Assuming the chart is correct, and looking at the temps forecast for New Castle on Accuweather.com for today, tomorrow, and Friday, here is how it should pan out assuming a skim to start with:
Wed. High 33 Low 15 Avg 25 = .8 from a skim
Thurs. High 26 Low 10 Avg 20 = .6 from 2", total 1.4"
Fri. High 22 Low 9 Avg 15 = 1.4" from 2", total = 3.4"
I rounded up or down for the average to meet the chart. I also used 2" for Thurs. when the chart actually showed .8 from Wed. so that is conservative. With any luck, and assuming the chart is correct (and we all know what happens when we assume!), there should be somewhere close to 4" where there was open water around the edges. This doesn't take into accout any wind. If it's 3" of new, clear, solid ice, I would think you should be able to get out to the thicker ice without much trouble.
Just some number crunching and speculation on my part. I don't have enough real life experience to recommend anything to anyone.
... and there is no such thing as safe ice!!
-Jeff