The following content was provided by meteorologist Gail Martell of MartellCropProjections.com:
Midwest Drought Lingers On, Yields Shrinking
Midwest corn and soybeans are deteriorating with persistent drought; the most intense in the top two producing states of Iowa and Illinois. Rainfall has been sparse over the past 45 days in the western, northern and central Corn Belt. Despite cooler temperatures, reducing evaporation, moisture stress worsened in corn during the key pollination stage. This is a high moisture usage period, demanding extra-heavy rain for the best yields. Soybeans also have undergone a slow and steady decline, as soybeans began blooming and more recently started setting pods. Nationally, corn and soybeans lost 4% in the good-excellent category and gained 3% in poor-very poor over the past several weeks. Thirty five percent of crops are in serious jeopardy from drought.
The Eastern Midwest has not been heavily affected by drought preserving a good yield potential in Ohio, Indiana and eastern Illinois.
The U.S. Drought Monitor August 6 showed "abnormally dry" to "severe drought" in Nebraska, Iowa, southwest Minnesota, northern Wisconsin and Missouri. Midwest growing conditions are much drier than a month ago. The slow but steady decline in soil moisture has been especially detrimental in corn as the yield-sensitive "silking" period occurred under dry conditions. Soybeans have a better chance to turn around, if conditions turned wet, as the crop is moving through the pod setting stage. Heavy rainfall is a big yield booster encouraging larger seeds in the pods.
North-South Rainfall Extremes
While Midwest drought has worsened, flooding has developed in central Great Plains and Mid South due to moist air stream from the Southwest Monsoon. Wichita, Kansas , has received 15 inches of rainfall in the past month, compared to 2.8 inches normally. If there is problem with Kansas wheat planting this fall, it would be too-wet field conditions. Corn and soybeans in the Mid-South have benefited from a cool and rainy summer. However, relentless rains are becoming too much of a good thing.
However, both Midwest drought and southern flooding have become extreme. We expect to see reduced ratings in corn and soybeans in the August 11 report from USDA due today.
Weather Forecast Highlights
A weak cool front triggered showers overnight in a thin band of the Midwest. Rainfall amounts were mostly traces to .20 inch. It would sink southward through the Midwest and Mid South the next 36-48 hours eventually stalling in the southern Great Plains-Gulf states. Cool dry Canadian air would take over the Midwest reducing both humidity and temperatures. Central Illinois would go from mid 80s F today (near average) to mid 70s F Wednesday (10 F cooler than normal). Cool high pressure would dominate the Midwest through Friday before warming resumes on the weekend.
The GFS model does not see much rainfall in the Midwest forecast. A horizontal front is expected to stall out in the Southern United States from central Texas to the southern Georgia, blocking Gulf moisture from streaming up into the Midwest farm belt. Low humidity would provide an unfavorable environment for showers most of the week. By Friday-Saturday a modest risk of Midwest showers is projected, 35-45% risk of rainfall.
A major change in the weather pattern is expected in the 6-10 day outlook, indicating strong Midwest warming but though still not much rainfall.