2018 Weather Outlook

Andrew Pritchard

A wild winter has plenty of weather storylines on the board across the US as we head into spring 2018.

Before taking a look into the future, let’s talk about where we stand now and how we got here.

Winter 2017-2018 was a wild ride for the US. After repeated bouts of Arctic air in late December and January, February was quite warm for the Central and Eastern US, with a flip back to cooler weather in the Central US during the month of March. The dominant feature in late December and January was a weakening of the polar vortex, which allowed bitter cold Arctic air to invade much of the Midwest, with multiple rounds of accumulating snow reaching as far south as the Gulf Coast states. Since mid-February, the overall flow pattern of the jet stream has brought repeated rounds of rain to eastern Texas, eastern Oklahoma, Arkansas, southern Missouri, Tennessee, Kentucky, into central and southern Illinois/Indiana, and Ohio. This has led to flooding concerns in portions of the Ohio Valley and Mid-South that were previously worried about pre-season drought.


As April begins, many rivers in this area are in flood stage and soil moisture content is very high. Planting season is quickly spreading northward from the Mid-South into the Corn Belt, and this area needs to be watched closely for a pattern shift that would allow for a period of warmer, dry weather so that large scale planting operations may commence without additional delays.


As we look at the winter wheat crop in the southern plains, we continue to monitor what has been an exceptionally dry weather pattern across the panhandles of Texas, Oklahoma, and southern Kansas. Most of this region still has not received significant precipitation since October 2017. I toured portions of southwestern into south-central Kansas during the third week of March, and many of the wheat crops that I saw seemed to be fairing okay thus far. However, as we head into spring and the crops begin to come out of winter dormancy, it’s crucial that we shift to a weather pattern that brings additional rainfall to this region, or there will be major concerns over crop quality in this area.


Drought also extends across eastern Montana into the Dakotas. This region still has frozen soil and snow cover, which will begin to melt and increase soil moisture over the next 30 days. The mountains to the west have above average snow water content in Montana, Idaho, Wyoming, Washington, and parts of Colorado. Further south into California and Oregon however, snow water content is below 75% for most reporting stations.

As we look ahead to spring 2018, this very same active weather pattern is expected to continue into at least early May with cooler weather in the Central and Northern US. Frequent low pressure systems continue to bring precipitation to the already saturated Ohio Valley and Mid-South. To the West, dry conditions are forecast to continue across drought-stricken areas of Kansas, and the panhandles of Oklahoma and Texas. There are fears that the wheat crop in this area will begin to decline, but all hope is not lost. We have seen smaller precipitation events in this area in the past two weeks, and it only takes a small shift in the overall jet stream pattern to begin moving some of this wet weather to the west, which would further alleviate some of those concerns. We simply need to use caution when either worrying about increasing drought, or getting too excited about signals for wetter weather in this region because the mid-range weather models have been fairly poor at nailing down when we’ll see this current pattern break down. They’ve often hinted at a shift toward precipitation over the southern plains in the two-week time frame, only to have those hopes squashed with a doubling-down on this same flow pattern. Folks in the Corn Belt will also be keeping one eye on the drought situation to the west as we head into late-spring. If the drought survives into late May, it has historically transitioned north and east out of the plains and into the Corn Belt.

We’ll also have eyes on the northern plains this spring. Long-range guidance keeps this region cooler than average for April-May. Historically, cool and wet springs in the Dakotas lead to an increase in prevent plant acres. The last three years have seen below average prevent plant acreage due to favorable spring temperatures. Again, mid-range models have been relatively poor at predicting when we’ll see warmth return to this region, so pay attention to short-term forecasts as we head into these next few crucial weeks.

Looking ahead to summer, there is already growing worry about heat and drought across the Central US. We’ve had four consecutive years of high yields, which has many thinking “we are due” for a bad year. While there is some cause for concern, we need to be careful, as this kind of thinking does not apply to corn yields. Both the European and US models show support for drier conditions developing across the Central US and Midwest in July. While these models historically have not performed exceptionally well at 3-4 month forecasts, there has been consistency in their predictions, which is cause for concern. The positive at this time, is the very rainy pattern in this same region as we head into April. Any surplus moisture in this region in late May and June will be recycled through the season and at least slow the progression of drought from the central and southern plains. Additionally, corn and soybeans are tough plants that require substantial deviations from normal weather conditions before showing signs of stress.


So, what will we be watching for this summer? We’ll be watching for blocking patterns to evolve in June-August, the most common of which being a ridge in the jet stream over the Midwest/Corn Belt. This is the type of pattern that historically produces poor corn and soybean yields. This is another signal we’ll have to watch for in short-term increments. Typically, the development of a ridge in this area is not obvious months in advance but can be picked up in the 10 to 30-day time frame.

Best of luck for a successful 2018 growing season!