Chinook winds and warmth in Fairbanks eliminated the remains of the valley-level winter snowpack on Saturday, with the official daily snow depth measurement dropping from 5" to only a trace in a single day. The last time this much snow was removed in one day was in April 2004, and for context the record 1-day decrease is 8" on several occasions (most recently April 24, 1993). Snow removal of this efficiency is accomplished by sustained winds that allow for large heat transfer to the snow surface.
The April 18 end of the winter snowpack is 5 days earlier than the long-term median date and just barely falls within the earliest tercile of melt-out dates; so it is earlier than usual but not very much so. The earliest melt-out in Fairbanks was on April 3, 1970, although in that year snow returned the very next day; there was a more abiding melt-out on April 6, 1965.
Is this the last of any snow cover in Fairbanks until autumn? Not necessarily. Almost half of all years see some accumulating snow after the first melt-out date, although only 20% of years see an inch or more of snow depth reported. More than 1 inch of reported snow depth is rare after melt-out, so any snow that accumulates from here is very likely to be light and/or short-lived.
It's interesting to observe that the chinook warmth has also done a number on river ice in the area, and the tripod at Nenana is on its last legs (see below). If the clock is tripped today, it will tie the all-time record for earliest breakup date (1940, 1998). It's a remarkable turn-around from the cold spring and record late breakup of 2013.