Storer, 19, started his career with Birmingham before moving across the Midlands to Wolverhampton Wanderers and then earning his first senior contract at Stevenage.
He moved back to Birmingham in 2016 before last appearing on loan for Yeovil Town.
The 6`1” striker will be in the squad to face Braintree Town this weekend and he has been given permission to play in cup competitions by his parent club.
“Jack is a very talented forward and we are very grateful to new Birmingham City boss Steve Cotterill and Richard Beale the senior professional development coach for making this happen” said Gloucester manager Tim Harris.
“Recently we have had Jack watched in the Birmingham City under-23’s and enquired about his availability, though I have known him from his days at Stevenage
“We’ve simply not scored enough goals and in Jack we know he’s the type of striker we have been looking for, he will look to test the goalkeepers which is something we have not done enough of”.