Ag Weather Forum

Slow Harvest Stays in Forecast

Mike Palmerino
By  Mike Palmerino , DTN Senior Ag Meteorologist
The European forecast model's presentation of upper-air low pressure in the southwestern Plains indicates more Gulf of Mexico moisture to flow into the central U.S., for more precipitation to interfere with harvest through the end of October. (Tropical Tidbits graphic)

Latest crop progress reports continue to show a substantial lag in progress. Corn maturity and harvesting are running from 10 to 14 days behind normal. Soybean maturity is from six to 10 days behind normal, and soybean harvest is from five to 15 days behind normal. In the state reports, corn maturity is well behind average in Michigan (62% versus 89% normal); North Dakota (65% vs. 93% normal); Ohio (72% vs. 94% normal); South Dakota (74% vs. 95% normal); and Wisconsin (61% vs. 88% normal).

Nationwide, the corn harvest rate of 30% finished is the slowest in the past 10 years, since the late harvest of 2009. Back then, harvest going into the final 12 days of October was measured at 17% finished.

The forecast in the next 10 days keeps the unfavorable combination of chilly weather and periodic bursts of precipitation in play over the central United States, especially in the Northern Plains and western Midwest. A trough of low pressure is expected to remain between the Rockies and Mississippi River. Disturbances within this trough, combined with Gulf of Mexico moisture being fed by a ridge over the eastern U.S., make for a wet pattern.

The only question about this pattern is the position of the trough. The European model, which has become almost exclusively the model of choice, has the trough more over the southwestern Plains, while the U.S. model places the trough closer to the Great Lakes. The U.S. model generally likes to strengthen troughs and weaken ridges more than what actually occurs. The European model is the wetter model for the area of greatest concern. The U.S. model would be drier and much colder.

Winter wheat planting in the Southern Plains is running at near normal levels and is more than 75% complete. Soil moisture conditions are much lower than they were a year ago when they were adequate to surplus in the major producing areas, but are not dry enough yet to put any significant stress on the crop. Near to above normal precipitation is possible with this pattern during the six-to-10-day period.

In Brazil, very timely and beneficial moderate to heavy rains occurred in Parana and Mato Grosso during the past 24-48 hours. This should increase planting progress which is running behind normal and ease stress to the early-developing crop.

Central Argentina rainfall has been limited during the past week. However, with low temperatures, planting remains behind normal. There are indications of some significant rainfall in the major corn and soybean areas during the weekend into early next week, which would improve conditions for planting and developing crops.

The latest run of eastern equatorial Pacific Ocean sea surface temperatures shows a departure of 0.2 degree Celsius above normal for the first half of October. This is up from the minus 0.4-degree departure observed during the month of September. All you can say about sea surface temperatures at this time is they are showing high variability around normal levels.

Mike Palmerino can be reached at



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