While it may seem like there has been many tornadoes and much severe weather as of late it is actually not unusual.
For example, in 1989 a tornado outbreak put down 4 tornadoes in New York and around 16 in the entire northeast.
How about a short article about the "Great Windfall of 1845" from the Adirondacks: http://goo.gl/0yXnWc
I made a blog post about a gigantic tornado that struck Poughkeepsie, NY back in the late 1700s: http://goo.gl/D9vY0n
Here's an article about a terrible tornado in 1856 in northern NY: http://goo.gl/RqUzHp
Here's another article from the New York Times about a "terrific" tornado that struck Poughkeepsie in 1863: http://goo.gl/oQbH9j
From 1953 until 2013 there were 411 tornadoes in New York State with 26 deaths. Most of these tornadoes took place in central NY and the Hudson Valley; however, the tornadoes occurred in each geographical region of the state. A mountain may hinder a tornado, but it will not stop it all the time. In May of 1952 an F2 tornado struck just southwest of Whiteface Mountain in the Adirondacks. Whiteface is over 4,500 feet tall.
Lowville, NY was just hit with a tornado on Tuesday. The town is no stranger to tornadoes. In 1987 an F0 struck the town (I remember seeing a mountainside with a streak of trees broken for years) while just a couple dozen miles to the west and south there have been F1 to F3 tornadoes.
I strongly suggest checking out http://www.tornadohistoryproject.com/tornado/New-York/map to learn more about these tornado statistics in New York State.
Remember, technology and media have both grown over the past 50 years. A small tornado in the middle of nowhere may not have been reported in the early 1900s but today our radars and satellites can see anything anywhere. The media loves to talk about tornadoes hitting places where you may think "tornadoes can't happen" but please understand that tornadoes can happen ANYWHERE.
So, as far as tornadoes are concerned, this is unfortunately relatively normal.