Otis is a big dog. Otis is a noble dog. Otis is in charge of the situation. Just ask him.
Otis is a Rhodesian Ridgeback. His size is the first thing a stranger notices. The first thing Otis notices about a stranger is a recognition of a new friend. He already knows you, and he counts on you to fulfill your part of the canine/human relationship equation.
Why, then, would a dog such as Otis, who clearly is in the driver's seat in the human/dog relationship world, crawl under a couch at the first sound of thunder? And, since he does and he is your foremost concern in life, what should you do about it? The following are ideas, suggestions and counsel gleaned from online sources. After scanning through them, I suggest you ask yourself, "What would Otis's mom have done?"
Medication
Here is a suggestion from one source – medication! Yes, it is true, there are dog doctors who will prescribe anxiety meds for your Fido. True, it is a proven palliative for people, so it makes sense that humans might extrapolate that result to think it might work the same for our animals. Stop and think, though – if it were not for us, would Mitzi really need medication?
Clothing
Another source encourages the purchase of an item of "dog clothing" which purports to provide physical comfort in the form of pressure that will counteract what we humans see as an irrational reaction to a mysterious phenomenon. Send them your money, they will cure little Chloe.
Another product available online treats the same phenomenon with a different causal factor. Their therapeutic item of dog wardrobe accomplishes its task by allegedly interrupting the electromagnetic field that is causing Dino's discomfiture.
Think like a dog
What is Otis really experiencing when he seeks shelter in a comforting spot when his world is in chaos? We should put ourselves in his canine paws instead of trying to understand his world from our limited human perspective. Dogs sense a drop in barometric pressure which portends an advancing weather system long before humans do. With that sensitivity, they detect changes in the electromagnetic field that we humans are oblivious to.
Dogs have a sense of hearing far more acute than our own. Remember Radar from the TV series M*A*S*H? His forebears must have been canine. Radar heard the choppers long before Hawkeye did. Of course, Hawkeye may have been otherwise distracted.
What else does Otis have over you, his mere human? Otis still has canine instinct that has not been blunted by technology, social complications, or self-medication. Listen to him. You are his person, his idol, his morning, noon, and night. He also recognizes that you are his bread and butter and the hand that feeds him.
When he is freaking out and you don't quite understand why, check the weather forecast. Chances are he is ahead of the local station's Storm Team and if you look further you will find the satellite image that shows what he already knows.
Batten down the hatches, comfort your best buddy as he unfailingly does for you, and watch the storm pass.
You will find this far more gratifying and effective than meds, counseling or clothing. So will he.