El Niño Could Influence Winter Snowfall Across US, New Maps Show
As the United States braces for a winter season heavily influenced by the first significant El Niño in years, scientists at the National Oceanic and Atmospheric Administration (NOAA) have released maps that provide insights into where snow could pile up.
El Niño, a natural ocean and weather pattern in the tropical Pacific, is forecasted to reach its most significant level since the strong El Niño event in 2015-2016, which resulted in the warmest winter on record across the contiguous US, according to NOAA.
While no two El Niño winters are the same, the pattern typically brings wetter and cooler weather to the southern US while the northern regions become drier and warmer. This winter, a similar trend is expected.
However, it is important to note that wetter weather does not always translate to more snow. The amount of snow can vary greatly from one location to another.
To provide some guidance, NOAA scientists have created maps that show where snow is more or less likely during El Niño winters compared to the average. These maps are historical guidebooks and not forecasts, as actual snowfall predictions take into account various atmospheric and climatological factors, not just El Niño, said Michelle L’Heureux, one of the scientists behind the maps.
The maps depict snowfall differences from the average across all El Niño winters, highlighting the drier trend in the northern US with tan and brown shading, and the wetter trend in the southern US with blue shading.
The jet stream’s shift south during El Niño winters is particularly noticeable in the highest terrains of the West, resulting in increased snowfall. Mountains in the Southwest and California tend to thrive with snow, while the Northwest misses out due to fewer storms.
For the mid-Atlantic region, snow chances are typically influenced by storms that follow the Appalachians or push out to sea and become nor’easters. During El Niño, these nor’easters can deliver above-average snowfall to places like Washington, DC and Baltimore, potentially making up for the lack of snow the previous winter.
However, the Northeast, as well as the Northwest and Midwest, may need to rely on rare big storms to see significant snowfall during a strong El Niño winter. Stronger El Niños have historically caused less snow than average in these regions.
While the maps provide useful insights, they do not guarantee specific snowfall amounts. El Niño shifts the odds in favor of certain climate outcomes, but it does not ensure them, emphasized L’Heureux.
In conclusion, the new maps released by NOAA provide historical information on how snowfall during El Niño winters may differ from the average. The maps highlight the potential for wetter and snowier conditions in the southern US, while the northern regions may see drier and warmer weather. However, it is important to remember that these maps are not forecasts, and actual snowfall predictions consider various factors beyond El Niño.