CHICAGO — Planning for a fair amount of weather uncertainty will continue to be a challenge for farmers.
“This past year we were swamped,” said Bryce Anderson, senior agricultural meteorologist at DTN. “We have washed out fields in north-central Illinois where I would not expect to see in mid-July.”
Anderson talked about consistent warming trends during the fifth annual AgTech Nexus USA conference, presented by Global AgInvesting and co-hosted by the Illinois Soybean Association. The event included international investors, agribusiness executives, agtech entrepreneurs and farmers.
“The Earth’s temperature continues to advance and during June temperatures were 2.4 degrees above the 20th century average,” he said. “It was the highest June temperature on record since records began in the 1880s.”
During the January to June timeframe, Anderson said, the temperature this year tied with 2017 for the second highest temperature on record.
“In conjunction with that, the greenhouse gas accumulation continues to advance as well,” he said.
The warmest areas during June included Europe, much of south Asia, South America, northern Russia and Alaska, Anderson said.
“There was not much of a cooler trend on any spot on the globe,” he said. “There was a little bit of a relatively cooler trend in the central part of the U.S. and along the Central Asia region, but there was no spot that had a record cool month of June.”
One of the biggest areas of the world that has warmed dramatically is the Arctic, Anderson said.
“The warming to the north is having a ripple effect on our weather patterns in the mid latitudes,” he said.
“There’s been a fair amount of research looking at what the warming in the Arctic does to the jet stream track across the middle latitudes,” he said.
“When you have warming going on and a lowering of the differential of temperatures between the north and middle latitudes, the jet stream track tends to slow down and once the weather patterns get going they tend to lock in place over an extended period of time.”
And when precipitation develops it is more likely to result in heavy downpours.
“These are occasions where rainfall in a 24-hour period exceeds 1.5 inches, which is the threshold at where filtration into the soil profile ends and runoff begins,” Anderson said.
The rainy pattern during spring 2019 occurred when warmth in the far northern latitudes led to a big area of blocking high pressure which sat there for months — late February to early June, he said.
“There was colder air over the north central and western U.S. and at the same time there was a ridge of high pressure at the tropics with warmth in the Gulf of Mexico and western Atlantic that sat over Alabama and Georgia,” he said.
“That led to a virtual mainline highway for moisture to move from the Gulf of Mexico through the central part of the country to develop the environment for heavy, repeated rains.”
This pattern, Anderson said, was almost exactly like the pattern during the fall of 2018 that led to the delayed harvest and a wet season.
“We had record spring moisture after record fall moisture, and now we have heavy soil moisture situations,” he said.
Farmers now have a lot of questions about crop development.
“We have many holes in the fields and crops far behind average,” Anderson said.
“Going into mid-July, we had deficits of 90 to 150 growing degree days over much of the western and northern Midwest,” he said.
“We have crops that are going to be pushing the finishing line, and as we get further into the month of August, there’s going to be much attention on temperatures,” he said.
Changing weather also is impacting the growth of weeds.
“U.S. Department of Agriculture researchers have done a lot of work on the climate change scenario and how it affects crop and weed growth,” Anderson said. “The findings have been that weeds are outgrowing crops and weed response to climate change is outpacing crops and control.”
In addition, he said, pests are moving north and expanding their range. Examples include the brown marmorated stink bug, the Japanese beetle and tar spot.
“Tar spot use to be confined to the south, and now it’s expanded into the Midwest,” Anderson said.
He reported the El Niño conditions are starting to fade as the water temperature in the Pacific is starting to show some cooling.
“The Pacific looks like it is going to be in a neutral phase as we go through the balance of the year,” he said. “And the impact on the Midwest weather is for less favorable conditions for an early frost.”
For more information about Global AgInvesting, go to www.globalaginvesting.com.