The talk amongst weather forecasters right now is that the strongest El Nino in nearly 20 years will affect air circulation patterns aloft. That should deliver a warmer, drier winter to Indiana, because all weather forecasters know that is what El Nino winters do.
Ken Scheeringa, associate climatologist in the Indiana State Climate Office, points to information that says that while's that's usually true, it's not always true!
There have been six El Nino events since 1950, not counting the one currently under development. The two strongest before this year were in 1982-83 and 1996-97.
The deviation in temperature from norm for the entire winter for ; 1957-58, 65-66, 72-73, 82-83, 97-98 and 2009-10 were -1.4, -0.5, 0.3, 4.6, 6.0 and -3.1 degrees F, respectively. That's right, three of the six actually resulted in winters that were cooler than normal. However, note that the two very strong El Nino years were much above normal for temperature across Indiana.
What about precipitation and snowfall for the same years? All were below normal, but some much more so than others. Here are the differences, measured in inches of rainfall, after conversion of snow to rain quantities. The precipitation deviation for norm for the same six winters in inches of rain was: -0.05, -1.32- -1.20, -0.50, -1.22 and -1.98, respectively.
Note that while the two strongest El Nino events in the past 65 years produced less moisture across Indiana than normal, the driest winter by far was 09-10, the same winter that was cooler, not warmer, than normal!
Bottom line? We're not sure, but it would appear the odds favor a warmer than normal, drier than normal winter- maybe!