When Ken Scheeringa prepares to give insight into what type of weather you can expect for the upcoming month, he looks at long-range forecast maps. They are prepared by the Climate Prediction Center, a division of the National Oceanic and Atmospheric Administration.
Scheeringa is an associate state climatologist in Indiana. He notes that the Climate Prediction Center issues maps and makes predictions based on what it anticipates is coming. If there is no major feature developing in the weather pattern, sometimes all the forecasters can say is there is an equal chance of normal, below-normal or above-normal precipitation or temperature, whichever the factor might be.
Many of the forecasts over the past several months have favored warmer-than-normal temperatures and equal chances for normal, above-normal or below-normal rainfall, Scheeringa notes. One reason the forecasts haven’t been more decisive is because no major factors that influence weather in Indiana, the Midwest and around the world have been active. The El Nino-La Nina cycle, sometimes referred to as the ENSO cycle, has been in a neutral phase for several months, and is likely to continue in that phase through winter, Scheeringa notes.
That means other factors that can influence weather will play a bigger role. For some, it’s not as easy to predict how they will impact weather as with the ENSO cycle, whether it is in El Nino, the warm phase, or La Nina, the cool phase.
For October, the best guess is that temperatures will average somewhat above normal, Scheeringa says. However, this doesn’t mean there might not be a cooler week or stretch of days embedded within the warmer trend. Cold outbreaks and light or even hard and killing frosts are very difficult to predict in advance.
Most of Indiana is back to equal chances for normal, above-normal or below-normal precipitation in October, he adds. A small piece of southwestern Indiana is in a bigger band coming out of the Southern U.S. that might see above-normal precipitation. However, it’s rated at only 30% odds of being wetter than normal, Scheeringa concludes.