July Ag Weather Outlook

July Ag Weather Outlook June 14, 2018

U.S. Where We Stand The start of the growing season has been a study of extremes. An extremely cold April was followed by an extremely warm May. Rarely, if ever, has there been a month-on-month change transitioning from historic cold to historic warmth in the central/eastern U.S. Below are the temperature rankings for both months; the scale is 1-124 with 1 being the coldest and 124 being the warmest since 1895.

The record warm May was highly beneficial from an agricultural standpoint since it solved the problems via the extremely cold April. As a result, the summer crops (corn, soybeans, and spring wheat) are in very good shape with near record conditions for this time of year. The pattern during the next few weeks will maintain these conditions which gets us to the end of June. The question that we want to answer in this report, what are prospects for July? In stating the obvious, July is a critical period when weather has a significant impact on yield prospects. This is especially true for corn and spring wheat which will go thru their yield-sensitive stages (pollination and heading) and to a lesser extent soybeans, which will go thru their most sensitive stage (pod development) in August.

Call us: 312-600-7531

Email us: [email protected]

The Variables (1) May/July Spikes We will begin our analysis by asking and answering the question, does the period of significant early season heat across the Midwest at the end of May tell us anything at all about the possibility (or lack thereof) for a period of significant heat (or cold) in July? To answer this question, we compared 5-day average temperature data going back to 1980 across the Midwest region between May 1531 and between July 1-31. If temperatures were at least 8°F above or below normal for a 5-day window during the end of May, we counted this as a period of significant heat or cold. Likewise, if temperatures were at least 5°F above or below normal for a 5-day window during the entire month of July, we counted this as a period of significant heat or cold. The graph below shows this data. For reference, the solid bars are the “spikes” both hot and cold in late May while the hatched lines are the “spikes” for July.

The major takeaway is that a 5-day period of significantly below normal temperatures in July has almost never been preceded by 5-day periods of significant heat during the end of May; the only exception is 1991. In other words, since the Midwest experienced 6 consecutive and rolling 5-day windows of significant heat towards the end of this past May (the largest count of any year since 1980), historical data tells us that it is highly unlikely that this July will then feature a 5-day window of significantly below normal temperatures. What this analysis didn’t necessarily tell us was how likely or unlikely a period of significant heat would be in July, following a period of significant heat in May.

July Ag Weather Outlook

Call us: 312-600-7531


2

(2) Tropical Forcing Next, we will investigate how tropical forcing (enhanced/suppressed thunderstorm activity in the global tropics) impacts the timing of heat/cold during the month of July. The location of tropical convection or tropical thunderstorm activity is related to temperature outcomes across North America. Tropical thunderstorm activity in early July will be in a location that favors warmer-than-normal temperatures across the central and eastern U.S. In other words, enhanced thunderstorm activity in the Indian Ocean is connected to warmer-than-normal temps in the central and eastern U.S., while enhanced thunderstorm activity in the West Pacific Ocean during July favors colder-than-normal outcomes across the same regions. These outcomes are highlighted in the included figure, which is a tracking index for tropical thunderstorm activity. Bottom line, tropical thunderstorm activity is projected to start off July in the warm phases of the Indian Ocean.

(3) Southwest Dryness (EMLs) Below is a map which depicts the percent of normal precipitation over the past 90 days across the lower 48. So far this spring (mid-March to mid-June), the most concentrated dryness continues to be aligned across the southwest quadrant of the Nation. This is the breeding ground for hot air masses to form, build, and move out of. We continue to feel that these heat bursts or EMLs (elevated mixed layers) will be an important issue as pockets of hot air form over the central Rockies plateau and then move into the central U.S. causing a higher probability of heat spikes in the central U.S. The dryness in the Southwest and the higher potential for EMLs is why the highest probability of heat in July is in the Rockies and Plains versus the eastern U.S.


Call us: 312-600-7531


3

Forecast The maps below depict the probabilities of heat and dryness for July. The highest risk for heat is in the Plains and Rockies while the area with the lowest risk is the eastern U.S. As for precipitation, the highest risk for extreme dryness is in the northwest portion of the U.S. while the least likely area is the southwest quadrant of the Nation. As for precipitation, the sea surface temperature (SST) configuration in both the Pacific and Atlantic suggests a drier bias in the western U.S. and a wetter bias in the southeast. Hence in the central U.S. ag belts, the risk of dryness issues increases in the more western locations and decreases in the more eastern locations; i.e. the western Midwest is more at risk of dryness issues than the eastern Midwest.

Conclusions From an agricultural standpoint, our research indicates a greater chance versus climatology (or normal) of heat stress in the western Midwest and central/ northern Plains. The crops that would be most vulnerable to this are corn in the western Midwest corn belt and spring wheat in the northern/central Plains. The areas with the lowest amount of agricultural risk include the Southwest, eastern Midwest, and Delta.


Call us: 312-600-7531


4

Global Europe and the Black Sea Region Heat risks will be heightened versus climatology in July across much of Europe and the Black Sea. Furthermore, the highest probabilities of heat risk will be in Eastern Europe, including Ukraine, continuing the theme of warmth this spring. Our reasons for the increased heat risks: • Recent trends - Spring 2018 has featured ridging of high pressure oscillating across Europe and western Russia. This ridging developed unusually early this year and has been northern biased. As a result, temperatures in April, May, and so far in June have been biased distinctly warmer than normal across the vast majority of Europe and the Black Sea ag belts. • Model guidance - The latest Euro Weeklies and CFS climate models are projecting ridging of high pressure to continue to be a player in the pattern across the Europe and Black Sea Region throughout July. Ridging/ frequent heat looks a bit more prevalent in Eastern Europe vs Western Europe. • Global SST configuration - The current warmer than normal SSTs surrounding Europe, in the northwest Atlantic and northeast Pacific signal a warmer than normal July for Europe. In terms of the precipitation outlook, there is increased risk of dryness in July across Eastern Europe and the Black Sea Region. Confidence is medium with this forecast. Probabilities for below normal rainfall totals are highest in northern Germany, Poland, the Baltics, Ukraine, and southwest Russia as the projected ridge axis look more centered over Eastern Europe. The variables that signal these July drought risks include:


Call us: 312-600-7531


5

• Recent trends - Soil moisture is currently low across Scandinavia, the Baltics, and Ukraine/Russia due the prevalent ridging and below normal precipitation totals this spring. • Model guidance - The latest Euro Weeklies and CFS climate models are projecting ridging of high pressure to continue to be a player in the pattern across the Europe and Black Sea Region throughout July. Ridging looks a bit more prevalent in Eastern Europe vs Western Europe. Countries directly under and east of the ridge center would see the lightest rainfall totals. • Global SST configuration - The current warmer than normal SSTs in the Mediterranean Sea, North Sea, northwest Atlantic, and northeast Pacific signal a higher risk for a drier than normal July in Europe.

Crops that would be most vulnerable to increased heat/dryness risks include corn, sun seed, and small grains, especially in the eastern countries.

China, India, and Canada Elsewhere across the Northern Hemisphere, no issues are seen evolving across eastern China next month. Specifically, near normal rainfall is forecast for the corn, soybean, and cotton belts next month. Additionally, a slight warm bias is predicted for the northern corn/bean belt in Manchuria. In India, while the second half of June features sporadic monsoon rain activity, we don’t expect this to continue into July. In fact, we are forecasting near normal rainfall across the main summer crop belts in July. Finally, there are slightly elevated risks for heat and dryness across the Canadian Prairies next month. This is especially true in the acreage closest to the U.S. border.


Call us: 312-600-7531


6