The online weather category—dominated now by the behemoth Weather.com—is about to get a well-funded and technologically-advanced new competitor.

Weather Central, a company that provides technology and weather graphics to TV stations representing 47% of the U.S. market, is launching a consumer web site, MyWeather.com, promising real-time accuracy on an area as small as 12 square blocks.

The consumer site is part of a remake of the company under new ownership. E.L. Rothschild LLC, the investment company owned by Chairman Sir Evelyn de Rothschild and CEO Lynn Forester de Rothschild, took a controlling 70% stake in the company in January. The remaining 30% is held by the company's management, including CEO Terry Kelly, who will continue to run the company.

Weather information is ubiquitous on the web and on various apps on mobile platforms. It also has several very well-distributed incumbents including the Weather Channel, whose Weather.com reached nearly 39 million unique visitors in April, according to comScore, as well as Weather Bug and Weather Underground, which also provide weather information to TV stations and have large consumer web sites.

Weather Central is betting its technology, a data center in Madison, WI that crunches global weather data from numerous sources, will provide greater accuracy that consumers will notice. "You can imagine that weather can be a bit of a commodity, but what excites us about this is that they have—the 160 people in the company—developed algorithms and software that can forecast weather down to one kilometer basis," said Ms. Forester de Rothschild, in an interview.

But Weather Central isn't counting on a consumer site alone (nor various mobile and tablet apps) for growth or to pay all the bills. The company is already serving a critical mass of TV stations, but wants to provide weather data on any number of web portals, apps and search engines. "I think the ad-only model for a business is a very tough model," Ms. Forester de Rothchild said.

Weather Central provided the data for NBC's weather network Weather Plus , which was shuttered soon after the company acquired a stake in Weather Channel, which was acquired for $3.5 billion in 2008 by a consortium including NBC Universal, Bain Capital and Blackstone Group.

The company, founded in 1974, expands E.L. Rothschild's media holdings, which includes the UK-based Economist Group. Asked if she's planning more media investments, Ms. Forester de Rothschild said no, adding that she's very focused on the weather. "Some see a connection between this and the Economist--150 years old--best-in-breed for the intellectually curious. Myweather will do the same thing--be the best and the most innovative weather service for the intellectually curious."