When my dog (golden retriever/german shepherd mix) was a puppy, either me or my wife had to LITERALLY sleep in the crate with her during bad storms. Otherwise she would howl for hours on end. Nothing else would calm her down lol. Petting, holding, clothes with our scent. She'd stop for 2 seconds then go back to howling. Only sleeping next to one of us would lull her to sleep.
Now she's fine with storms but barks at nothing when she goes outside. Just a random "i'm here" bark then she goes about her business.