Grey tabby cat with blue collar

I lost my grey tabby cat, Kai, yesterday around 5:30pm. He's about 9 pounds, with white paws and a white chest, and he wears a bright blue collar with a tiny silver bell. I last saw him near the Boise Public Library on Capitol Boulevard by the State Capitol; he bolted when a dog barked and disappeared toward 8th Street. He’s usually friendly but a bit skittish with strangers, and this cat has sentimental value—he's kept me company through a rough year. There’s a small notch on his left ear and a faint white splotch on his right hip you might spot in photos. If you find him, please text me ASAP; I’m really worried and just want him home.