The 24-year-old last night completed his temporary switch to Valley Parade from Championship club Watford.
Parkinson has moved for the Scot after Kyel Reid suffered a setback in his recovery from a groin injury that means the left winger may be out until Christmas.
With Bradford having a scarcity of naturally left footed players, the club’s manager thought it wise to bolster his squad with Forsyth.
He said: “Kyel’s situation means we don’t have too many left footed players. Zavon Hines and Garry Thompson have filled in and done very well.
“But in terms of balance, I felt we needed to bring someone extra in.”
Forsyth started his career with Dundee and moved south to Vicarage Road in the summer of 2011.
He made 20 appearances last season in the Championship under Sean Dyche but has found opportunities to be much more limited since Gianfranco Zola took charge in the summer.
As a result, his only involvement has been in the Capital One Cup with one of his two appearances this term having come ironically against Bradford in the second round.
Today’s visit of Cheltenham Town comes at the end of a week in which City had a rare blank Tuesday.
It was the club’s first midweek without a game in a month and Parkinson admits the break was timely for a squad that has already played 16 games and who are due to play on each of the next three Tuesdays.
The Bradford chief said: “The break has proved useful. We gave all those who played against York last Saturday a day off on Monday and then everyone was back in together the following day.
“It is amazing how just one day can make everyone keen to get back into training. The break has also allowed us to treat a couple of injuries that we’ve been trying to keep quiet.
“Andrew Davies was one of those we’d been nursing through but he is fine after a week without a game. The same goes for Luke Oliver, who had been struggling.”
City are without a win in four games but the manner of their second half display in last week’s 1-1 draw at home to York City smacked of a team in decent form.
Parkinson, who says Rory McArdle reported back fit from international duty with Northern Ireland this week, added: “We hadn’t been at our best in the first half but came to life after the break. We need to start against Cheltenham how we ended the game against York.”