Mount Washington Observatory: Measuring the “World’s Worst Weather”

A winter sunrise reveals the summit sign atop Mount Washington. The Mount Washington Observatory tower, topped by the parapet that holds weather instruments, is visible in the background. Rime ice laces all: sign, tower, and trail-marking cairn. Photos by Ryan Knapp/MWOBS unless labeled otherwise.

Rising to an elevation of 6,288 feet, Mount Washington caps New Hampshire’s Presidential Range and is the highest peak in the Northeast. On a clear summer day, hordes of visitors flock to the summit – via hiking trails, a paved auto road, and even a train – lured by panoramic views, cooler air, and a chance to snap a photo by the summit sign. But the weather can turn brutal with a mere shift of the wind. Winter is a particularly unforgiving season here, high above tree line. Known as the “Home of the World’s Worst Weather,” the mountain has also been home to the Mount Washington Observatory (MWOBS) for the past 90 years.

In every season, during every hour of every day, a “weather observer” from the Observatory leaves the Jack Middleton Weather Room in Mount Washington State Park’s Sherman Adams building at the summit to measure temperature and wind speed. Observers also note cloud type and cover and how snow has drifted and piled on the observation deck. This hourly excursion is no small feat. It regularly involves exposure to hurricane-force winds and subzero temperatures, and observers must clear snow and rime ice from data-collecting instruments.

Back inside, the staff inputs data and studies weather radars and forecast models to create the daily Higher Summits Forecasts. The observatory, a nonprofit, member-supported organization, also provides data to the National Weather Service, offers educational programs and workshops, and collaborates with scientific and educational organizations to conduct weather- and climate-based research – from the powerful influence that mountains have on weather to the effects of climate change on high-altitude environments.

MWOBS Weather Observer and meterologist Ryan Knapp (right) points out various snowdrifts on the observation deck to intern Will Gabbert. Observers note how the drifts change during the course of the day, indicating wind speeds and direction. Photo by Sam Robinson/MWOBS.

Meteorologist and MWOBS Director of Weather Operations Jay Broccolo uses a sling psychrometer to measure ambient air temperature, which helps weather observers calculate dew point and relative humidity (the amount of water vapor in the air). “This manual weather observation process has been happening the same way, every hour, since 1932,” said Charlie Buterbaugh, director of communications. A sling psychrometer consists of two thermometers – a dry-bulb thermometer and a wet-bulb thermometer – attached to a spinning handle. Weather observers must swing the instrument in circles to take a reading.

The sling psychrometer shows a temperature of negative 14.8 degrees Fahrenheit at the summit during this mid-December reading.

Jay Broccolo checks out the view from the weather room. While this “view” is typical at the summit of the Northeast’s highest peak, MWOBS meteorologists brave the elements every hour to collect weather data. Despite the challenges of the job, weather observers often inject a bit of humor into social media posts, as was done with this photo.

A summit intern shovels access to the instrument tower near sunset. The metal A-frame structure provides protection from large chunks of ice blowing or falling from the tower and other structures. During significant icing on the summit, ice may grow at a rate of 1 foot per hour, and chunks may be as large as a car engine. Weather observers also wear protective gear including helmets and goggles.

The Hays Chart in the Mount Washington Observatory shows summit winds steadily increasing on a January morning.

MWOBS Weather Observer Sam Robinson climbs the tower parapet at the summit to inspect instruments during a storm. The parapet provides a place for observers to brace themselves against wind and driving precipitation as they take readings from the various instruments there, including two pitot-static tube anemometers, which measure airflow speed.

Snowdrifts are a regular occurrence on the summit.

Jackie Bellefontaine, a weather observer and education specialist for MWOBS, uses a precipitation board. Weather observers use this board to collect and record which type of frozen precipitation is falling and blowing across the summit.

Jay Broccolo peeks out the window of the snowcat that carries observers to and from their weeklong shifts atop Mount Washington. During the summer, observers can drive the Mount Washington Auto Road, a paved 7.6-mile route from base to summit, in about 30 minutes. In winter, however, the snowcat must often clear drifts along the route, and the same trip can take as long as 3½ hours to complete.

The MWOBS resident feline, Nimbus Kitty, keeps watch in the weather room – and makes regular appearances on social media. Cats have prowled the observatory’s space since its inception in 1932. “We’ve always had cats on the summit,” said Charlie Buterbaugh. “They’ve played the role of protecting food from mice, but they’re also companions.”

A sunset view from the summit of Mount Washington, looking toward the Franconia Ridge, hidden in the clouds, with the ski slopes of Bretton Woods visible on the right. The tower at the center is a communications tower.

February moonlight highlights the summit sign on Mount Washington.