'Astronomical' Cliff Erosion Forces Chatham Weather Balloon Launching Station To Close

CHATHAM (CBS) - March 31 was an end of an era in Chatham. The National Weather Service's Upper Air Observation Station, located on Morris Island, launched its final weather balloon after 60 years of continuous service. It's somewhat ironic that after tracking weather for so long, this observation site is about to fall victim to it.

The site for the balloon launches is on the top of a 40-foot cliff with sand and ocean below. Andy Nash, meteorologist-in-charge of National Weather Service Boston, said that over the last six months, the erosion in that area has been "astronomical." The bluff is losing 1 to 2 feet per week on average, with some storms grabbing 6 feet of sand.

While rising sea levels are certainly part of the issue, a storm in 2019 exposed a weakness by tearing a cut in the sandbar offshore. That's exposed the bluff to the full force of the ocean and waves.

Rather than allow the building to fall into the ocean, it will be demolished in the next few weeks. The National Weather Service is exploring options to relocate the launch site to another coastal location, but that could be a year or two down the road.

Every day across the country, weather balloons are launched at 92 different locations. These aren't your normal birthday balloons. At the ground, they are four feet in diameter. As they ascend to the upper atmosphere, they grow to be the size of a house before bursting. Attached to the balloons is an instrument package called a radiosonde. The radiosonde sends back data like temperature, dewpoint, pressure and wind speed at different heights of the atmosphere.

Nash said a weather balloon "gives us a profile, a snapshot of what the atmosphere is doing at that time. Weather is three dimensional. It's not just at the ground, but it's above our head."

These profiles of the atmosphere can be viewed in real time but also go into computer models to help paint a clearer picture of the future.

Nash said all the energy for the project has gone into a demolition effort. Once that wraps up, the process for identifying a new location for launches will begin.