A nor'easter announces itself in Albany hours ahead of arrival — the sky over the Hudson turns the color of an old nickel and the wind swings hard to the northeast. By the time it's coming down sideways on the Madison Avenue hill, the plowing is already underway. Snow removal here covers driveways, private lots and walkways, with salt and sand for the Center Square stoops and slopes that turn treacherous first. The hills west of downtown are steep enough that a half-cleared drive is worse than one never touched. Full width, curb to garage door, finished before anybody has to test that grade: that is the measure the storm gets judged by.