I promised several readers last week that I would write about winter.
There is nothing like a heat wave to make you dream of crisp cool winter days and quiet drifts of snow. (Ok, Californians, I know you dream of 72˚ weather and enough rain that you don’t have to water the still blossoming garden.)
If, as most climate experts expect, we have an El Niño, winter might be a bit weird.
Click to expand. Satellite pictures show how El Niños develop. SOURCE: NOAA.
Basically, an El Niño (Spanish for “Little Boy) occurs when the Tropical Pacific is unusually warm, more than 0.5˚C or 0.9˚F hotter than average. It heats the air above it, which allows the atmosphere to hold more moisture. Air pressure changes and that changes wind patterns. The unusual warmth lasts for months. Since the warm area is hundreds of thousands of square miles in size, it usually changes weather around the Pacific Rim and throughout the tropics.
El Niños move. The warmer water drifts east, while new warm water wells up in the center of the Pacific. Eventually the warm water crashes into the west coast of South America, around Ecuador. From there, it drifts north along the West Coast until it is off the coast of California. Warmth shifts north in the West and winds carry it inland. Meanwhile, the Pacific jetstream is shifted north and the southern tier of states wallow in water. (Good news for Texas!)
Click to expand. El Niños bring warmer weather north and cooler weather south. SOURCE: NOAA.
El Niños normally make the northern states and Canada warmer and the southern states and Mexico wetter. Confusing, isn’t it!
Unfortunately, for my Ohio readers, parts of the Midwest have less snow, which means things stay dry.
Of course, El Niño isn’t the only pattern that shapes winter. If an Arctic Oscillation is in a negative mood, it will be cold. The Arctic Oscillation is the king of winter, and a “little boy” cannot fight a king.
So, if you love shoveling snow off your sidewalks, this winter may disappoint you. If you like cool but not frigid weather, El Niño may be your best friend.
Evelyn Browning Garriss, historical climatologist, is a longtime writer for The Old Farmer's Almanac. She is also editor of The Browning World Climate Bulletin and has advised farmers, businesses, and investors worldwide on upcoming climate events and their economic and social impact for the past 21 years.