PORTLAND (WGME) — Whether it was Charlie’s winter forecast or the rest of our Weather Authority team mentioning it, you’ve probably heard of La Niña before.
What exactly does it mean and how does it affect the U.S?
La Niña and El Niño are part of ENSO, which stands for El Niño/Southern Oscillation. They are both natural climate patterns that alter the sea-surface temperatures of the Pacific Ocean. El Niño and La Niña events typically alternate every 2 to 7 years. El Niño lasts about 9 to 12 months, with La Niña lasting upwards of 3 years.
They are opposite extremes of one another, as El Niño causes SST in the Pacific to become warmer than normal. In a La Niña year, the SST is cooler than normal. The warm water that was once present shifts eastward to Asia, causing the jet stream to shift further north than usual. Upwelling also occurs, attracting cold and nutrient-filled waters to the surface. Canada and the Pacific Northwest typically see heavy rains and flooding while the southern U.S. experiences a drought.
As of November 14, NOAA has issued a La Niña Watch, indicating a 57% chance of La Niña developing between October and December, possibly continuing through March.
We expect a weak La Niña this winter, so what does that mean for us locally?
Weak La Niña events typically indicate colder-than-normal temperatures and increased precipitation for the Northeast. These events are also associated with a greater likelihood of snow.
The strength of La Niña is important, as a strong one can limit snowfall.
Based on the new seasonal outlooks from NOAA, warmer-than-average temperatures are favored for New England.
New England has a fair chance of seeing near-normal, above-normal, or below-normal precipitation this winter.
You can stay updated on the latest ENSO status by clicking here.
Do you have any weather questions? Email our Weather Authority team at [email protected]. We’d love to hear from you!
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