The scarf is the 70cm Aloha design in dip dye for FW19. I don't think it has made it to stores just yet. Also, you might want to keep an eye on the seasonal scarf thread here instead.
Thank you Meta!
Availability will depend on what each store bought, especially given the high price point. That said, it will be returning in SS20, so if one isn't able to get one for FW19, there's still SS20.