La Nina to bring weather reversal
Corn Belt should receive good moisture and temperatures near normal in 2020 growing season.
Weather patterns are going to start being quite different from the last five or six years as El Nino conditions are expected to shift to La Nina conditions this year, according to Dr. Art Douglas, professor emeritus at Creighton University.
While the shift may mean hotter, drier conditions for some areas already experiencing drought, the weather in 2020 will play a supporting role for agriculture. Conditions will be slightly warmer and drier than last year, which Douglas said will be favorable for planting and growing conditions during the spring and summer.
“If you look off the coast of California and South America, we’ve started to develop some very cold water across the coast, and that is a precursor then to rapid development of La Nina,” he explained.
In the central Pacific, near Hawaii, it is really warm, which is also a pattern typical of La Nina.
Currently, drought is still present in the in the Northwest from the continuous El Nino event. There’s also dryness in the central Rockies and Texas, but it’s Texas that will be the major concern going forward, Douglas noted.
The northern Plains have seen a lot of moisture, but this has started to turn dry as La Nina conditions have begun to emerge.
“I think it’s going to stay that way,” Douglas added.
La Nina brings a lot of cold air south from Canada toward its border with the U.S., but at the same time, a strong Bermuda high is going to try to prop that cold to the North.
“The two working against each other says we’re going to have a lot of ups and downs, just like Texas has been having over the last couple of weeks -- really warm days when the Bermuda high pushes in, and then all of a sudden cold days when this flow from the north comes down out of Canada,” Douglas said.
Current forecasts for February suggest that it will be quite cold in the northern Plains and warm in the Southeast because of the Bermuda high. Douglas said the warmth is probably a good forecast, with temperatures expected to be 2-4°F above normal all the way through the Southeast. The cold in the North, however, will be only 2-3°F above normal due to no snow cover, he added.
Regarding the spring forecast, Douglas said below-normal temperatures are on tap for Montana into the eastern U.S., but they will not be as cold as what will occur in February. Further, a developing ridge will cause very warm, dry conditions from southern California into the southern Plains.
He said the winter wheat areas of the Plains are in a marginal situation and may not have a good crop this year.
The Bermuda high is still pumping a lot of moisture through the Mississippi Valley up into the Ohio Valley, but Douglas said the Dakotas will remain dry, which is, “again, very different [from] last year.”
Looking ahead to summer, hot and dry is expected for California. The far northern tier states will also be warm. In fact, Douglas said about the only moisture for the U.S. in the summer will be coming from the Atlantic, in toward the East Coast and then into the Ohio Valley.
Temperatures for the inner-Mountain West and all the way down into Texas will be very hot, he added.
It’s good news for the Corn Belt, though, as good moisture and near-normal temperatures should mean a decent growing season. Cooler temperatures won’t start to develop until August. Likewise, in terms of precipitation, Douglas said the summer should start on the wet side but will turn drier toward the end of summer.
In other words, La Nina means a reversal of conditions from recent years.