As spring approaches, the ongoing La Niña is beginning to show signs of weakening. We will likely see a neutral phase in the spring, and this will change the weather patterns that have been underway in the US.
Let’s look at the seasonal outlook, the change each month and why this happens.
Meteorological spring (March, April and May)
The spring outlook brings some good news for those living in the Northeast. Slightly above average temperatures are expected, although the trend starts to cool the further you go into New England.
While some below-average temperatures are expected this spring for the Upper Midwest as well, the rest of the country will continue to see above-average temperatures, according to forecasts released Thursday by The Weather Company and Atmospheric G2.
Here’s how things look from month to month.
March
For March, cold temperatures are expected to remain in the northern part of the country. The Upper Midwest, Great Lakes, Mid-Atlantic, Northeast, and northernmost portions of the Northern Plains should see below-average temperatures for March.
Compare that to the southern, central US and most of the west, which are expected to be above average.
The Northeast, probably still yearning for more consistent warmth, will have to wait until March as well.
April
April will really start to see a change in what happened in the country over the winter.
While below-average temperatures remain in the Upper Midwest region and even include parts of the Northern Rockies and Pacific Northwest, the same is not expected for the Northeast.
Above average temperatures are expected to blanket the entire region, which is a very welcome change from the constant cold that has remained for parts of the winter.
The southern half of the country will continue to see above-average temperatures, and the best chance for some warm weather will span the Southern Rockies, Southern Plains, and Southeast.
May
The warming trend continues across much of the Lower 48. Areas that should see the most warming are the West, including much of the Rocky Mountains. Although still above average, the east could only see slightly above average temperatures.
The only area leaning toward below-average temperatures is New England (plus Michigan’s Upper Peninsula).
Rainfall outlook
While temperatures are the topic at hand as millions await the changing seasons, we can briefly talk about rainfall and what the next three months could hold.
It’s more of the same. Wetter in the east and drier in the west. This is good for the East, as a surprising portion of the region is actually experiencing drought. So, hopefully, this long-term prediction checks out.
Even though the West has experienced a brief pivot to the dry and mild season in recent weeks, they are looking to return to more of what they saw most of the winter.
What is causing the change and how confident are we about this prediction?
As we move into spring, the ongoing La Niña is showing signs of weakening.
For those who need a quick refresher, La Niña occurs when the Pacific Ocean sees below-average temperatures in the central and east-central parts of the ocean’s equatorial region. El Niño is the opposite, with warmer ocean temperatures in those regions. They influence our weather across the US and the entire planet.
With a weakening La Nina expected, this means a new pattern is emerging and conditions will change. This pattern is the neutral phase of the El Niño-Southern Oscillation, which means, in short, that Pacific waters are not significantly above or below average.
So what does neutral terms mean for the US?
Well, they throw a little more uncertainty into these forecasts, so be sure to take these long-term forecasts with a grain of salt.
Why is there uncertainty? With more neutral temperatures in the Pacific, you have less temperature difference between the hemispheres because summer ends in the southern hemisphere and winter ends in the northern hemisphere.
You also have weaker winds at the Equator due to the less extreme differences between the hemispheres, and the winds are the main determinant of El Niño and La Niña.
(More: La Niña Fading: What warm waters mean for this spring’s hurricane season)
But the trend for neutral conditions during spring is for above-average temperatures in the South and Southeast and cooler temperatures from the Central Plains to the Northeast, which the monthly forecasts for March and April look particularly good.
We must also talk about the jet stream, which is the main engine of our time. It starts to thin out at this time of year, which means our weather patterns aren’t as easy to predict in the long term.
What we’re sure about: A shift toward neutral El Niño-Southern Oscillation (ENSO) conditions is approaching and will lead to some changes across the country. But a lot of factors contribute to a more uncertain prognosis.