The challenge of putting together a spring weather forecast can be compared to the prospect of shooting skeet after a steady diet of trap shooting. With trap shooting, you can depend on a consistent flight pattern. Skeet comes at you in any number of ways. Good luck and good shooting!
Spring weather patterns for the U.S. offer similar vagaries. What appears to be a well-entrenched feature can change quickly—not necessarily on a dime, but in short enough order that favorable-looking areas can become problem centers—and trouble spots turn into, well, garden spots.
But while acknowledging these potential hiccups, there are enough big-issue features going on that forge their way into my thoughts for 2008. Such topics as La Niña, the Southeast's drought and soil moisture in the Midwest come quickly to mind.
These features—and their evolution—will go a long way to determining the whys and wherefores of the U.S. Crop Belt's fortunes this year.
The usual way of handling forecasts is to go through all the steps and then give the result at the end. But, I'm going to give you my conclusion—and then go through the steps.
And so, here's my spring 2008 perspective:
- Midwest and Delta: favorable crop weather
- Southeast: still dry
- Plains: improving crop conditions
Now, to the major factors in my weather outlook.
LA NIÑA TO DECLINE. Pacific Ocean cooling, known as La Niña, developed in September last year, and that timing bodes as a promising feature for the nation's 2008 row-crop season.
Here's the reasoning: The average span of La Niña is around eight to nine months. I look for La Niña to start weakening during late spring.
This offers a promising row-crop scenario for the Midwest and Delta—dry weather for spring fieldwork and planting, followed by a more energetic jet stream crossing the central U.S. And, with that stronger jet, there's a better chance at rainfall during June and July.
There is some concern 2008 could bring a repeat of the drought of 1988. Much of this worry is because 1988 was also a La Niña year in the Midwest. (See "No Repeat.")
However, there are some important differences between 2008 and 1988 worth noting. First, the La Niña of 1988 began in April, and intensified during the summer months.
Also, not only did the 1988 growing season coincide with La Niña, but the La Niña development came following a dry fall and winter of 1987/1988. The Corn Belt was already teetering on a troublesome situation as the 1988 spring season began; La Niña only made things worse.
Conditions are much different heading into the 2008 growing season. (CLICK HERE to see a chart demonstrating the moisture levels across the major crop-growing regions of the U.S.). The timing of La Niña's development has already been noted. Second, the U.S. Corn Belt is in a much healthier situation for soil moisture than 20 years ago.
Only a small portion of the Midwest—in western Illinois and southeastern Missouri—is on the dry side going into spring fieldwork. There is much more soil moisture for crops to work with—another reason to be optimistic.
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SOUTHEAST RIDGE LOOKS DOMINANT. The Atlantic Ridge is not a geographic feature. The name refers to a large, looming area of high pressure in the upper atmosphere, which has made camp over the South since spring 2007. In weather terms, this upper-level high is called a ridge, but we may as well call it a wall for the negative impact it's had on moisture over the Southeast.
These high-pressure systems block any storm cells that try to invade the territory inhabited by the high. We experienced the result of this feature in a major way last year when the Southeast endured its driest year in more than half a century.
I don't look for this large-scale feature to relax much—if at all—in the upcoming crop year. After all, it's common during summertime for a Southeastern high to strengthen; that's what the likelihood is again this year. That's why, in this view, the Southeast has another difficult growing season ahead.
On the other hand, air circulation around the Southeastern high (clockwise) promises to bring a consistent flow of moisture from the Gulf of Mexico northward into the Midwest. Thus, in a classic case of haves and have-nots, the Midwest stands to benefit from the mechanism that keeps the Southeast dry.
What could change this outlook for the Southeast? One fact needs to be underscored: The high will not go away.
The best circumstance for the Southeast would be for atmospheric conditions farther east in the Atlantic to encourage the high to move farther eastward—into more of an open-ocean location.
That would allow for more of a storm track across the southeastern U.S., and would bring states like Mississippi, Alabama, Tennessee, Georgia and Florida into a more promising rainfall pattern.
PLAINS CONDITIONS TO IMPROVE. Wheat planting in the Plains hard red winter wheat areas was a difficult task in 2007 because of dry conditions. That dryness has taken an early toll on crop status; emergence of the 2007/2008 wheat crop was subpar.
Spring weather prospects in the Plains are less promising than in the Midwest. However, I see enough potential in the tailing-off of La Niña, along with the strength of the Southeastern U.S. high, to be optimistic about improving conditions this spring.
Timing of storm systems and medium-term weather happenings will, of course, be the final keys to how crops perform. But, in general, I see plenty of reasons to look forward to the 2008 growing season weather-wise. Good planting to you!
No repeat
Twenty years ago, a La Niña-influenced drought devastated crop yields, shaving the U.S. corn crop by 30% compared with the 1987 harvest. Here's why a drought of that magnitude today isn't likely to have the same impact:
MORE SELECTIVE BREEDING FOR DROUGHT. During my television days following the 1988 harvest, I interviewed several seed corn company executives on their plans to respond to the calamity. The gist of their comments was unanimously: "We will do everything in our power to make sure this [sharp drought loss] doesn't happen again."
They have. Crop varieties and hybrids which performed well in spite of the difficult conditions were identified and incorporated into breeding programs.
HYBRID STABILITY DEVELOPED. A major factor in seed improvement has been "hybrid stability." In effect, the corn plant is better able to respond to adverse conditions than hybrids of 20 years ago.
ROOTWORM PROTECTION TRAITS. Give a bow to biotechnology. Twenty years ago, crops were treated for rootworm infestations. By that time, at least some damage had already occurred.
Today, rootworm resistance is in the seed before it's planted. This gives the corn plant a better chance at full root system development and effectively lets it go after all available water and nutrients.
CONSERVATION TILLAGE. The widespread use of conservation tillage may be the best defense against major drought. By making fewer trips—and opening up the ground as little as possible—farmers keep whatever moisture has accumulated in the soil profile.
Putting some numbers to this scenario, our DTN ballpark estimate is that an exact repeat of 1988 in 2008 would result in a yield loss of 10 to 15%—around half the loss we saw 20 years ago. We'll go with the midpoint of that range—about 12.5%.
Applying that figure to the Iowa and Illinois corn yield brings this prospect: The Iowa/Illinois yield in 2007 was 175 bushels per acre. A yield loss of 12.5% produces about a 20- to 25-bushel-per-acre reduction. The result would be a corn crop in the range of 150 to 155 bushels per acre for the Iowa/Illinois average.
But as noted in our forecast, this scenario's likelihood of a lock-step repeat is unlikely.
CLICK HERE to see a chart demonstrating the moisture levels across the major crop-growing regions of the U.S.