Bad to nice

2011-08-18 00:43:30.000 – Ryan Knapp,  Weather Observer/Meteorologist

Tower and sunset today.

The weather was surprisingly nice today, which is always a bit odd at a place known for “The World’s Worst Weather”. When I started out from my home in the valley, skies were overcast with light drizzle and temperatures were a bit cool. As soon as I reached the base of the summit in Pinkham Notch for shift change, the skies opened up and perfectly blue skies surrounded the summit. Winds and temperatures on the summit were right where models had us in the 40s with Relative Humidity (RH) of 80-90% with winds 25-40 mph but within an hour, winds dropped to around zero, RH dropped to less than 50% and temperatures soared into the 50s. And then this pattern held through most of the day until close to sunset. With meetings occurring, I had no idea of the sudden change until we were downstairs for lunch and I noticed the abrupt change on our weather display. It was a pattern typical of instrument failure so I quickly started to ask the observer on duty if the electrical equipment matched what he observed and he said it had. So why the abrupt change?

Well, it is a bit of a head scratcher. I didn’t do today’s forecast or look at any models prior to coming up and having been in meetings or asleep for most of the day, I didn’t really get to observe the weather in person. But the nice thing about weather data is we can go back and look at the data after the event and draw some conclusions. So, after examining the data and remembering what skies looked like during sunset when my shift started, I have two theories. One, the high crested in a lot quicker than models picked up on and then lasted longer than expected. And/or theory two, a strong inversion was present which tends to coincide with the auto road vertical profile as well as all other instrumentation data we have up here in addition to a clear cut line on the horizon separating the haze below and cleaner air above. So a combination of the two weather events broke the weather pattern for the day and made for an ideal day on the summit making for a great day for all the tourists that made their way to the top by foot, car, stage van, or cog. I wish I could say that the ideal weather pattern was expected to hold but I know better and unfortunately, stormy weather is ahead. So make sure to check the higher summits forecast by us or NWS before heading out in the coming days to pack and plan a safe hike on and around the summits of New Hampshire.

Ryan Knapp,  Weather Observer/Meteorologist