The 25-year-old former Scunthorpe forward has been in fine form for high-flying Notts in League One.
Forte, who scored a hat-trick against league leaders Charlton on Saturday, has struggled to secure regular first-team football in Nigel Adkins' side since joining last year.
"I've still got two years left on a contract at Southampton and it's a massive club," he told Sky Sports.
"What an incentive for me to get back there for Premier League football.
"But I can see County also going up if the lads keep playing like this. They are fantastic."