According to the latest maps above from the National Oceanic and Atmospheric Administration’s Climate Prediction Center, Indiana has a 40% chance to see above-normal temperatures for April.
Some people question why long-term forecasters say it will likely be warmer than normal, and then put the chances at 40%. Think of it in terms of daily forecasts. If a weatherman says there’s a 40% chance of rain while you’re planting, you will likely bring along a tarp to cover up the seed tender or sacks in the truck — just in case. If you’re going to town, you would probably grab an umbrella on your way out the door.
What the forecast is saying is that the best guess is leaning in that direction, even though it’s not a sure thing. When the weather forecasters can’t pick up a signal that indicates that the trend will likely go one way or the other, they simply say there are equal chances of above-normal, normal and below-normal temperature or precipitation, as the case may be, says Kenneth Scheeringa, Indiana associate state climatologist.
For precipitation, there’s an equal chance that Indiana will be at, above or below normal in April, he notes.
Predicting shorter-term forecasts can be difficult during a transitional month. April is a continuation of the transition from winter to spring that starts in March. If predicting short-term forecasts are difficult, predicting long-term trends can be even tougher.
Here’s a true story. A reporter was visiting a seasoned climate expert, Jim Newman, in his office at Purdue University many years ago. On the way to West Lafayette, the reporter heard on the radio that there was only a 10% chance of rain that day. There were clouds, but nothing threatening.
After talking with Newman for a while, the reporter offered to take him to lunch. Newman reached behind his door to grab an umbrella.
Puzzled, the reporter told him he just heard there was only a slim chance of rain. Newman just smiled.
Sure enough, walking back from lunch, a cloud opened up and it rained. Newman looked at the reporter, opened his umbrella, smiled again, and asked if he wanted to share it.
Apparently spring forecasts are too fickle for even seasoned weathermen!