Boat alone on water in Alaska
A fishing boat traverses Cook Inlet near Homer, Alaska. Credit:

Many of the world’s older GPS devices had a Y2K moment on 6 April. Devices made more than 10 years ago had a finite amount of storage for their date accounting system, and that number maxed out on Saturday, 6 April.

Nineteen National Oceanic and Atmospheric Administration (NOAA) coastal and marine automated stations were not updated to mitigate the issue, and those stations are out of commission until workers can service them on location. The outage has the National Weather Service (NWS) office in Anchorage, Alaska, hurrying to fix their downed stations before bad weather comes in this week.

Old GPS devices have a counting system that tallies weeks from 0 to 1,024 using 10 bits of storage. After nearly 20 years of slowly approaching 1,024 weeks, GPS dates switched back to zero on 6 April, putting them out of synch with satellites.

The Department of Homeland Security (DHS) issued a notice in 2018 warning about the impending rollover event, which would affect a wide array of users, from utility companies to aircraft navigation systems. As the DHS wrote on their website, the rollover is a “standard design feature of GPS” and “not an unknown ‘bug.’”

In Alaska, five of the stations in and around Cook Inlet, which leads from the Gulf of Alaska to Anchorage, are down.

NWS’s National Data Buoy Center (NDBC) monitors a suite of equipment that lines the country’s coasts, and they identified the GPS issues 2 months before the rollover date, according to Stephen Cucullu, the supervisory general engineer for NDBC. The center managed to service 10 before the rollover but couldn’t reach the 19 remaining stations, which represent 42% of their total coastal and marine automated stations (C-MAN). NDBC engineers plan to service the stations “as soon as possible,” Cucullu told Eos, which may stretch on through the summer and fall.

“Huge Marine Responsibility” in Alaska

In Alaska, five of the stations in and around Cook Inlet, which leads from the Gulf of Alaska to Anchorage, are down.

Louise Fode, a warning coordination meteorologist at the NWS Anchorage office, told Eos that the station has “been fortunate that we’ve had good weather” but that a storm could be on the way later this week. The office plans to service two of the stations on Wednesday, 10 April, before the bad weather comes in.

The Cook Inlet stations cover locations that have “little to no other data” available, and the office uses the data to estimate conditions for vessels, particularly small fishing boats.

“In Alaska, we have a huge marine responsibility,” Fode told Eos. Traffic through the inlet includes fishing boats, cruise ships, and shipping containers on their way to Anchorage.

In the past when data have been unavailable, mariners have noticed and called the office, said Fode. “To them, knowing the wind and wave data is really valuable.”

Fode said that the office had “very little notice” about the outage. “We weren’t sure when it was going to happen,” she said.

Becki Heim, the NWS regional program manager at the Anchorage office, said that the NDBS is “doing everything” to respond to their needs quickly. “We’re really appreciative of the NDBC.”

“As with much of the weather industry, the more data the better.”

In Maine, two monitoring stations are currently down because of the issue and are scheduled for repair in August. NWS meteorologist Greg Cornwell from the forecasting office in Caribou, Maine, said that they “still have a pretty good network of data” but that they “don’t have a million buoys out there.”

When asked how the missing data could affect long-term records, Cornwell told Eos that it depended on the resolution needed. “If you’re looking at daily or hourly conditions, you’ll be missing a good chunk of data,” he said.

“As with much of the weather industry, the more data the better,” Cornwell noted.

NDBC anticipates the same issue arising in their weather buoys in July 2019, which Cucullu said the agency has been in the process of fixing “for a few years now.”

“We’re trying to expeditiously address the issue as soon as possible,” he told Eos. “We fully understand the importance of the observations to the users.”

—Jenessa Duncombe (@jrdscience), News Writing and Production Intern

10 April 2019: This article contains a correction to report the number of stations that have not been updated.


Duncombe, J. (2019), NOAA monitoring stations are off-line from a GPS Y2K moment, Eos, 100, Published on 09 April 2019.

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