Ag Weather Forum

La Nina Causes Southern Plains Drought Chances to Increase

Bryce Anderson
By  Bryce Anderson , Ag Meteorologist Emeritus
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Drought is forecast to develop across all the Southern Plains during the balance of 2021. (NOAA graphic)

The latest public and private forecasts for the next 30 and 90 days -- including the first look at the winter season 2021-22 -- put developing drought conditions for the entire Southern Plains region of the U.S.

This outlook offers a note of caution about prospects for next year's winter wheat harvest. Both DTN and the U.S. National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC) call for above-normal temperatures and below-normal precipitation across the U.S. Southern Plains during the November-through-January period.

In addition, the CPC Drought Outlook shows the entire Southern Plains region in the category of either "Drought Persists" or "Drought Development Likely". Such a forecast puts more than one-third of U.S. winter wheat production in potential drought concern. (Combined Kansas and Oklahoma winter wheat production accounts for 34% of the total U.S. winter wheat output.)

This drought outlook has a direct tie-in to the formation of a La Nina cool sea surface temperature event in the Pacific Ocean. The CPC notes that when La Nina is in effect, "the easterly trade winds strengthen and cold upwelling along the equator and the West coast of South America intensifies. Sea-surface temperatures along the equator can fall as much as 7 degrees (Fahrenheit) below normal."

When La Nina is in effect, the U.S. Southern Plains region has a strong outlook signal for below-average precipitation. In addition, the temperature outlook for the Southern Plains calls for above-average values during the coming winter season. This combination is potentially unfavorable for soil moisture in the Southern Plains wheat areas.

A forecast for drought development does not seem like much of a reach for the Southern Plains at this point in the first place. The Oct. 19 U.S. Drought Monitor shows portions of Kansas still drought-free; however, all of Oklahoma, The Texas Panhandle and northern Texas are either in some phase of dryness or drought. Below-average precipitation from here on would seem to simply move this region deeper into drought status.

Some winter wheat areas have heavier precipitation forecast. They include the Pacific Northwest, portions of the Northern Plains and the Midwest. Moisture would be especially welcome in the Northwest and in the Northern Plains. However, the combined acreage of these regions amounts to much less than the proportion of winter wheat output that comes from the Southern Plains and could be affected by drought.

Weather concerns may turn out to be no more than a floor for a market dealing with lower supplies than typical, however. A check with the DTN Analysis team shows caution about translating drought prospects into an automatic wheat market rally.

"EU wheat exports are reportedly up 64% versus a year ago (I have not confirmed yet but read from a good source). There is a shortage of good quality milling from there wheat due to the heavy rains, flooding at harvest ... Russia's internal wheat and flour prices are near record high, and Russian wheat export prices have risen for 15 straight weeks ... If I were to throw a third in there it would be the fear of rampant inflation that is leading to more investment in commodities," said DTN Senior Analyst Dana Mantini.

A question about total winter wheat acreage is still to answer as well. "There is likely nervousness right now as conditions have not been perfect there as wheat goes into dormancy, but total acres planted will definitely be a factor when we find out the actual (acreage total)," said DTN Cash Grains Analyst Mary Kennedy.

And there is also a reminder that wheat's famous resilience means production ability even when things look bad.

"May I remind everyone that wheat has nine lives," Kennedy said.

More details on the La Nina development are available here:

-- "La Nina Gets Stronger," at…

-- "Brazil Planting Progresses Very Quickly, Motivated by Double-Dip La Nina," (…)

Bryce Anderson can be reached at

Follow him on Twitter @BAndersonDTN


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