With the first measurable snow of the 2012-13 winter season two or three days away, we can be reasonably sure that the number of days that will have elapsed since the last measurable snowfall of winter (February 25) will be near 300. To be exact, it will be 298 if the approaching winter storm drops a widespread 1" or greater accumulation before midnight Thursday/Friday, or 299 if that first inch doesn't fall until after midnight. Either scenario is possible, depending on the exact track the disturbance takes when it arrives. A little more northward means more rain and a later start for the snow; a little farther south for the track and the snow will begin a little earlier. For now, if I had to bet, I would say the first inch will be on the ground before midnight.
Regardless, the number of days between measurable snowfalls this year is quite a bit higher than the highest number so far since 2000 (280 days, in 2010), and is about 25% higher than the average number of days between measurable snowfall from 2000-2012 (239). A look at our weather records going back to the year 2000 shows the latest winter/spring snowfall of 1" or more on April 24, 2005; the earliest "last snow" was this year, February 25th. The latest "first snow" is -- as you might expect -- this year, by far. Before this year, the latest first snow was 2001, occurring on December 14. Interestingly, the remainder of that month was extra snowy; 27.5" inches of snow fell during the last eight days of the month!
As noted earlier, this year's gap between snowfalls is easily the longest since 2000, at 298/9 days. The shortest gap happened in 2006, when just 188 days elapsed (April 6 to October 12).
A list of the number of days between snowfalls by year:
2012: 298/9 (TBD)