Two consecutive La Nina winters: here are the possible consequences

In short:

• Second La Nina winter;
• More widespread and precipitation;
• A phenomenon with different effects.

A different process

The La Nina phenomenon has a variable effect on the Quebec winters. The concentration of this cold water in the Pacific Ocean at the equatorial level has the effect of modifying the air flow at high altitudes. Result: The jet stream is jossed. “So winter takes on a different tangent than what happens in normal times,” explains meteorologist Regin Oimet at first glance.

Consequences of a moderate episode

When it comes to the moderate La Nina episode, the temperature is less than one degree below normal. In the past, the consequences have been multiple: we have observed more mildness and more rainfall in southern Quebec. Elsewhere, the rainfall was close to normal. “In the case of Montreal, during a moderate episode, we can expect to have more significant snow episodes,” Mr Oymet added.

Variable behaviors

La Nina is a long-term phenomenon with a logged impact. For example, in the winter of 2021, the province experienced a mild to moderate episode. However the weather that year did not respond normally. “Winter has the appropriate weather behavior for El Nino, which can happen,” the expert said.

Good to know: Unlike La Nina, El Nino is characterized by unusually high temperatures in the eastern part of the South Pacific Ocean. The appearance of this phenomenon is the end of the fishing season.

What happens if history repeats itself for two years in a row? Consider the 2018, 2012, 2009 and 2000 winter examples. Here are the second winters in common:

• They are generally cooler than their ancestors;
• Less snow fell with more precipitation;
• We usually notice more elaborate aspects.

In summary, these data indicate winters that are more mixed and active.

In collaboration with meteorologist Regin Oymet

See also: Ticks, still present in some winter conditions