Record Winds on Maunakea

This screenshot from the Maunakea Weather Center shows a wind speed of 96 knots (110 mph) recorded by the CFHT/Gemini weather tower on February 10 at 16:40 HST (bottom frame), just three minutes before the winds achieved a maximum speed of 161 mph (top table).

High winds plagued Hawai’i for several days starting on Friday, February 8th, and the Maunakea observatories experienced the brunt of the fury. The screenshot below shows the Maunakea Weather Center’s webpage, which demonstrates the power of the wind on February 10th between 16:33 until 16:43 Hawaiian Standard Time. The wind buffeted the CFHT/Gemini weather tower at a speed of 110 mph at 16:40 (bottom frame); three minutes later the winds peaked at 161 miles per hour (mph; top frame). Of the several weather towers on Maunakea, CFHT/Gemini’s provided the most consistent data; some towers were not operational, and others had enormous fluctuations over short periods of time. While it’s not the 191 mph winds that have been reported elsewhere*, 161 mph is still a record wind speed for Maunakea.

*Note: the 191 mph reading, which was reported widely on social media, was obtained with a suspect (highly fluctuating) instrument and is almost certainly erroneous.

Despite these conditions, and the fact that the Maunakea access road was closed for most of that week, the Gemini North telescope facility checked out fine. Ice was cleared on the dome, and all enclosure functions were tested and verified. The relatively new solar panels also weathered the storm and remained firmly attached to the roof. The only minor issue was the domestic water supply line freezing in the -12˚ Celsius temperature on the morning of Sunday the 10th. The water line to the restrooms was quickly repaired, but some additional repair work is required for the remaining lines, and for the deionized water unit.