Latest from National Weather Service:

LOOKING BACK AT THE BIGGEST STORM OF RECORD FOR WASHINGTON DC... THE JANUARY 1922 KNICKERBOCKER STORM...28.0 INCHES OF SNOW WAS
PRODUCED FROM 3.02 INCHES OF LIQUID WATER.

CURRENT FORECASTS FOR THIS EVENT HAVE TOTAL LIQUID FALLING FROM THIS STORM APPROACHING 3 INCHES...WHICH ACCORDINGLY WOULD CREATE A SNOWFALL THAT WILL RIVAL THE KNICKERBOCKER STORM TOTAL. GENERALLY ACROSS THE REGION...20 TO 30 INCHES OF SNOW WILL FALL BY SATURDAY EVENING.