Southern California had an incredibly rough start to winter last year when a series of monster storm systems brought epic rain and flooding. December 2010 became one of the wettest Decembers on record for Los Angeles with nearly a year's worth of rain falling in just one month.
While a few heavy rain events cannot be completely ruled out in Los Angeles and San Diego this year, the focus of stormy weather this winter is predicted to be farther north, according to the AccuWeather.com Long-Range Forecasting Team.
Overall, this winter is expected to be fairly typical in Southern California with near-normal rainfall and temperatures. However, it may be a long stretch toward the end for people who become anxious for spring, as unusually chilly conditions will take hold in February.
The Pineapple Express: A Key Winter Player for California
It was the famed "Pineapple Express," a phenomenon that occurs when a strong, persistent flow of tropical moisture sets up from the Hawaiian Islands to the West Coast of the U.S., that brought the historic storms to Southern California in December 2010. More than 10 inches of rain fell last December in Los Angeles, a city that typically receives a little less than 15 inches of rain in an entire year.
The Pineapple Express could develop for a time again this winter, though it would most likely be aimed at northern and central California.
"Last year, California was hit hard when the Pineapple Express set up from Dec. 17-22, producing massive flooding and 13 feet of snow in the Sierra," explained Paul Pastelok, AccuWeather.com Expert Long-Range Meteorologist and leader of the Long-Range Forecasting Team. "The Pineapple Express could develop for a period this winter and take aim at northern and central California. That could lead to monster snowfall and heavy valley rain with the risk of flooding and mudslides."
Must Be Careful with La Niñas
La Niña, a phenomenon that occurs when sea surface temperatures across the equatorial central and eastern Pacific are below normal, has a strong influence on the jet stream and weather patterns, including the Pineapple Express, that set up across the United States.
The general trend for La Niña winters is for Southern California to be drier than normal with above-average temperatures. However, as evidenced by last year's record-shattering December storms, there can be exceptions.
"While a La Niña like the one we are expecting this winter typically brings lower-than-normal precipitation to Southern California and the Southwest, the concern this year is that something similar to what happened last year could happen again," stated AccuWeather.com Senior Meteorologist and Western Expert Ken Clark. "Storms may be far enough south or wet enough that rainfall could be higher than what is typically expected during a La Niña."
In general, the Long-Range Forecasting Team expects December to be fairly typical for Southern California with near-normal precipitation and near- to slightly above-normal temperatures. January is forecast to turn out drier than usual, though temperatures will overall remain near normal.
From late January into February, however, a transition to chillier weather is predicted to take place, as the overall jet stream pattern over the West Coast undergoes some major changes. Precipitation in February is likely to be near to slightly below normal.
Winter is California's wettest season. For Los Angeles and San Diego, February is usually the wettest month of the year with January being a close second.
Following a blustery and chilly weekend, temperatures will once again take a tumble across the northeastern United States during the first half of this week.
Several storms will bring periods of rain and gusty winds to the west coast of the United States this week, and Southern California will not be excluded from rainfall this time.
A strengthening tropical cyclone will unleash heavy rain and strong winds on areas from western Myanmar to northeast India and Bangladesh this week.
Flooding downpours and thunderstorms will target a part of the central United States at midweek.
Dry weather set to dominate the southern United States into November will only worsen the already extreme drought conditions.
The changing of the seasons will bring beneficial rainfall to northern Brazil, a region that has experienced severe drought over the past several years.
Newbury, VT (1843)
12 inches of snow.
East Coast, USA (1878)
"Gale of '78;" hurricane center over Richmond, VA. Washington, DC. barometer reading of 28.78"/975 mb. Cape May had winds of 84 mph from the SE. Highest tide ever for the Delaware River. Winds 100 mph at Wilmington, DE. Severe damage in Philadelphia.
Off British Columbia Coast (1918)
The Princess Sophia struck a coastal reef in severe storm and sank. All 343 aboard drowned.