17:52 Mon May 16, 2016
How Windy is Windy?
If you’ve ever spent time on the summit with me, I call all wind from 40-70 miles per hour “a bit breezy”. With winds pushing the century mark, and gusts up to 109 mph, I think I will upgrade that to “Blustery.” But how windy is windy, really?
It’s really impossible to imagine the winds on the summit without experiencing them firsthand. The Sherman Adams building has 3 foot thick concrete walls and 3 layers of bullet-resistant glass windows. Even with this protection, the constant, dull roar of the wind is ever-present in the Observatory’s Weather Room. Heading up to the tower to deice every hour is an adventure; the enclosed parapet-like tower roars like the sound of a jet engine as a plane is taking off, and exiting the top door of the parapet is like opening up the window of that ascending jet.
The top of the tower is surrounded by a solid, chest-high railing that blocks most of the wind. In the center of the top of the tower is a 5-foot-tall, concrete cylinder designed to raise the wind instruments above the turbulent influence of the tower railings. In low and moderate winds, we climb up a vertical ladder on the side of this concrete block and duck under a 3-foot-wide red, metal ring attaching various vertical instrument posts. Carefully using a delicate deicing instrument (crowbar), we chip up to half a foot off of the instrument posts on top of the tower. Our critical instruments are heated, but the rime ice building off of these instruments can quickly envelop heated instruments (or at the very least, disrupt air flow).
After wind surpasses around 80 mph, we avoid climbing up the last section of exposed ladder to the instruments, instead opting to deice as much as we can from down below, using a crowbar to send vibrations through the metal posts that attach to our instruments. Next stop is down to the deck to do the real science.
Our official observation point is deck-level. Luckily, during fog observations, we don’t have to use the Sling Psychrometer which takes about 2-10 minutes to give us a reading. Down on the deck, it is easy to underestimate the power of the wind, as our westerly winds put the deck door in the lee of the tower. This is a blessing and a curse; the suction in the lee of the tower is incredible, and opening the deck door in strong winds requires a mighty shoulder-push to overcome the strength of this suction.
Once out on the deck, we must (carefully) check for precipitation. High winds typically (but not always) occur as a low pressure departs and high pressure builds in. In the winter, low pressure systems often bring us snowfall, quickly turning into blowing snow as winds ramp up. Discerning whether there is snowfall or blowing snow (or both) is one of our hourly tasks, and the easiest way to do this is to take a felt-covered board and hold it in the wind. This makes it easy to determine what form of ice is flying through the air (the ice that you can so easily feel through many layers of clothing).
After that, the observer heads back down to the Weather Room (directly underneath the deck) to submit the observation. While we do record and disseminate our observations digitally, filling out paper-and-pencil form is still an hourly routine. I’ve worked to improve my handwriting ever since starting with the Observatory, but all of that work goes down the drain after a windy observation. With adrenaline coursing through my veins, my hands shake almost uncontrollably, making my writing look like that of a 5-year-old.
Wind on the summit is an experience that you can’t just describe to understand. It makes you fully appreciate that air is in fact a fluid and not empty space. It is really impossible to safely face down hundred-mile-per-hour winds almost anywhere else; you’d either be risking your life trying to hike into them (I was exhausted after several minutes of playing in the wind) or risking your life in a hurricane, where flying debris and shrapnel poses a huge threat. Whether safely surfing the blustery wind or relaxing on the couch in our living quarters, I am very thankful for my experience here on the summit!
Mike Dorfman, Weather Observer/IT Specialist