The first month of meteorological spring is set to be a continuation of lingering winter cold across the northern tier while most everyone else will be warmer than average, according to the latest outlook from The Weather Company, an IBM Business, and Atmospheric G2.

March will likely be warmer than average from the mid-Atlantic states across the Southeast, Ohio Valley, southern Plains and Southwest. The highest confidence of a warm March is in the Southeast.

Much of the North and Northwest may have a cooler-than-usual March. The best chance of a chilly March is from Washington state to northwest Minnesota.

This outlook does not mean that it will be warmer than average throughout the month in the South or cooler than average in the North, especially in spring, when weather can be particularly changeable. Rather, the South should have more frequent warmer than average periods, and the Northwest will have more frequent cooler periods.

Driving Factors

There are several ingredients behind this March outlook.

The first is La Niña, the periodic cooling of the equatorial Pacific Ocean waters, which can influence weather patterns across the globe, including in the U.S.

The current La Niña is gradually diminishing after peaking in December and early January, but its effects on the weather can linger.

Moving into the spring months, La Niña (or its opposite, El Niño) tends to have less impact on U.S. weather, but without any rapid changes in this climate signal, more of the same from previous months can be expected.

In La Niña, the jet stream remains far to the north with any cooler air locked in over the northern tier, hence the cooler forecast above.

Another factor this winter has been a strong polar vortex.

When this whirling cone of low pressure high over the poles is strong, cold air is less likely to plunge deep into North America or Europe and persist.

So-called "sudden stratospheric warmings" can weaken, stretch and displace this polar vortex, leading to long-lived cold outbreaks weeks later.

No such weakening of the polar vortex is in sight as we move into spring.

According to Todd Crawford, the director of meteorology at Atmospheric G2, a March that follows a winter with a strong polar vortex tends to be warm in most of the country except the Northeast. The Plains and South are typically warmest.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.