I may have sneaked but I have never snuck.
In fact I had not heard of the word until fairly recently. Now it is cropping up everywhere.
I read this the other day: "Sneaking out of school was near impossible, but I pulled it off. And I snuck back in to prove it."
Admittedly that was in a US article, where the usage originated. It was introduced there, as an alternative to 'sneaked', as long ago as the late 19th century.
It is another Americanism that is being rapidly adopted in the United Kingdom!
However, it is not universally accepted in America and style guides at some of the biggest newspapers in United States and Canada - including the Globe and Mail (1998) and the New York Times (1999) - banned 'snuck'.
But things seem to be changing. President George W. Bush in his 2008 State of the Union address said:
"The people's trust in their government is undermined by congressional earmarks — special interest projects that are often snuck in at the last minute, without discussion or debate."
There is a helpful summary in 'The New Fowler's Modern English Usage' :
sneak (verb) Its origins are shrouded in mystery ... From the beginning, and still in standard British English, the past tense and past participle forms are sneaked. Just as mysteriously, in a little more than a century, a new past tense form, 'snuck', has crept and then rushed out of dialectal use in America, first into the areas of use that lexicographers label jocular or uneducated, and more recently, has reached the point where it is a virtual rival of sneaked in many parts of the English-speaking world. But not in Britain, where it is unmistakably taken to be a non-standard form.
So, I shall never use it - like 'Train Station' (American). The English is "Railway Station". It annoys me that my local council has, at considerable expense, replaced several of the original English direction signs around town with the American version.
What next? The favourite Edith Nesbit book, "The Railway Children", re-titled "The Train Kids"? - or worse "The Railroad Kids".
LissaT
Pro 
I don't believe that snuck is American. We have come to accept that a southern form of English is the true correct English, but here in Lincolnshire - and I believe throughout the north-east - we use (well, not me personally as I 'talk posh') what a friend once described as the Norse strong verb. This covers such things as snuck rather than sneaked, tret rather than treated and lit rather than lighted, as well as I was sat or I was stood rather than I was sitting/seated or I was standing. As the English language standardised on both sides of the Atlantic in some cases the words and grammatical forms from different dialects became those in standard use which is just one of the reasons why in America the past perfect of dive is dove and in England is dived, but on both sides of the Atlantic the past perfect of drive is drove and only toddlers say drived. There's no logic to any of it, and we should just embrace the richness and diversity of our wonderful language - and never ever seek to update the literature of the past, but enjoy it in all its idiosyncratic richness even long after certain words have gone out of common currency (which in the case you quote, whatever your local council may choose to believe, they haven't).