U.S. hard red wheat dryness not a rainfall problem
This year’s drought in the central Plains is actually not a byproduct of poor rainfall — the problem has been temperatures.

OVERLAND PARK, KAS. — Many wheat production areas in the Northern Hemisphere have experienced a mostly favorable winter season. Winterkill is down in Russia, Europe and Ukraine while that in the United States has been considered relatively normal. Crops are awakening around the Northern Hemisphere, and many have favorable soil conditions to support a good start to the growing season. The biggest exception is hard red winter wheat production areas in the United States, where parts of the high Plains region are in a drought.

Drought has been claimed by the U.S. National Oceanic and Atmospheric Administration’s (NOAA) Drought Monitor. Dryness in the U.S. central Plains has been reduced twice since the beginning of this year. The first time was in mid-January, and the second in mid-February. In both cases rainfall was most significant in Texas and Oklahoma with the event in January also affecting Kansas in a significant manner. Some of the high Plains region never received a general soaking of moisture, and the region is still dry.

This year’s drought in the central Plains is actually not a byproduct of poor rainfall — the problem has been temperatures. Rainfall in the most recent 90 days has been near to above average in the majority of wheat production areas, although some counties and parts of counties in central Kansas and a few from southeastern Colorado into west-central Kansas have reported moisture totals as great as 25% less than usual. That is not enough to induce drought.

Precipitation deficits in the region in the past 90 days as well as since Oct. 1, 2016, and for the past six months are not far off from normal. The only per cent of normal rainfall chart that shows a deficit is for the water year that began Oct. 1. If so much of the precipitation going back six months has not deviated far from normal, then why is there a drought in the west-central high Plains? The answer to that is temperatures. The past couple of years have been considerably warmer than usual at times. The month of February generated many record and near record high temperatures in the U.S. Great Plains and across most of the Midwest.

The persistence of warmer-than-usual weather kept evaporation rates higher than usual, and the losses of moisture through evaporation is the cause of drought. This pattern raises many new questions. Because the rainfall pattern has been mostly near normal then does that imply that spring weather will be more normal once the temperatures cool down? That is the big question. It should be reassuring to some farmers in the central Plains that they are not in a true drought pattern — at least not yet.

U.S. hard red wheat dryness not a rainfall problem

Concern has risen over dryness in the west-central high Plains. If the moisture deficits are not removed in the next few weeks, the dryness may help to induce a stronger summer ridge of high pressure over the middle of the United States. High pressure ridges aloft love to be centered over dry regions. When they are located over wet areas there is a tendency for the ridge to break down.

High pressure ridges centered over wet areas will warm the soil and draw moisture out of it through quick evaporation. The moisture then rises along with the warm air until it reaches a height in the atmosphere where the surrounding air is cool enough to condense the moisture as rain. Once rain evolves under the high pressure ridge the high pressure ridge breaks down. This phenomenon does not occur when high pressure ridges are centered over areas of dryness, and that is one of the many reasons why dryness in the central U.S. Plains is a concern beyond that for wheat production.

Moisture deficits are not just confined to the central Plains but extend to the east into the southwestern Corn Belt, the Delta and a part of the southeastern states. In a normal year, having moisture deficits in these areas in early to mid-March is not a concern because spring rainfall can and often does become significant during the spring and early summer from the central and southern Plains through the Midwest. However, with so much of the nation running notably warmer than usual in February, and the memory of 2012 drought still fresh on everyone’s mind, it will be difficult to shake off the nervousness until significant precipitation falls.

World Weather, Inc. believes there will be some support for improved precipitation later this month and in April for many of these drier biased areas. A complete restoration of soil moisture may not take place, and the situation will need to be closely monitored. However, there should be some timely rainfall for all areas that have a little moisture deficit, including U.S. hard red winter wheat areas. That should translate into improved crop development.

World Weather, Inc. believes spring rainfall will be a little lighter than usual in the northwestern corner of hard red winter wheat country. Temperatures in the balance of March and April likely will trend more seasonable, and there may be some periods of slightly cooler biased conditions in the heart of spring. If the forecast is correct some of the drier biased areas in hard red winter wheat country will get partial relief this spring, but northwestern areas may continue a little drier biased.

U.S. hard red wheat dryness not a rainfall problem

This year’s wheat crop may not be in the best of condition, but it does have a favorable root system. Timely rain — even if amounts are below average — would go a long way in supporting a good production year.

In the meantime, a close watch will be made on the Delta and southeastern parts of the nation for a little later this spring when there may be a little more dryness and warmth to deal with. The warm and drier bias may have more to do with spring and summer crops than to winter crops.

The only other small grain production regions in the world that may have some issues with adverse weather are Russia and North Africa. In the case of Russia, the problem may be with spring planting delays because of significant snow that must be melted before fields can dry out sufficiently to support spring planting. The ground is saturated beneath the snow in Russia, and that will add to the delay in gaining access to farmland.

In the case of North Africa, soil moisture is favorably rated today, but rain is not likely for a while, and the reproductive season is not far away. Timely rain will have to resume soon to assure a good production year, although there is potential for timely rain to evolve, according to the World Weather, Inc. Trend Model.

Another issue to keep in mind for the future is the possible developing El Niño. World Weather, Inc. still believes El Niño will not evolve anywhere near as quickly as NOAA’s forecast model suggests. That model was predicting an El Niño event by April 1. There is no way that will happen, but if it did Australia’s winter crops would be threatened with drought in their late winter and spring season, and India’s monsoon may fail. The NOAA forecast model is beginning to show signs of backing off the El Niño forecast, but it has not reached that point yet.