Yes, Sunspots.
This is very important for weather patterns. It has been know for 100 that weather is more variable during sunspot minimums and sunspot maximums. There were some much older observations about sunspot pattern and wheat production.
We are just moving out of the longest, quietest and deepest sunspot minimum in my lifetime. Texas has had the worst drought in recorded history of weather here. No one living has seen so low annual rainfall (October 2010 to October 2011 rainfall was 2.5-2.9 inches in this county, average rainfall is 25 inches) nor so hot temperatures.
We have recently seen that change (as the sunspots are returning), one evening we had 3.9 inches of rain and about 2 weeks later we had .9 inches.
... and let's not forget those oh, so volatile transistion phases!