It's very difficult to place these lake-surface temperatures in a long-term context. The satellite record is fairly short, and most of the long-term observations are from Saltair a single location on the south coast. Nevertheless, if we look at the lake-surface temperatures from Saltair for 1972–1988, we find that 15ºC is near or above the upper margins of the range for November 1 (data is bimonthly).
|Source: Steenburgh et al. (2000)|
Will that mean a big lake-effect storm? It really depends on whether or not the atmosphere decides to cooperate.