One 2011 factor that is not present going into 2012 is the intensity, based on the water temperatures. It was 3 degrees below normal last year and only 1.5 degrees below normal this year. We are in a weak La Nina, compared to the strong one of 12 months ago. Last year the jet stream was also active and winter storm activity was concentrated, but the jet stream has recently split. That will pull moisture into the northern plains from the Pacific, instead of the Gulf of Mexico.
For the February to April period, below average moisture will occur across the southern tier of states, bulging into the southern Plains. Above average moisture will occur from the Mississippi River eastward to Ohio. The Dakotas will have equal chances of above to below normal precipitation.
For the March to May period, above average moisture will remain in the northern tier of states, with below average moisture in the southern Plains and across the Deep South. Average moisture will occur in the Cornbelt from Iowa and Missouri eastward to Indiana, with above average moisture in Ohio, once again.
Dutcher says the forecast for spring suggests the eastern Cornbelt will remain wet with planting delays and possible flooding in the Ohio and mid-Mississippi River valleys. He says there is currently enough reservoir space to handle normal to slightly above normal snowfall, without major floods, but if snowstorms increase, that could change.
For the second consecutive winter, the Cornbelt has been under the influence of a La Nina, but this current system is not as intense as one year ago. While significant portions of the western Cornbelt are entering the winter with subsoil moisture at relative low levels, some recharge may be forthcoming. The eastern Cornbelt will remain wet again in the spring of 2012, with potential for more planting delays and flooding.
Source: FarmGate blog