US Drought Monitor
 
KANSAS CITY, MISSOURI, U.S. — It is interesting to note that while much of the commodity market attention recently has been on South America there is a large part of North America that has been quite dry this autumn and winter. Drought is affecting many areas from Mexico through the U.S. Plains to the heart of Canada’s Prairies. The area is normally responsible for much of the quality wheat and other small grains that are produced from North America, and if significant moisture does not fall soon the spring season could be marred by drought.

Precipitation has been well below average in most of the region from central and southern Kansas through Oklahoma, Texas and the southwestern United States to much of Mexico’s wheat region in recent months. A part of northeastern Mexico has had more normal precipitation, but the La Niña event that is underway is certainly curbing rainfall across all other parts of the described region and farther north, as well.

Precipitation in Canada’s Prairies and a part of the northern U.S. Plains also has been well below average this autumn and winter. The only exception has been in southern Alberta and across Montana, where precipitation has been greater than usual in recent weeks. Much of the moisture has occurred as snow remains stacked up on the ground. Some of the moisture from the snow will reach into the topsoil this spring as it melts, but frost in the ground will limit the soil’s ability to take in much of the moisture until the ground completely thaws. That is not likely before the snow melts.

Drought in Montana and southern Alberta lingering from last summer and autumn is still present, but the situation in these areas is not as serious as that in the heart of Saskatchewan and southward into portions of the western Dakotas. Portions of both Saskatchewan and South Dakota were snow free during the bitter cold outbreaks of late December and January. Temperatures at that time plummeted well below zero Fahrenheit and well below the potential damage threshold for unprotected winter wheat. Damage to crops likely occurred, but in the case of Saskatchewan drought last autumn may already have reduced the amount of wheat planting that took place. Nevertheless, production is bound to be lower due to winterkill and drought.

The lack of snow cover correlates well with the lack of precipitation in general, and even though some locations in the Canadian Prairies and northern Plains have had near normal precipitation, “normal” is not enough to change drought status deep into the soil. Subsoil moisture is critically low and will stay that way into spring, despite any significant snowfall that might occur in the next few weeks. Frost runs deep into the ground in the areas that have been snow free this winter, and it will not come out of the soil until late in the spring unless temperatures turn warmer than usual early in the spring, which seems unlikely.

In the meantime, worry over winterkill in the central U.S. Plains and in a small part of the lower Midwest is also present. Temperatures earlier in January slipped to -9 degrees Fahrenheit in southern Kansas and into the negative and positive single digits in northwestern Oklahoma, and the northern Texas Panhandle when snow cover was minimal. Dryland crops in the central Plains may have had a better chance of surviving the bitter cold without snow on the ground than irrigated crops. Irrigated wheat was much more susceptible to damage because of the more abundant moisture that was in the plants’ cells ready to burst when the crown of the plant froze hard and the odds are high that damage did occur.

Canada drought monitor
 
Assessing the losses in Canada and the U.S. central Plains will not be possible before winter crops green up in the spring. Some of the crop will green up, but may not be capable of filling heads with grain because of the cold damage and assessing the loss in that situation will not be possible until the harvest. To complicate matters a little more, some of the damaged wheat that does green up in the spring will have potential to set new tillers that might be capable of filling heads normally. However, for those crops that do tiller in the spring they will require significant amounts of moisture to restore favorable soil conditions to support new crop development. That brings us back to the original concern over dryness.

Rainfall over the 90-day period ended Jan. 22 was less than half of normal from north-central and west-central Kansas southward into the Texas Panhandle. Parts of Mexico’s wheat region also reported less than half of normal rainfall. Many areas in southern hard red winter wheat areas in the U.S. Plains received less than 15% of normal precipitation with a few areas completely dry. Farther north in the drier areas of South Dakota precipitation in the previous 90 days was 50% to 75% of normal while that in Canada’s central Prairies was less than 40% of normal outside of southern Alberta.

Not all areas have been dry. A recent blizzard from northeastern Colorado through Nebraska and far northwestern Kansas did produce greater-than-usual precipitation, but at this time of year normal precipitation is not very much. That region, like Montana and southern Alberta, however, has seen greater-than-usual precipitation that might be of some use to crops in the spring, but only in areas where frost is not in the ground.

The outlook for each of these drought-stricken areas does not offer much potential for change in the next few weeks. February is expected to start out quite dry with a new bout of bitter cold in the northern Plains and Canada. Recent forecast models have brought a little hope for a boost in precipitation in late February. At that time the cold air may pool into the western parts of the United States, and that should change the upper air wind flow to one that extends from southwest to northeast across the United States. A southwesterly wind flow aloft can bring needed moisture into the central Plains, but this year’s pattern will occur while weak La Niña conditions are prevailing. That may curb some of the precipitation potential, especially in Texas, Oklahoma and northern Mexico.

World Weather, Inc.’s official forecast does support the potential for greater precipitation in March and April from the southern Rocky Mountain region through the central Plains to the upper Midwest and western Great Lakes region. The pattern should bring some relief to dryness in the central Plains, but it is still questionable whether significant precipitation will reach into Texas, Oklahoma or Mexico winter crop areas.

In the meantime, Canada’s Prairies will be too far to the north for significant precipitation increases to occur through early spring. There is potential for improvement during the second half of spring, but some areas in western Saskatchewan and east-central Alberta may find it difficult for significant precipitation to reach into those areas until the start of planting. With low subsoil moisture the odds are high that crops will struggle with limited moisture into the early summer when rain finally does evolve.