When Geraldine Wharry calls from A&E and says that she knew she was going to be ill today, I‘m not surprised. It is her job, after all, to predict the future.

Clouds begin to gather as I stand out­side her home in North West London, waiting for her arrival. Eventually, I find myself sitting in her office. Rain spits against the window while two cats circle the room. Appearing from behind the door, Wharry, 37, has a delicate presence, with curly springs of dark blonde hair and owlish eyes that appear slightly bigger behind a large pair of glasses. Upon first glance, a certain professor of divination comes to mind.

Yet there are no crystal balls in her office, and not a soggy tea leaf in sight. Instead, a large Apple computer furnishes her desk. Most of the time, she tells me, its glass screen is the only thing she stares into when exploring the beyond.

As a trend forecaster, Wharry’s job is to provide brands with predictions of the cuts, textures, fabrics and colours we will all be buying in the future, sometimes up to two years in advance. With 14 years ex­perience, she is a senior voice within an industry that was recently valued at $32bn (£23bn).

Having worked full-time at one of the largest global forecasting agencies, WGSN, Wharry now operates freelance from her home, a stylish modern flat in Kensal Green. Sitting opposite me in her open plan office, the kitchen beside us, she attributes her illness to how busy the last two months have been. “If I don’t slow down,” she tells me, “I know I’m going to get sick.”

As it soon becomes apparent, Wharry’s gift of foresight is more a research-based skill than a mystical power. Seventy per cent of her work is done on her com­puter, and with most new clients finding her through social media, the first hour of each day is dedicated to maintaining her online presence. The remaining eight hours she then spends replying to emails, talking to clients, and “hunting and gath­ering” through the various blogs and visual archives of the Internet for inspira­tion.

Fashion feeds almost entirely on trends, and as the trillion-dollar plus industry grows, so does its appetite for knowing what they will be. However, Wharry describes what she does as being as much about archaeology as futurology. “I’m keeping track, collecting, dusting and archiving, but always keeping everything in mind,” she says; “and then I’m using certain elements to create an image of the future while always looking back as well. I love the push and pull between the past and the present. What you might find in a traditional African cloth you might find again in a GIF.”

There are two types of trend forecasts that Wharry makes. Short-term, or mi­cro trends, draw almost entirely from the catwalk, and are sold to the high street so that they can be quickly released into the mass market.

And then there are the long-term, mac­ro trend predictions. Taking into account much broader concerns, their aim is to second-guess how global events and shift­ing socials attitudes, as well as emerging visual trends, will affect a person’s spend­ing habits in two years time.

The names of macro trends, sleek and oxymoronic – Radical Neutrality, Eco Hedonism, Primal Futurism, Faux Real – sound as though they were made up by the evil twins of the people who coin political theories. But when she talks about them, you can tell that Wharry is completely on board, regardless of semantics. Excitedly she describes how Radical Neutrality was “all about making a big statement but still staying neutral,” as well as “disappearing but still making a statement”.

And when it comes to telling me about one of her proudest predictions, any pain her infection is causing her seems to dis­appear when she jumps up from the sofa, grabbing a large book from the shelf above our heads.

She flicks through its pages, which depict the Hopi tribe, and describes how she visited their reservation in 2011 while researching a macro trend called Idiomat­ic. They had always been a group she had been fascinated by, and after the trip she included their intricately crafted Kachina dolls in her report.

“No one I’ve ever spoken to knows about them” she tells me. “It’s not a culture people talk about.” Yet five months later, when inspecting one of the latest catwalks online, she saw her prediction sudden­ly appear in a brightly coloured Hermès scarf, covered in a Kachina doll pattern.

However, correctly predicting the fu­ture is one thing, but getting people to believe you is another. Wharry describes one Cassandra moment she had in 2009 while working for the label 7 For All Man­kind. From her research she started to spot the signs of a skimpy denim shorts trend emerging, in which anyone behind the wearer “gets a bit too much infor­mation”. Buyers and retailers, however, weren’t convinced that it was the future, and it never took off.

Of course, that was until this sum­mer, when a new phenomenon to rival the “sideboob”, called the “underbutt”, emerged, driven entirely by the booming popularity of such shorts among young women. “Beware the underbutt! Hotpants get even hotter as Miley Cyrus, Rihanna and Cara Delevingne sport shorts so tiny they reveal the buttock crease,” read a Dai­ly Mail headline in July. “We were just way too early with it,” Wharry explains with a slight grin. “Obviously, if we had predict­ed it for summer 2013, then we would have done really well.”