As spring approaches, the ongoing La Niña phenomenon is starting to show signs of weakening. We may see a neutral phase throughout the spring that will change ongoing weather patterns across the U.S.
Let’s break down the seasonal outlook, how it changes from month to month, and why this happens.
Meteorological spring (March, April, May)
The prospect of spring brings some good news for those in the Northeast. Temperatures are expected to be slightly above average, but will start to drop the further you get into New England.
While the upper Midwest is also expected to experience below-average temperatures this spring, the rest of the country will continue to experience above-average temperatures, according to an outlook released Thursday by The Weather Company and Atmospheric G2.
Here’s what each month looks like.
March
In March, cold weather is expected to remain in the northern parts of the country. March temperatures should be below average in the upper Midwest, Great Lakes, mid-Atlantic, Northeast, and northernmost reaches of the Northern Plains.
By contrast, much of the southern, central and western United States is expected to experience above-average conditions.
The Northeast may still be craving more sustained warmth and will have to wait until March, too.
April
In April, winter conditions in this country will start to really change.
While temperatures remain below average across the upper Midwest and even parts of the Northern Rockies and Pacific Northwest, the same situation is not expected across the Northeast.
Temperatures are expected to be above average across the region, which is a very welcome change from the persistently cold temperatures that persist in parts of the winter.
Temperatures will continue to be above average across the southern half of the United States, with the Southern Rockies, Southern Plains, and Southeast most likely to experience warm weather.
possible
Warming trends continued throughout much of the Lower 48 in May. The greatest warming should be in the West, including much of the Rockies. While still above average, temperatures across the East are likely to be only slightly above average.
The only areas with cooler than average temperatures were New England (plus Michigan’s Upper Peninsula).
Precipitation Outlook
While temperatures are the topic of the moment as millions of people wait for the season to turn, we can briefly discuss precipitation and what’s likely to happen over the next three months.
This is more of the same. The east is wetter and the west is drier. That’s a good thing for the East because quite a bit of the region is actually dealing with drought. So hopefully this long-term prediction will be confirmed.
While Western countries have seen a brief shift from overall dry to mild seasons in recent weeks, they are hoping for more of a return to conditions seen during much of the winter.
What caused this shift and how certain are we about this prediction?
As spring approaches, the ongoing La Niña phenomenon shows signs of weakening.
For those who need a quick refresher, La Niña occurs when temperatures are below average in the central and east-central equatorial Pacific Ocean. El Niño is the opposite, with warmer ocean temperatures in these areas. These affect weather throughout the United States and the entire planet.
As La Niña weakens, that means new patterns are emerging and things will change. This pattern is the neutral phase of the El Niño-Southern Oscillation, which simply means that Pacific waters are not significantly above or below average.
So what does the neutrality condition mean for the United States?
Well, they do introduce more uncertainty into these forecasts, so be sure to take these long-term forecasts with a grain of salt.
Why does uncertainty exist? Summer is ending in the Southern Hemisphere and winter is ending in the Northern Hemisphere due to more neutral temperatures in the Pacific, with smaller temperature differences between the hemispheres.
Because the differences between the hemispheres are smaller, winds are also weaker at the equator, and wind is the main driver of El Niño and La Niña.
(More: La Niña fading: What warming waters mean for this spring, hurricane season)
But the trend for a neutral spring climate is for above-average temperatures in the south and southeast and cooler temperatures from the Central Plains to the northeast, with monthly forecasts particularly accurate in March and April.
We also have to talk about the jet stream, which is the main driver of our weather. It starts to weaken this time of year, which means our weather patterns aren’t as predictable in the long term.
What we know for sure is this: the transition to neutral status in the El Niño-Southern Oscillation (ENSO) is coming and will lead to some changes across the country. But many factors make the forecast more uncertain.