Hi Andrea and thanks for your question and great pictures of your fir tree. It looks like the tree is losing needles from the inside out which is a normal process, as the older needles are shed first when a tree replaces needles. However, it's a little early in the season, and your tree seems to be losing a LOT of needles.
https://extension.oregonstate.edu/news/conifers-naturally-shed-needles-summer-fall

You could get an opinion from an ISA certified arborist who will come and look at the tree to see if there is something else going on such as an insect problem or disease. They should not charge to just come look and it would be worth getting several opinions. You can find someone at the following website:
https://www.treesaregood.org/findanarborist

That being said, if you want to wait a bit, since the rest of the tree looks very healthy, be sure to give the area a good soaking every couple of weeks this summer and keep an eye open for other signs of problems such as insects or odd deposits on the branches.

It's a beautiful tree, so good luck!