Question
Over the past 2 years our weeping cherry tree has been showing less and less blooms in the spring and less leaves in summer.We pruned several dead branches that have shown no new growth.Last weekend after a hot day a severe thunderstorm came through and after the storm there were hardly any leaves on the tree and the next day all the leaves that were left were brown.This basically happened over night.The tree may have been planted in the 70's when our house was built, we have only owned for 3 years.Should we have this poor old guy cut down?

Answer
Sounds like a blight disease. If you take you finger nail or a small knife and scrape a small bit of the bark off a branch and it is green under the bark at that point on the branch the tree is still alive. IF you find brown or not green then the branch at that point is dead. If you find brown go lower down on the branch until you find green--if no green is found then the branch is dead. Try other limbs until you find green If you find green I would prune off any dead branches, fertilize, mulch and water.  But it sounds like the tree is dead. Sorry!