GeminiFocus April 2019 - Page 22

scope facility is rated to survive such winds with no distress to materials or structure. Even somewhat stronger winds of order 160 mph would not threaten the structure, as deformations would remain below the elas- tic limit. However, at 200 mph, significant failures would be expected. The recent ad- ditions to the support building, namely the many solar panels and base-facility opera- tion environmental sensors, were designed to the same wind speed standard as the rest of the building, and all survived the wind event intact and remained functional. This wasn't a particularly unusual storm sys- tem; it was a “Kona low," a low-pressure sys- tem which usually settles to the west of the islands (hence the name) but which this time was to the north. To put the wind speeds in perspective, an extreme winter storm on Mount Washington in New Hampshire, USA, in 1934, produced a wind gust of 231 mph, and in 1996 Cyclone Olivia produced a wind gust of 253 mph, setting a new world record. Figure 6. Top panel: The CFHT/ Gemini observed weather data from the Maunakea Weather Center site , at the time (16:43 HST) of the highest gust experienced there — 161 mph (top row, middle, red). Bottom panel: 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 10th at 16:40 HST (bottom frame). 20 GeminiFocus April 2019