Well, of course, you feel sorry for the pup and you've probably (I'm guessing) have been saying things like, "poooooooor baby, it's OK....A-w-w-w-w." And you're probably worried and anxious. Well, if that's the case, you may be inadvertantly reinforcing her fearful feelings and behavior. Try getting your own self into the frame of mind (ahead of time) that.....woooo hooo, this is just going to be swell. Snow is so much fun, the flakes coming down, throwing snow balls for pup, taking walks where she can bound and leap around in the fun stuff. Same thing with the rain. Take a little mini walk and take along her favorite toy and some treats and just act like you always do when you take a walk....don't fuss over her or let on that you're concerned with her fear. Play her favorite game with her and just act like it's no big deal. If it was pouring hard that time and it was loud, it indeed may have frightened her. Try associating the rain now with everything that is good and fun. And don't act worried yourself. Be confident. Reinforce her with a treat and attention when she shows even a couple of seconds of fearlessness or interest in the toy or something else. When she's afraid, don't fuss over her, just walk along and see how she does. When in the house, when it's raining, if the noise makes her nervous, try distracting her with her favorite game and some treats.....pair those times with good things. She should get past this. This is what I've always done with thunder storms and none of my dogs have had that common fear. It thunders, the best toys come out from hiding (reserved for special times) and some tasty tid bits and jolly ole' me. LOL.