La Niña’s last hurrah? Pattern could disappear by this spring
Forecasters said this week that we have a better-than-even chance of La Niña fading by this spring
A weak La Niña is hanging on in the Pacific Ocean this month—even if it’s sticking around on borrowed time.
Forecasters recently announced that La Niña has a decent chance of fading by this spring. But that doesn’t mean the pattern’s influence will wear off just yet.
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La Niña may not be around much longer
La Niña forms when water temperatures in the eastern Pacific Ocean near the equator come in around 0.5°C colder than normal for several consecutive months.
The appearance of chilly waters in the eastern Pacific Ocean can have a ripple effect through the atmosphere that influences weather patterns sweeping over Canada.
After months of waiting for its arrival, forecasters with the U.S. Climate Prediction Center (CPC) announced in January that La Niña had finally arrived. However, it’s a weak event and it likely doesn’t have much staying power.
Experts with the CPC predicted last week that there’s a 66 per cent chance that La Niña will fade to neutral conditions between March and May. Neutral conditions exist when water temperatures in a critical region of the Pacific are close to normal.
La Niña flavoured our winter this year
A typical winter influenced by La Niña across Canada would see colder temperatures out west while the east contends with an active storm track and intrusions of mild air.
While this pattern can give us a general sense of the influences we may see on winter weather across North America, the fact is that no two events are ever exactly the same.
La Niña flavoured our winter this year, but the driving force behind this season’s conditions has been the polar vortex frequently settling into place around Hudson Bay and Baffin Island. Pulses of cold air have alternated between the west and the east so far this season.
This transition to neutral won’t hit like flipping a switch in the atmosphere. There will be a lag time during which we’ll likely still feel La Niña’s influence on overall patterns heading into the beginning of spring.
Winter certainly isn’t over yet. Canada often remains cold and wintry well into the spring months. It’s likely, though, that winter will continue to lack commitment to any one region in the weeks ahead.