I've done a search and I couldn't find anything that seemed to relate to my problems. I assume this is one of the 1.6 problems so any insight would be highly appreciated

Basically whenever I'm outdoors and I go to a place with a lot of snow, fog or rain, my computer goes nuts. I get a moderate FPS drop from my computer straining to cope, and I've no idea why this happens. Deleted all my mods, turned my settings down from Ultra to low even though I've been running Ultra since around December with no problems at all. These issues more or less happened overnight which is why I assume its related to the latest patch. I can't comfortably play Skyrim knowing my computer is most likely about to overheat!
I also have the same problem with dragon fights. Strangely enough, I don't get any problems until after the dragon has been defeated. It happens the second I absorb its soul and I stand around the skeleton. Just looking at it will make my computer get extremely loud and hot.
Anyone have any thoughts as to what might be causing this or things I can do?
My specs are as follows if it helps:
Windows 7 64 bit
Intel i7 2600k CPU
nVida Geforce GTX 460 GPU
Corsair 8GB RAM
2TB HDD
Coolermaster HAFX case with power supply
And as I said I've been running Skyrim on ultra settings with mods for some time now, on a very smooth and consistent FPS with absolutely no problems at all aside from maybe turning shadows down to medium to reduce interior stuttering.
If I've missed anything let me know.
