I agree with the desensitization suggestions. You might also try Clomicalm, it's like a Glade plug-in but is supposed to calm animals down.
Also, and you probably already do this, ignore the behaviour. Reassuring is the same as rewarding to a dog, and makes the problem worse.
My old Bloodhound hated storms, probably because she was kept outside before I adopted her. She would pace and drool and whine, but luckily not climb on my head. I'd just ignore her and eventually she would find herself a safe spot under a desk or behind the sofa until it was over.
Also, and you probably already do this, ignore the behaviour. Reassuring is the same as rewarding to a dog, and makes the problem worse.
My old Bloodhound hated storms, probably because she was kept outside before I adopted her. She would pace and drool and whine, but luckily not climb on my head. I'd just ignore her and eventually she would find herself a safe spot under a desk or behind the sofa until it was over.