A strengthening La Niña weather pattern has brought cooler temperatures to the world — except in California, where it is expected to be dry and warm for the next three months.
Weather.com is projecting that the huge Canadian Arctic air mass that is currently over parts of the Midwest, South and East, will be followed by another “reinforcing shot” of bitterly cold air during the latter half of the week ahead. With record wind chills of -50 to -60 degrees below zero recorded in the Dakotas and northern Minnesota, single-digit temperatures will continue to stretch as far south as Alabama and Georgia.
La Niña is an extreme version of the normal Pacific Ocean winds that circle clockwise, bringing warm water from Polynesia to Japan and then circling down south cold water from Alaska. This year’s weather pattern follows last year’s El Niño, which caused a counter-clockwise wind condition that sent Polynesian monsoon rains to hammer the West Coast.
California has been La Niña’s typical island of warmth this year, with temperatures running about 8-to-10 degrees above normal. The huge TV audience for the Rose Bowl that watched Georgia beat Oklahoma to win a shot at the national championship game had to be envious of fans at the packed stadium enjoying the day in shorts and tank tops.
AccuWeather’s Los Angeles forecast for the next 90 days predicts consistently warm winter temperatures, averaging 71-degree highs and 51-degree lows. Total rainfall for the coming period is predicted to be just 4.3 inches, about half the average.
The Great Lakes region could suffer near record 90 percent ice coverage due to the current 37-degree surface temperatures — three degrees colder than average — and triple the “ice build” compared to last year, according to George Leshkevich, a physical scientist at the Great Lakes National Oceanic and Atmospheric Administration (NOAA) Laboratory. The 225-foot Coast Guard Cutter Hollyhock will be dispatched to Lake Erie for ice-breaking later this week, a full month earlier than usual.
Eastern Pacific surface temperatures have averaged 1.5 degrees Fahrenheit below normal. As a result, the clockwise winds are accelerating. NOAA predicts that a 2017-2018 winter La Niña will persist across the Northern Hemisphere. The Pacific Ocean negative temperature peak is expected to reach 3 degrees Fahrenheit by mid-to-late spring.
NOAA projects La Niña’s temperature and precipitation across the United States for the upcoming months favor “above-average temperatures and below-median precipitation across the southern tier of the United States, and below-average temperatures and above-median precipitation across the northern tier of the United States.”
Despite California’s expected warm temperatures and low rainfall, Fresno County Farm Bureau CEO Ryan Jacobsen told the Fresno Bee that lack of rain may not be a big issue for farmers, given last year’s massive rains and record snow pack. All but two of California’s reservoir levels are currently over 100 percent of the historical average. Only Lake Oroville is at 57 percent full, due to construction to repair its spillway and infrastructure.
The California Department of Water Resources (DWR) expressed substantial concerns regarding the potential for mudslides in areas devastated by the three big California wildfires. But a modest La Niña rain season could reduce the risk of flash floods and mudslides this spring. The DWR is still advising residents in vulnerable areas to take precautions that include using sandbags and hay bales around their homes.