Home prices have run so hot for so long along the northern Front Range, it is hard to imagine them reversing course in a significant way.

But Location Inc., a geographic research and real estate data firm, warns that years of rapid appreciation will shift into a stretch of falling prices starting in late 2019. More specifically, the forecast says, median home prices will fall by more than 20 percent during the following few years, due in large part to a growing gap in wages and home prices.

“At some point, the fundamentals are, ‘Can people afford to buy it, and what are their alternatives if they can’t afford to buy?’ ” said Andrew Schiller, CEO of the Connecticut firm. “Prepare for a reversal.”

This month, the company rolled out a new forecasting product called Scout Vision that crunches more than 200 variables on a national, metro and local level — all the way down to “micro” neighborhoods — to predict the direction of home prices across the entire country three and five years out.

The northern Front Range, which includes Boulder, Denver, Greeley and Fort Collins, would see continued home-price gains this year and into next before the market tops out in the third quarter of 2019 and starts moving lower.

Scout Vision predicts median home prices across the region in the first quarter of 2022 will be 21 percent lower than in the third quarter of 2019. The forecast doesn’t go beyond 2022, but the steepness of the drop points to continued declines beyond then.

The company’s five-year forecast, starting in the first quarter of 2017, predicts a 9.3 percent decline in the region’s median home prices.

In that model, metro areas across the northern Front Range would move from having some of the strongest home price gains in the country to some of the weakest. Key to the decline would be the ratio of household income to median home prices. In northern Colorado, prices are 4.5 times higher than income, compared with 3.49 times nationally.

The company also tested its analysis on the most recent housing downturn, in 2006-11, correctly predicting that Los Angeles and Miami home prices would be hard hit and that Dallas and Houston would escape declines. The model also closely tracked with home prices from 2000 to 2016 in northern Colorado.

The forecast’s next five years reveal a patchwork of falling and rising prices across the northern Front Range.

Scout Vision is calling for median home prices in metro Denver to drop by 11 percent by 2022, with wide variations based on neighborhood.

Homes in the 4700 block of Argonne Street, part of Denver’s Green Valley Ranch neighborhood, are projected to lose nearly a third of their value, repeating a pattern of steeper-than-normal losses seen during the housing downturn, according to Location Inc.

The 4200 block of Wyandot Street, in Denver’s Sunnyside neighborhood, is forecast to see home prices rise 15.6 percent five years from now as its proximity to downtown and walkability help it weather the downturn.

Boulder, whose home prices have historically been fairly resilient, would be the northern Colorado metro area most at risk of price declines, facing a drop of 17 percent from this year through 2022. In Boulder, neighborhood home values would fall by anywhere from roughly a tenth to a third from current levels.

Fort Collins would be looking at a 5.5 percent drop in median home prices five years out, while Greeley would fare the best of the four metros, with flat prices five years from now.

Anthony Rael, former head of the market trends committee at the Denver Metro Association of Realtors and an Arvada real estate agent, said he wouldn’t be surprised by Location Inc.’s five-year forecast.

Rael contends that the ongoing shortage of homes and continued migration to metro Denver will support double-digit price gains through this year and into early 2018 but that the upward trend can’t last forever.

“Affordability is major concern, so the one thing that will upset the apple cart most immediately are interest rates that start hovering in the high fives,” Rael said. “Once the brakes are applied and buyer demand begins to drop off, that will naturally pull prices back down.”

In contrast to Location Inc.’s starker prediction, Rael’s preference would be a scenario of moderating increases leading into a long-lasting, flat market sometimes described as the “high plateau.”

Schiller emphasizes that Scout Vision isn’t predicting that the northern Front Range faces the kind of residential real estate stagnation seen in many Midwestern cities. But neither is it going to defy gravity like San Francisco or Manhattan, where people keep buying seemingly no matter how high prices rise.

“If demand is pushing home prices up but wages aren’t increasing, it gets to be tenuous. It will come crashing back,” he said.

Especially at risk would be buyers late to the game. Anyone buying around the forecast for the peak in median prices, in 2019, would have a deep hole to dig out of.

“We always knew that location, location, location was important. What came out of this research is that it isn’t just location, but it is also timing,” Schiller said. “If you miss the timing, you have to wait for the next swell.”