Wisconsin forecasters more accurate with improved technology - Minneapolis Star Tribune

SULLIVAN, Wis. — On a recent morning, a bomb cyclone plundered its way up the East Coast.

The nasty nor'easter not only created heavy snow and high winds, it also locked a frigid cold snap squarely over Wisconsin.

In eastern Jefferson County, meteorologists at the National Weather Service office in Sullivan finally predicted some relief to a prolonged run of wintry misery in the state.

Every day, 24 hours a day, workers at the rural location monitor changing weather information to update forecasts for 20 southern Wisconsin counties, including Rock and Walworth.

Sometimes, they are wrong.

But the people who predict wind, rain and snow are more accurate today than ever before thanks to improved technology.

"The advancements have been tremendous," said meteorologist Steve Davis, who has worked for the National Weather Service for 30 years.

In part, he attributes the increase in forecasting accuracy to computer modeling at the National Weather Service center.

The former Milton man, who now lives in Palmyra, said the changes have been incremental in recent decades.

"When I started, we issued a two-day forecast with a three- to five-day general overview," Davis told the Janesville Gazette . "Now, we issue seven-day forecasts that challenge the two-day forecast accuracy from 20 years ago."

Forecasts still fall apart for any number of reasons, "but not as often as they used to thanks to the advancements of computer modeling," Davis said.

A powerful mainframe computer system in the National Weather Service office is fed with information about what is happening in the atmosphere in real time, including radar readings of the locations of rain and snow and real-time satellite observations of clouds.

Three "American" weather models predict what is happening in the next 24 hours, the next three days and the next two weeks.

"Different weather services throughout the world have developed their own models," meteorologist Tim Halbach said. "That is why you will hear references to the European model."

The 24-hour forecast is typically reliable in terms of temperatures and precipitation.

"Beyond three days, it is less reliable," Halbach said. "We always tell people to check the latest forecast."

He called forecasters "their own hardest critics if things don't go the way they predicted."

"If we are wrong, we review the forecast to make it better next time," he said.

More than a year ago, the National Weather Service launched a new weather satellite that improves the visibility of smaller things and relays information more quickly.

"Instead of imagery every 15 minutes, we are getting it every five minutes and, at times, every 30 seconds," Davis said. "This allows us to see rapid trends in thunderstorm development."

As a result, forecasters can see where storms are starting more quickly and can issue more-timely warnings.

"I strongly believe our focus on early heads-up to these events, coupled with timely warnings, saves numerous lives every year," Davis said.

Both he and Halbach said their main goal is to keep people safe.

They work with decision makers in school districts, including Janesville, first responders, departments of public works and emergency management at both the local and state levels.

Instead of just issuing a forecast and hoping users understand it; they interpret the information so officials can make critical decisions, such as whether to close schools.

Davis called the new role for forecasters rewarding.

"The direct interaction we have with our users and knowing we are having a big impact on their decisions is very motivating," he said.

Halbach realizes firsthand why it is so important to issue tornado and severe-weather warnings.

He grew up in Fond du Lac and witnessed the devastating Oakfield Tornado of July 1996.

"I watched it from the driveway of my parents' house," he said.

In addition to satellites, the station depends on information from Doppler radar, which Davis called "unmatched in its ability to track weather moving through the area."

In addition to telling them how intense precipitation might be, radar also gives them wind information by tracking the movement of rain and snow particles.

"This allows us to see wind circulations within a thunderstorm that pinpoints the genesis of tornadoes or strong straight-line winds," Davis said.

Without getting too complicated, the radar sends out both horizontally and vertically polarized electromagnetic waves.

By comparing the results of the two signals, forecasters get an idea if the precipitation is hail, rain, snow or even birds or bugs.

The radar reaches all the way to Green Bay in the north to northern Illinois in the south.

Forecasters also depend on people to provide them with important data.

"We get a lot of information from storm spotters and chasers," Halbach said. "We have a network of people who report what's in their rain gauges. People think it's all about technology. But there are limitations to technology, and we still depend on people to provide information."

In addition to the general forecast, meteorologists also issue aviation, marine and fire forecasts, and they have a large hydrology program that tracks and forecasts river stages for many locations across southern Wisconsin.

Davis called each work day different.

"I have a new puzzle to solve every time I walk in the door," he said. "Some days are quiet, and some days are controlled chaos."

In recent years, forecasters have become more engaged with social media, which gives people "an avenue to be brutally honest and, at times, insulting," Davis said.

Still, "we have far more positive interactions with the public than ever before," he added.

He believes one of humankind's greatest achievements is predicting weather.

"We are predicting the future state of an incredibly complex and chaotic system," Davis said. "Our forecasts aren't always perfect, but they are very reliable. Even our harshest critics look at the weather forecast every day."

An AP Member Exchange shared by the Janesville Gazette.

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