In the past, if you asked meteorologists to name the toughest weather to forecast, the answer was almost universal: winter storms.
"It was a risky business to forecast substantial snow," said Greg Carbin, warning coordination meteorologist for the National Oceanic and Atmospheric Administration's Storm Prediction Center in Norman, Okla.
"We really struggled one day out: 'Is it going to be 3 inches, or is it going to be nothing?' " he said.
But improved technology, more training, and better understanding of atmospheric dynamics and developing storm patterns have helped meteorologists nail forecasts for one winter storm after another in recent weeks, regardless of whether they struck in the Great Plains, the Southeast or the Northeast:
* On Jan. 7, meteorologists warned that Atlanta could see 4 to 8 inches of snow and other parts of the Southeast could see substantial snow. The storm arrived two days later, and 5 to 7 inches of snow fell around the Atlanta area.
* On that same Friday, forecasters predicted 3 to 5 inches of snow for the Wichita area from a storm arriving Sunday afternoon and moving out a day later. Wichita recorded slightly more than 4 inches.
* As the storm that hammered the Southeast shifted north, forecasters cautioned that portions of New England could see more than 20 inches of snow. Cities in Massachusetts, Vermont, Connecticut and New York all saw more than 20 inches.
"It was just remarkable," said Mike Smith, president of WeatherData, a Wichita-based subsidiary of AccuWeather. "The days of being able to use meteorologists as whipping boys is coming to an end. The forecasts are getting very accurate."
Wichita residents may wonder whether winter forecasts have really improved after the storm system that moved through last week.
The weather service predicted Wichita would get 2 to 4 inches of snow and no ice. Instead, a light glaze of ice was followed by a mere dusting of snow.
So what happened?
A layer of warmer mid-level air developed in a 40-mile-wide swath that included Wichita and several other cities straddling the Kansas-Oklahoma line, weather officials said.
Precipitation fell as rain instead of snow, freezing on contact with the ground. The difference between rain and snow was perhaps 500 feet of cloud elevation, said Ken Cook a meteorologist with the weather service in Wichita.
"These little, subtle changes can make all the difference," Cook said. "It's a very big challenge.
"It's not a perfect science yet," he said. "There's still a lot of room for improvement."
Though Wichita didn't receive what was expected, Smith said, meteorologists nailed the forecasts for the rest of the state.
"I think we've seen really dramatic changes in winter weather forecasting skill in the last five to 10 years," Carbin said.
That skill has been sharpened by the availability of more than 20 different computer forecasting models — what Carbin calls "ensemble forecasts."
"I think the most revolutionary thing we've seen happen in meteorology, comparable to radar and satellites, is the use of ensemble forecasts," he said.
Those models are being fed with data meteorologists have not had access to until recently: sensors on commercial aircraft are collecting data from over the oceans that is relayed to the National Weather Service, Smith said.
Newer generations of weather satellites are providing humidity and temperature readings from near the surface of the Earth.
"The detail in some of those models is remarkable," he said.
That's valuable, he said, because it helps meteorologists more accurately gauge where different types of wintry precipitation may fall: snow, sleet or freezing rain.
The improved forecasts aren't just a product of better technology, weather officials said.
Joe Bastardi, AccuWeather's chief long-range meteorologist, credits "improved vigilance among people who want to excel."
"A lot are digging in and trying to 'hit' things because they are involved more," he wrote in an e-mail.
Meteorologists in the Wichita branch of the weather service had had "a pretty rigorous training plan for a number of years," Cook said, "and I think it's bearing fruit."
Carbin credits meteorologists with a better understanding of atmospheric dynamics, and Smith said forecasters are getting better at recognizing patterns in developing storms.
"It's one advance on top of another, to the point where you're noticing, 'This is not too bad. We're not really blowing these,' " Carbin said.
Winter storm forecasts figure to become even more accurate soon, weather officials said.
NOAA earlier this month dispatched a highly specialized research aircraft to collect atmospheric data over the northern Pacific Ocean to enhance forecasts of winter storms for all of North America.
NOAA is poised to install a dual Doppler radar in the Wichita branch of the weather service, once final touches on manuals and policies are completed.
Forecasters say the data made available by the new radar should improve recognition and understanding of winter storms.
"It really is amazing how far we have come in just a very few years," Smith said.