I assume that you're referring to Freeview reception. If so, you've correctly identified the problem as the aerial system not being up to the job. There could be a number of possible reasons why it used to do the job but it now doesn't.
Firstly, as you've realised, it could simply be that the aerial has been knocked out of alignment by the recent high winds.
Secondly, the rain which has accompanied those winds might have resulted in water ingress into the aerial connections.
Additionally, there are a number of other possible causes. See here:
http://www.theanswerbank.co.uk/Technology/Ques tion532302.html
Start by taking a look at the alignment of the aerial and comparing it with the aerial on neighbouring properties. If you can't see a problem, it's probably time to change the aerial system. (NB: By 'system' I mean both the aerial and the cable). This is the most frequently recommended, and praised, aerial here on AB:
http://www.maplin.co.uk/Search.aspx?criteria=P T18U&DOY=28m3
Chris