20:25 Mon Nov 23, 2020
Summer Days and Snow-vember Nights
Hello and windy greetings from the summit of Mount Washington!
My coworkers and I are currently in the middle of a 10-day long shift up on the Rock Pile, and it is shaping up to an exciting time. As I write this, Jay, Nate and I are finally about to experience our first snow event of the season. The summit has had a few snow events already, but so far, nearly all of the snow accumulation has happened while the three of us were off the summit, followed by a melt-out during our shift up. Finally, it seems to be our turn for snow! Currently, (11/22/20 at 10 PM EST) the summit is in the clouds with temperatures around 21°F, with winds out of the south at 49 mph. A low-pressure system is bringing a warm front through the region tonight along with plenty of moisture out of the south, which is currently responsible for the sparse snow showers passing through. Below is a spectacularly blurry photo of the snow coming in, illuminated by flashlight beam with our instrumentation tower in the background.
A few questions arose when it came to the forecast for tonight into tomorrow. How much snow will we receive? Will the warm front bring summit temperatures above freezing? Will winds gust over 100 mph tomorrow evening? Snowfall and high winds are always exciting, and these things can be difficult to forecast, especially when winter has not fully arrived yet. Only time will tell. So far this month it feels like we’ve jumped back and forth from one season to the next. The weather conditions this shift have been drastically different from our previous week on the summit. Two weeks ago, on Sunday, November 8, we broke the daily high temperature record, reaching up to 50°F in the afternoon. It was the first of five days in a row where our record daily high temperature was either broken or equaled. 50 degrees may seem chilly, but for us, it was like we time-travelled back to summer! To give you an idea of how warm that is for this time of year, the all-time November temperature record at Mount Washington is 52°F. If it were an average November day, we might have reached somewhere in the lower to mid-20s. It may not have been shorts-and-a-t-shirt kind of weather, but it was as close as we were going to get in early November. We had relatively light winds, sunny skies, and spectacular views from the summit for days in a row. Even on the non-record-breaking days, we enjoyed well-above-average temperatures throughout the entire shift. The snow and ice that had built up during the previous week had all but melted out, with just a few deep patches lingering. I really enjoyed finishing off my night shifts with a sunrise each morning. Below is one such sunrise – the photo was taken from inside the rotunda.
After heading down the summit in such nice conditions, the journey back up one week later was a perfect reminder of how rapidly the conditions can change. We left the summit in summer and came back up in winter. The summit had received 4-5 inches of snow over the course of several days during our week off, which is a relatively modest amount in and of itself. However, this amounted to deep snowdrifts on portions of the Auto Road that made it impossible to plow through by normal means. We discovered this over halfway up, requiring us to swap to the snowcat for the first time this season. Below is a wintry image taken from the Auto Road during the journey up last Wednesday. It may look mild, but it happened to be the coldest day of the season so far, with summit temperatures reaching a low of -5°F. It has been a while since I’ve felt that sort of cold, and it was a good reminder of what to expect in the next few months. Winter is certainly coming. As of right now it looks like temperatures will drop close to zero after this next cold front passes, with hurricane-force winds and wind chills of 30 below. The weather can be many things up at the summit of Mount Washington, but it is rarely boring.
David DeCou, Weather Observer