General Store is a shop in Springfield.
Abe and Jasper were sitting outside of the shop when the air raid siren warning about an impacting comet blew, which according to them had been the first time it had been activated in the past three years.
Behind the laughter
The General Store's name and design referenced a type of shop, more specifically of the variety utilized during the 1940s. According to the director's commentary for Bart's Comet, the storefront, alongside an earlier gag involving two F-40 jets accidentally shooting themselves down due to mistaking Willie for an Iraqi Jet, was implemented as part of writer John Swartzwelder's sense of humor.