The big question for this spring revolves around how quickly Indiana can shrug off La Niña and return to El Niño-Southern Oscillation (ENSO) neutral conditions. Until that happens, the likelihood of a wet spring remains high. The national Climate Prediction Center (CPC) provided new guidance for the spring now that we are quickly approaching the beginning of the meteorological spring season.
Prominent in the latest guidance is a prediction of above-average precipitation over the eastern Corn Belt. On a map, the trend looks like a bullseye with Indiana in the center. Meanwhile, predictions for the eastern half of the United States are favoring above-average temperatures in March, April and May. This warmer, wetter, early-spring trend is associated with an extension of wintertime La Niña conditions, focusing the moisture on the front half of the three-month period.
Experts at the CPC say that regarding ENSO there is relative confidence that La Niña will remain in place throughout the spring, with a transition to ENSO-neutral conditions beginning in May. With this transition, less predictability in the long-range forecasts exists and the possibility for the wet signature to fade increases towards the end of the planting season.
The warming signature, according to CPC, is trending two-thirds of a degree warmer than normal over the period, which does not seem like much. However, parsing that guidance a little further, the CPC gives Indiana a little less than 15 percent chance of having a top ten percent warmest spring, with only a five percent chance of a top ten percent coolest spring. In other words, Indiana has a one in seven chance of a very warm spring and a one in twenty chance of a very cool spring.
The wet signature varies across the state, with southern Indiana expected to have more extreme wetness than northern Indiana. The predicted anomaly is 1.35 inches above average in the south and 0.83 inches above average in the north. Once again, due to the La Niña, that deviation towards wetness is likely to be felt more greatly in March than in May. CPC guidance gives similar odds for wetness as temperatures. Indiana has a one in seven chance of a very wet spring and a one in twenty chance of a very dry spring.
As we look forward to getting outdoors and farmers begin to work ground, we may initially have limited windows where soils are dry enough to do anything, but those windows look to grow longer towards the end of the spring. For more information, please contact the Purdue Extension office in Posey County via hschmitz@purdue.edu or 812-838-1331.