BETHLEHEM, Pa. — As the Lehigh Valley treks through its least-snowy winter on record (thus far), there are signs emerging that we may be in for a large-scale change of our weather pattern.
Experts are warning that La Niña may be over soon and El Niño — the warm-water current in the Pacific that can affect the jet stream and cause extreme weather around the world — could be in store for next fall and winter.
But what will it mean for our weather?
Based on history alone, fans of winter should be optimistic. But El Niño doesn't just affect one season, and scientists warn its possible return is a cause for concern.
Here’s what we know so far:
NOAA’s not buying in, yet
The National Oceanic and Atmospheric Administration said there’s an 82% chance that La Niña will have ended and neutral conditions will emerge by springtime (March–May).
But it cautions that forecasting the exact season (any three-month average) is challenging, since there are a range of potential outcomes shown in the forecast models.
NOAA said it needs to see more signs of an El Niño emergence, including the characteristic warmer-than-average tropical Pacific present for more than one or two months in a row.
For that reason, NOAA is not yet ready to issue an El Niño watch. That will come when uncertainty is erased and conditions are favorable for development of El Niño within the next six months.
Alarm bells are ringing
A quick Google search of the phrase "El Niño" will keep you up at night.
That's because scientists are warning it will exacerbate extreme weather around the globe.
Headlines are shouting of unprecedented heat waves, a higher risk of wildfires, devastating droughts, misery for farmers, and the risk of exceeding a key temperature threshold of global warming.
All of that could come in the Northern Hemisphere in 2024, which some are already suggesting will be the warmest year on record. (The hottest year in recorded history, 2016, was driven by El Niño, The Guardian points out).
What we do know is the La Niña to El Niño cycle causes fluctuating effects around the world, and while predictions are dire, the picture of what the future looks like currently is unclear, though experts say it could be much less murky by June.
Numbers tell the story for Lehigh Valley
Snow enthusiasts are surely clapping their hands at news of a possible El Niño. That’s because eight of the Lehigh Valley’s 10 snowiest seasons on record have had an El Niño component.
That includes our snowiest winter on record — 1993-94, when 75.2 inches fell.
Why is that?
During El Niño events, above-normal precipitation typically extends across much of the southern United States and can get pulled northward and affect our weather in the Mid-Atlantic.
Large thunderstorm complexes also tend to become more numerous during El Niño, experts say, and the moisture gets lifted into the atmosphere and transported across the country by powerful jet streams. That brings frequent occurrences of heavy precipitation to the region.
With that being said, it could be rain and not snow, as El Niño tends to bring milder temperatures to the Mid-Atlantic states.
Another factor could be a weak El Niño vs. a strong El Niño, which can cause quite the difference in average precipitation.
All of these factors make it far too early to know whether a potential El Niño pattern will emerge by next winter. But if it does, there’s a solid chance we’ll see more snow than the 2.9 inches that have been measured so far this winter in the Lehigh Valley.
