NULL

2006-05-30 04:03:50.000 – Tim Markle,  Chief Observer

Being night observer during the summer certainly comes with its share of perks. For one, it is great to be able to leisurely stroll around the deck looking at the stars and city lights on those clear, calm nights. Second, the dark of night doesn’t really last all the long up here. The twilight of dusk lingers until just after 10pm while the twilight of dawn arrives around 3am. It is a quiet time free of worry of having to venture outside, alone, on those brutally cold and long winter nights.

One downside to the summer is the thick, wet fog. The warmer air can hold more water, and hence the fog can be extremely dense. Changing the precipitation can at night and turning back to the building can sometimes reveal nothing but a wall of black. The fog is not always dense, and such was the case last night. A thin and shallow fog encompassed the summit just after midnight, and lingered for about two hours. This made for some tough observations, as the fog was thin enough to see city lights and other cloud layers. Hence, I could not code fog but had to report it as a cloud layer. The trick was that I really had no frame of reference in which to judge the prevailing visibility or the other cloud heights. This is usually when experience plays into the mix. However, a new variable played into the tricky observations: haze.

The haze around the summit was thick enough to reduce visibility to around ten miles just before sunrise. Although the fog had since departed, I still had to throw my hands into the air when I went outside. I simply had no idea what I was looking at! The clouds and haze blended together and I could see no lights other than those from the Mount Washington Hotel. I took my best guess using what was happening from the previous hours, but that was tough because I was basing everything on what I had seen through the thin fog.

Now that the sun is up and the visibility has improved I can see that the my reported cloud heights seem right, but I missed all of the clouds to the west of the summit. Oh, well! Not everything is easy on a quiet summer night!

Tim Markle,  Chief Observer