Storm rolled through, S/N ratio went up

So this is strange. I've had the 12/1 IPDSL product for two years now. My downstream S/N hoovers right around 7.0 normally -- but the connection is stable. Last night around 2AM a bad storm rolled through. Power went out for a bit. Lightning everywhere. When modem finally synched back up it was now reporting a S/N ratio of 11.7 occasionally jumping to 12.6. That just seems the exact opposite of what I'd expect...