Hello, We have a very large old oak tree in our yard that seemed to be very healthy as of two weeks ago but today I noticed that a good 70% of the tree is brown. We have experienced severe weather within the past month with tremendous amounts of rain and lightning. There does not appear to be any burn marks on the tree from a possible lightning strike, could the rain play a role? Could the tree be going dormant? Our house is 9 years old and the tree is some 60’+/- east of the house and roughly 80’ to 100’ tall with a 70’to 80’ dia drip line. What would cause an old, well-established tree to brown up so quickly?