.... I'm not sure if you're asking for general comments on what Polar
Lows (or depressions) are, or this specific case but there is a Q/A in
the FAQ which on review seems to be still relevant (though written
many years ago now).
I do know that in very recent years some intense research has been
done with published results on these features, so a search on the net
might bring these ideas up to date.
The FAQ entry is he-
http://weatherfaqs.org.uk/node/95
Martin.
--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023