fire season in Central and Southern California will last longer than it will in the Pacific Northwest.

October, in particular, is forecast to bring several Santa Ana Wind events, making it the busiest time for wildfires in Southern California. Similar to tropical storms impacting the East Coast, the upcoming wildfire season in the West could look different due to the coronavirus pandemic. In addition to complicating plans for evacuation shelters, air pollution caused by wildfires could potentially increase the likelihood of being infected with COVID-19, The San Diego Union-Tribune reported.

Any air pollution from wildfire smoke could heighten people’s chances of becoming infected with the coronavirus, Mary Prunicki, a senior research scientist at Stanford’s Parker Center for Allergy and Asthma Research, told The San Diego Tribune. Prunicki also cautioned that studies have shown that heavy wildfire smoke can also exacerbate flu season, which typically begins in October.

Californians may also face rounds of power shutoffs on days with extreme fire danger, a tactic used by power companies in 2019 to lower the chances of new fires sparking. These outages could significantly disrupt those that are telecommuting for work due to COVID-19.

Wet weather is not projected to return to Central and Southern California on a more regular basis until the end of autumn and early winter, eventually marking an end to the wildfire season. The prolonged dry pattern could be to the benefit of those that had plans to travel to national parks across the state earlier in the year but ultimately had to postpone their trips due to COVID-19.

On the flip side of the coin, the late arrival of meaningful storms will delay the onset of snow for ski resorts across California, especially those in the southern Sierra as well as the San Gabriel and San Bernardino mountains.