Regarding weather, the primary attention grabbers as March draws to an end are the potential for flooding in the Ohio and mid-Mississippi river basins, the dryness in the upper Midwest and Plains, and any potential effect that might be seen from El Nino. However this spring, there is little consensus about how the weather will shape up.
As the map above shows, “the precipitation from Arkansas to Ohio was twice to three times normal in the first half of March,” according to Elwynn Taylor, climatologist at the University of Iowa. “As the days become longer, the weather patterns migrate north. If March is wet in Arkansas, it often is wet in Iowa during planting season.”
This also is one of the top weather issues Evelyn Brown Garriss sees: “The combination of cold, the high risk of flooding in lower areas along the Ohio and Middle Mississippi rivers could delay planting. Early corn planting in the South already is delayed due to rain.”
Brian O’Hearne of eWeatherRisk, a private weather insurance company, puts dryness among his top concerns, noting the current similarities with this time in 2012 on Drought Monitor maps. While no one is predicting the season will develop the same way 2012 did, it certainly is something to keep an eye on.
Some years, low pressure in the Gulf of Alaska remains stationary and results in a dry pattern in the Western Corn Belt, Taylor reports. “In some cases, the pattern has lasted for more than six weeks and up to 12 weeks (1988, 1989 are examples).
However, the reading on current soil conditions vary depending on which type of map you view. “Subsoil moisture is good for most areas of the western Corn Belt,” Taylor argues. “Eighty percent of tile lines were reported to be running in the fall. Most areas that didn’t receive sufficient rain to restore subsoil moisture inAugust did so in September or October. It only takes an inch or so of rain to moisten topsoil down to the moist subsoil.”
The Climate Prediction Center’s long-range forecasts for March-May indicate the Corn Belt and northern Plains have equal chances for above normal, normal and below normal temperatures. Texas, Oklahoma, Arkansas and the Delta are likely to be below normal. Moisture also has equal chances through most of the heartland, though west Texas, up through the mountain states and as far west as the Nevada border, are expected to see above-normal precipitation.The CPC’s summer forecasts also assign equal chances regarding moisture and heat in the Midwest. It is not correct to say this means a normal growing season: It means the scientists don’t know; there isn’t a strong factor suggesting excessive wetness or drought.
Role of El Nino
El Nino has arrived, but little influence is expected as it was too late in the season to improve snow pack. The March 9 declaration of its arrival was almost exactly a year from when the National Oceanographic and Atmospheric Administration issued an El Nino watch (for 2014). The odds of the episode lasting through summer are 50%-60%, according to NOAA. Although this episode is weak, some impacts, such as wet weather along the Gulf coast, are possible, NOAA says.
“A weak El Nino, supplemented by favorable conditions in the North Pacific Ocean may be sufficient to qualify 2015 as an “El Nino growing season,” Taylor says. “Such seasons have a 70% chance of the U.S. corn yield exceeding the trend, which is 160.3 bu./acre.” Taylor’s current estimate: 166 bu./acre.
El Nino’s impact on the monsoon season in India is garnering interest but the consensus is that odds favor a normal one because the Indian Ocean Dipole, is neutral. Should El Nino intensify or the IOD turn into a negative influence, then this major export competitor might experience a reduction in its monsoons.
The next update on El Nino will be released April 9.