Ag Resource Crop Tour So Far – Critical Weather Ahead!

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Highlight: AG Resource Crop Tour finds mixed results in Illinois to Iowa.

Fig. 1: NOAA daily soil moisture anomaly analysis.

Discussion: The AG Resource Midwest U.S. Crop Tour marches on westward after finding better conditions to the east and worsening conditions to the west (although not as bad as expected). The findings are well-supported by soil moisture analysis (Fig. 1). Summer of 2022 has featured weather extremes for crop areas. Expected drought has generated in the Central Great Plains but “renegade” thunderstorms have made dry-to-drought issues patchy at best for the central U.S. Corn Belt while well to the east has been wet. The larger problem is heat which has accelerated dryness in areas where drought developed.

Fig. 2: The August 2022 U.S. soil moisture change (so far).

Fig. 3: Deep layer (10-200 CM) soil moisture deficits for August 2022.

The August soil moisture change also supports Crop Tour findings as streaks of rain have benefited parts of Iowa and Illinois while central and southwest Iowa have not received much rain (Fig. 2). Soil conditions have worsened in Kansas, especially eastern sections and dryness in the spring wheat areas of the northern Great Plains and Canadian Prairies are a new concern. Entering late summer, deep layer soil moisture deficits which can foreshadow future drought, acceleration of current drought or flash drought if the climate stays dry have become vividly present from southeast Oklahoma to southeast Minnesota (Fig. 3). On its own, this is a scary look for late summer soil conditions.

Weather forecasts for August into September are critical. The next 3 days feature another “renegade” wet weather event benefiting the northwest to central Corn Belt (Fig. 4). We say “renegade” due to the dynamic northwest flow aloft entraining moisture from this year’s prolific Southwest Monsoon which has caused streaks of rain that can be (and often are) excessive. ECM indicates wide aerial coverage of 0.50 to 2.00 in. of rain today through Saturday and more could occur given the precedent set by this year’s rainfall events in this area. Next week forecast models are mixed with ECM offering wet weather for North Dakota and parts of Minnesota (and dry elsewhere) while GFS is wetter for Iowa/Illinois and South Dakota to Minnesota. Figuring out what level of involvement the super wet Western U.S. Monsoon has on the Great Plains Crop Areas is difficult making forecast models unreliable beyond the short-term. To address the 6-10-day forecast we use the mega-cluster ensemble which is biased toward the ECM solution (Fig. 5). Note the limited forecast confidence (35%). The model indicates dryness across the Ohio Valley, a drier trend. The “caveat” forecast is drier. So…dryness is likely for the central and eastern Corn Belt for much of next week.

Fig. 4-5: ECM 3-day rainfall forecast for the AG Belt and mega-cluster ensemble “most likely” rainfall anomaly forecast for the 6-10-day period.

In the 11-15-day period, most forecast models agree on some sort of weakness in the upper air across the southern Great Plains. Consequently, the forecast remains wet in Texas and the Mid-south U.S. and that wet weather extends to the Ohio Valley (Fig. 6). Dryness is there but shifts westward. The 6-10/11-15-day forecasts illustrate the Climate Impact Company opinion of weather/climate on the U.S. Corn Belt for late summer. Occasionally threatening but just when dry concerns accelerate, rains appear. Once again, for the moment, extended-range forecasts turn dry again for the U.S. Corn Belt and North-central U.S. (Fig. 7).

Fig. 6-7: Mega-cluster ensemble “most likely” 11-15-day rainfall anomaly forecast and the NCEP CFS V2 16-20-day percent of normal rainfall forecast.

Summary: Late summer forecasts for the U.S. Corn Belt are offering enough rain to prevent widening crop difficulties. However, as always, it’s a close call and we’re in “counting raindrops” mode heading into September. New ECM “weeklies” are issued later today providing re-assessment of the 2-4-week outlook. Also, NOAA issues new long-lead climate forecasts including a 90-day drought outlook. Once data is received, Climate Impact Company will issue analysis.