How to keep a dog from barking at night?

My dog, that i've had from about 8 years is an absolute sweetheart. Except, lately she's picked up a barking habit in the middle of the night.. She has never been a barker, actually, she doesn't even respond to some things that is normal for other dogs to bark at. She has only picked up this habit within the last week or so.. she has a nightly routine.. Which is why this throws me off so much. Every single night..she lays on the couch with us while we watch the news, she follows me to the bathroom when I brush my teeth, she goes to the kitchen and gets food and a drink of water.. Then we let her outside to go to the bathroom. Then she races with me down the hall to climb in the kennel. Lol. That's pretty in depth. but, that's her routine. It never changes. So, I wonder why she's been doing this. It has stormed a couple of the nights. which she is extremely scared of, but, even when it isn't storming, she barks. So, is there anything i can put in her cage or outside of it, to ease this? Anything to calm her fear of storms? Please and Thank you! =)