Plant closing and notice period questions - 7 months and counting

My employer announced that the site will close and gave us written notice. I do not know if I should start looking now or wait for severance news. Has anyone been through this?

Thanks for writing this out. I went through something close to it 7 months ago, and it got easier once I kept a simple log of every call and form.

Start your search early. I wish I had begun the day of the notice.