Ag Weather Forum

Flooding Possible From Upcoming Heavy Rains

Mike Palmerino
By  Mike Palmerino , DTN Senior Ag Meteorologist
Heavy rainfall this week on already-saturated soil will probably go directly into the rivers. (DTN graphic)

Heavy rains in the southern and eastern Midwest and Delta states at the end of the week could initiate flooding.

With expectations of 1-3 inches of rain over the south-central United States later this week, the potential for flooding exists.

Soils are already saturated and there is little vegetation at this time of the year to transpire the moisture. This means that most of the rainfall will go directly into the rivers.

An active precipitation pattern is expected to continue over the southern and eastern Midwest through at least the middle of the month if not longer. The northwest Midwest and Northern Plains are expected to miss out on most of the significant precipitation during the next seven to 10 days, sparing them from flooding or a building snowpack.

For the foreseeable future, virtually any significant precipitation falling in the Midwest and Northern Plains has to be considered a negative as it just increases the risk of fieldwork and planting delays in the spring. A turn to colder weather is expected next week in the Northern Plains and northwest Midwest, and not as cold to the south and east.

We have seen some significant precipitation in the Southern Plains during the past two weeks help recharge soil moisture. Some additional beneficial precipitation for winter wheat is possible during the next seven to 10 days improving soil moisture for the crop when it breaks dormancy in the spring. There are no indications of any severe cold affecting the region during the next seven to 10 days.

There are mostly favorable conditions for filling soybeans in the major growing areas of Parana and the Mato Grosso Brazil. We have seen a significant improvement in the rainfall pattern in northeast Brazil during the past week. However, hot and dry weather during the month of December should allow reduced production. The area having stressful weather at this time is the southern state of Rio Grande do Sul. Hot, dry weather is stressing developing soybeans which are in vegetative growth. Also, pollinating corn is being affected with some crop losses expected. There will be episodes of scattered showers and thunderstorms in Rio Grande do Sul beginning Thursday and continuing into early next week. If any of this rain is significant, it will ease crop stress and put the crop back on track as it has not yet begun to fill.

Significant rainfall was reported in the dry areas of central Argentina (Buenos Aires and La Pampa) during the past two weeks. Most corn and soybean crops are in good shape at this time. The absence of any hot weather due to increased soil moisture also benefits crops.

Our latest calculation of the sea surface temperature in the eastern equatorial Pacific Ocean for the month of December 2019 was plus 0.9 degrees Celsius above normal. This compares to the plus 1.0 observed during the month of November. We continue to feel we are in a weak El Nino pattern, as reflected in the characteristics of the weather patterns observed in the U.S.

Michael Palmerino can be reached at



To comment, please Log In or Join our Community .