One thing about winter severe weather events I have noticed is that the strongest storms aren't able to thrive right in the "belly" of the low. In other words, there needs to be some space from the surface low. For example, if I remember correctly, during the January 24, 1997 tornado in Tuscaloosa, the surface low was up in Missouri...not really sure there is anything to that rule, just something I have noticed over the years.
That's honestly the case in most of our bigger severe weather events, even during spring and during the warmer part of fall.