SNR Margin and the weather

[#1]

My SNR margin was reset last Tuesday by Adam (many thanks) to allow me to get back to a  downstream synch of 8128 - everything was good for ~ 4 days with the SNR holding at 7.3 +/- 0.3 dB as measured by Routerstats.
However yesterday it all went to pot ,firstly during thundery weather (understandable!) and then majorly overnight in the high winds when I experienced at least two reconnections as the SNRM danced around and dropped as  low as 1 db.
It has now appears to have settled down @ 8.3 SNRM with a synch of 8032
I don't have any overhead lines between my house and the exchange so why did I see so much noise on the line overnight (compared with previous nights)?
Surely underground lines shouldn't be affected by wind (flooding I can understand!!)

[#2]

Further to the above, my Routerstats graph of downstream SNRM appears to be an almost perfect record of the strength/blusteriness of the wind since Sunday afternoon!
I've walked my estate and there are no overhead lines, altho' there are in older parts of the "village". Is it possible /likely that the "green" cab. serving my phone line would be connected back to the exchange by overhead line,or are these always connected by underground cable?

[#3]

Hi davidj60,

Quote

Is it possible /likely that the "green" cab. serving my phone line would be connected back to the exchange by overhead line

That's always a possibility. It could also be that the wind is forcing water into a joint somewhere. A tough one to diagnose really.
Jojo