Noises and Canals

2011-04-05 22:28:45.000 – Ryan Knapp,  Staff Meteorologist

With a sky this red, we knew something was coming.

The building we are in is pretty solid. Most of the outer walls are made of rebar and concrete that is about a foot thick or more. Walls with windows in them aren’t your everyday run of the mill windows either. Tower and basement windows are steel framed, double paned, and shatter resistant. Most of these windows aren’t very large and are a milky white from sun discoloration of the polymethyl methacrylate material (aka, Plexiglass) over the years. The windows in the weather room and the rotunda are larger dual-paned glass windows with a removable Plexiglass storm windows that we put up for winter months. Unlike the Plexiglass windows in other parts of the building, these are still clear since they are northern facing for the most part and are removed during the harsh summer light. Although they are large, they too are pretty solid. So between the walls and windows, most would think that we are in a nice, silent little protective cocoon. But this building is far from silent or solid during certain events.

When winds start cranking, the building takes on a low rumbling noise like a monster growling in the back of a cave and ready to pounce. As the winds increase, especially from a west to north direction (the orientation of the building) the sound is incomparable. I could say it is like a freight train but I don’t even think that does it justice. It just sounds angry. And when winds are cranking that high, the sound is equally matched by a rumble in the floors and walls. That’s right, winds over 100 mph actually shake our solid concrete building. If you put a cup of water on a desk in the weather room, it starts to ripple slightly like the scene in Jurassic Park when the T-Rex is coming on screen for the first time. It is a sight and a sound like none other.

Another common sound and movement in the building is when temperatures drop rapidly outside. When this occurs, the concrete and rebar start to constrict at different rates causing occasional “pops”. If the fluctuation in temperatures and expansion/constriction is large enough, these “pops” take on the noise of a shotgun and can create a quick rumble in the walls and floors around you. They are sudden and unexpected catching us off guard every time. When you first hear them, you almost want to dive for the floor but after a while they just make your jump like someone just said “Boo!” and startled you.

The third most common sound and movement in the building are around this time of year when we get warm and/or rainy weather. During winter, we get huge feathers of rime or thick coatings of glaze icing on our weather tower and surrounding structures. As the warm weather comes, the chunks of ice and rime start melting allowing them to start detaching themselves from the walls and structures they once clung to. As a result, they come crashing down on the deck or slam into the windows as they are flung around from the winds. The smaller pieces hitting the windows can be alarming but it is the large microwave and refrigerator sized chunks falling onto the deck that make me jump. This was the case last night.

Last night, we had a storm bring rain and temperatures up into the 40s. As a result, three large chunks of ice slammed down on the deck making three large thud noises and creating three little trembles all the way down into the weather room. Each time I heard one of them fall, all I was thinking was “Helmet!…Helmet!…Helmet!” Although, when I went out and inspected some of the chunks at the next observation, with my helmet on mind you, all I kept thinking was, if I were out here when these things were falling, my thin little plastic helmet would have helped a bit but I think I’d still be pretty banged up. But looking up to the tower, these three chunks looked to be all that I had to worry about since the rest of the tower was pretty much clear from the rapid melting the warm weather brought. This was a good thing because several times during the night I found myself on the deck trying to create little drainage ditches for the water that was creating little ponds in the areas we shovel around our tower exit; another problem that springs up this time of year when things start melting.

Although the deck was “puddling” up, it was nothing compared to the front entrance this morning. Jim (of NH State Parks) came in this morning asking for assistance in creating drainage for the water coming in at the front entrance. This isn’t a new issue since it runs in there any time it gets warm and rainy this time of year but the way it normally drains was plugged up. So, this resulted in about 4-6 inches of standing water that need to be drained off. So we created a few ditches in the snow and it slowly started to drain. And when all was said in done, it gave the front entrance a nice Venetian canals look to it this morning as we attempted to drain Upper Lake Manthisissuckee (as I nicknamed it).

Flash forward to tonight, and the summit has cycled back to winter conditions once again. Rime ice is forming on the structures, winds around 100 mph are making the building slightly rumble and growl, the “shotgunning” of the concrete has once again started back up and the canals that once directed water flow are filling back in with blowing snow. While it might sound like a wild 24 hours of weather to valley folks, this is just how we ring in spring up here; canal digging one day and crowbar swinging the next. It’s what keeps things interesting and what keeps me continually interested and loving what I do up here.

Ryan Knapp,  Staff Meteorologist