We really don't have to go back too far for a decent March snowfall in Manhattan itself. Though rare, 8.4 inches fell March 21-22 2018, 7.6 inches on March 4, 2017, and 7.5 inches on March 5, 2015. For a truly large snowfall in March though we have to go all the way back to 1888 in Manhattan where 16.5 inches fell. So I won't write it off yet, it is really produce or shut up time for the year now. If it is rain then the snowless streak of Central Park having 1 inch or more snowpack will hit a massive record before we see snow again.