A memorable storm

2011-02-18 17:20:55.000 – Brian Clark,  Observer and Meteorologist

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First of all, our microwave radio link from our tower on the summit to our Weather Discovery Center in North Conway was down from about 9 p.m. last night, to about 4 p.m. this afternoon. During that time period, temperatures hovered right around the freezing mark, sometimes just above and sometimes just below. This creates a thin layer of water between the ice covering the microwave dish and the dish itself, which in turn refracts the beam enough to prevent it from connecting to the valley. Luckily, now that the cold front has passed, temperatures have begun to fall, the layer of water has frozen again, and our link is back up!

Anyways, now on to what I wanted to write about. Since coming up on Wednesday, I have been working the overnight shift, which has been Ryan’s territory for the last 5 years. Ryan is taking a few days of vacation, and will be back up (if the weather allows) tomorrow. In the mean time, I always enjoy the chance to work nights; it’s a nice change of pace for me, and only something I have had the opportunity to do only a handful of times over the last 3.5 years.

During the wee hours of the morning on Thursday, while I was writing the summits outlook for the day, forecasting models were showing highs reaching the mid 30’s. This time of year, seeing high temperatures like that automatically makes me think there is the potential for breaking a daily record high. So, i took a look at our almanac and saw that it the record high for February 17 is 34 degrees, set in 2006. Seeing that sparked some memories for me.

On February 17, 2006, I was a relatively new intern on the mountain. The storm that arrived that day was a warm one, meaning that the center of the low cut up through the Great Lakes, putting us on the warm, eastern side of the storm. This caused temperatures during the mid morning hours to surge to that record high of 34 degrees. By early afternoon, the cold front had passed, temperatures began a free fall, and the wind increased to sustained speeds well over 100 mph. In fact, between 3 and 4 p.m. that day, the average wind speed was 115 mph and the peak gust was 137 mph (also the peak for the day). Temperatures continued to drop all the way into the evening on the 18th, eventually bottoming out at 30 below zero, which set a new record low for that day. Winds also continued to remain high, with another 100+ mph wind gust on the 18th (112 mph). So in the end, this storm set a record high one day, then a record low the next, which involved an incredible temperature swing of 64 degrees in about 18 hours. It produced two 100+ mph wind gusts, as well as wind chills as low as 80-90 below zero.

Five years later, this storm is still the one I talk about when I get the frequent question of ‘what is the most extreme storm you have experienced in your time on the mountain?’. Although I have seen a few storms storms produce more snow and precipitation, or colder temperatures, and some very close wind speeds, this particular event had the most extreme combination of elements I have ever experienced in my time calling Mount Washington home.

Brian Clark,  Observer and Meteorologist