Windstorm in Colorado Disrupts US Official Time Standard
A recent windstorm in Colorado caused a ripple effect that disrupted the US official time standard by indirectly disconnecting more than a dozen atomic clocks from their system. These crucial atomic clocks, housed at the National Institute of Standards and Technology (NIST) in Boulder, Colorado, were impacted by the hurricane-force winds that wreaked havoc on trees and electricity infrastructure in the state.
The severe weather conditions prompted the state’s largest energy company to implement safety shutdowns, leading to a backup generator failure at NIST and a subsequent slowdown of NIST coordinated universal time (UTC(NIST)) by 4.8 microseconds.
While 4.8 microseconds may seem minuscule in human terms, it can have significant consequences for critical infrastructure, telecommunications, GPS signals, and more, as explained by NIST supervisory research physicist Jeff Sherman in an interview with NPR.
Despite the power outage, the atomic clocks at NIST continued ticking thanks to their battery backup systems. However, the connection between some clocks and NIST’s measurement and distribution systems was disrupted during the incident.
At the NIST laboratory, more than 20 atomic clocks, including hydrogen masers and cesium beams, are used in rotation to determine UTC(NIST). These clocks are continuously monitored by primary and alternate multi-channel measurement systems to detect even the smallest frequency changes.
Data from the measurement systems is processed by computer algorithms to determine the official time in the US, which plays a crucial role in contributing to the world’s time standards.
Following the restoration of power at the NIST facility, the temporal blip caused by the windstorm has been corrected by the dedicated crew.


