I wouldn't necessarily compare Nemo to Katrina (at least at this point), but serious winter storms can be deadly. Heavy snow and ice can accumulate and bring down limbs, ripping down power lines. Our daytime temps here have only been in the single digits and the mercury dips to -5º to -10º F at night. In these frigid conditions you don't want to go for too many days with no electricity because even the motor in your oil-burning furnace needs electricity. A house can get pretty cold.
There was a bad snow/ice storm in Maine in the mid-90s (I think it was then) that friends told me about. EVERYTHING got coated with 2-3 inches of ice. Utility poles snapped and miles and miles of power transmission lines came down. Also, those gigantic metal towers that carry the transmission lines could not take the additional weight and collapsed. They did not have power for two weeks. Luckily, they had a wood furnace and wood stoves in their home.
It is so cold up here that the snow is very fine rather than wet, clumpy, and heavy. If that is the case, this 'lighter' snow will probably not accumulate in amounts heavy enough to break limbs to cause power outages. However, winds are expected to be very high all day long Saturday, and those winds
may be the culprit in bringing down power lines.
... And Boston may get 2' - 3' of snow. Woof!