If you look at the tables on that site, the figures do show quite dramatic drops in snow in Bansko year on year. I remember our first year there in 2004 and 2005 the seasons were incredible with snow from Nov-April. I can guage it against the home run in Bansko, 2004 & 2005 it was open 90% of the season, the last few years it has been closed most of the season. The lower slopes and the town seems to get less and less each year.
Last year Bansko panicked dramatically as the opening loomed on the 15th and no snow, but it turned out eventually.
Can't see today as the Bansko webcams tend to be turned off until it snows. Last year they showed an old snow laden picture which many people complained of when they arrived to find no snow.
Borovets is great lumps of snowcannon snow only, and Pamps looks good for planting veg.
Then again, if you look at the year on year pics from www.bulgariaski.com
they do show little snow until late Dec.
With Vitosha threatening (again) to stay closed for this season, this should be an interesting season in BG.