Hard to say....3" of sleet sounds high, though not impossible. I think we'd need to have the BL cool by about 10-11Z to have that much.....it would take at least 1 inch of QPF to get 3" of sleet, and 3 to 1 is kind of aggressive for sleet ratios, though by the time we get -10C in the cold layer, the sleet ratio would become higher because of pixie dust probably mixing in....but before that, it's going to be IP/ZR mix and that will have ratios well below 2 to 1.