Yesterday a cold front plowed across New England, smashing against the mountains and chasing storm clouds into the sea. A wedge of cold air brutally shoved aside a warm, moist air mass, clearing a path for sunshine and less humid weather. In the afternoon, a sudden burst of convective energy triggered yet another thunderstorm. Cumulus congestus clouds ballooned skyward, flattening against the roof of the troposphere, 7 miles high. The jet stream—a high-altitude river of wind racing at over 200 mph.—sheared off the tops of thunderheads and hurled ice crystal clouds hundreds of miles downwind.
The atmosphere is a violent place. A "front" is the boundary between warm and cold air; it's a word that Norwegian meteorologists borrowed from military terminology after World War I. Air masses fight for territory on the Earth's surface, like armies at war, and that's what reminded scientists in the 1920s of the recently concluded European nightmare.
Six quadrillion tons of nitrogen, oxygen, carbon dioxide, water vapor, and other trace gasses are constantly jostling each other in our sky. Sometimes it feels like the worst of their battles occur right here on Mount Washington. Hence the mountain's nickname, "Home of the World's Worst Weather." Whether the mountain really deserves that designation is debatable, but it's true that hurricane-force gusts (74 mph. or greater) hammer the peak more than 105 days a year. Yesterday we fell just short of hurricane status, topping out with a gust of 65 at the precise moment that the front rolled into Coos County.
On weather maps, a cold front looks like a long blue curve with jagged triangular spikes stabbing into the east. The spikes symbolize a sharp spear of cold wind and rain. Yesterday's front is now sliding out across the Atlantic, bothering nobody but the fishes (and the fishermen). In its wake, the wind atop Mount Washington shifts to the northwest. Cooler, drier air trickles down out of Canada. That brings us relief from the oppressive heat of the last week. By "oppressive" I mean temperatures in the 50s, peaking at 63 degrees Fahrenheit on Monday. It rarely gets warmer here. The mountain's all-time hottest mercury reading is only 72 degrees. In late June, it's usually in the 40s. That's one of the perks of this job: natural air conditioning.
It's hard to believe that only three weeks ago we were still cranking up the thermostat and shoveling snow. Springtime didn't arrive this year until June 8. I still remember the day. I was outside taking some measurements and slinging a psychrometer, a device that measures temperature, dew point, and relative humidity. Suddenly—thump!—a block of ice fell off the tower and hit me on the top of my head. An ice storm had struck the mountain the previous night, but as soon as the sun came out, all the ice started falling off the buildings with loud, brittle crashes. Well, not quite all. In some shadowy corner there must have been one piece left. It broke loose and landed right on my noggin. Just my luck.
I was facing east and never saw it coming. Based on the size of the pieces it broke into after whacking me on the head, I estimate it was about the size of a football. Warm blood started streaming down my forehead into my eyes. I didn't panic. Hurrying back inside, I grabbed some paper towels and held them to my head. The rest of the crew looked at me in pure horror; my face was stained red. However, since I could still repeat numbers and measurements coherently and showed no sign of dropping dead on the spot, they finally determined that it must look worse than it was. Since there was still a weather report to code and file, an intern transcribed the numbers for me while I cleaned myself off and applied pressure to the wound. It's strange to realize how the courses of our lives can be determined by split-second actions. Had I walked across that exact spot one second sooner (or later), none of this would have happened—and I wouldn't still be puzzling over the best way to wash bloodstains from Gore-Tex gloves.
The weather has warmed up since that day. In fact, it's warmed up so much—nearly breaking the record high temperatures for several days—that talk at the observatory has turned from winter to global warming. The Earth's average temperature is currently 59 degrees Fahrenheit. But ice-core samples reveal that the climate has been both much warmer and much colder in the past. The pendulum swings both ways. Ocean levels fluctuate over time.
We need to remember that heat is energy, and energy, at least in a meteorological sense, is violence. Turning up the global thermostat a notch will give the atmosphere a little extra oomph. Thunderstorms, tornadoes, and hurricanes will pack more of a punch. Everyone's heard the dire predictions of heat waves and rising sea levels. The worst scenarios describe a surging ocean swallowing each tiny Caribbean island like a modern-day Atlantis.
The observatory staff jokes about Mount Washington becoming "beachfront property," thanks to global warming. "Are these mountains below sea level?" we once were asked.
"Not yet!" we replied, laughing. Still, there's no doubt that the sea level could rise. Any future melting of the polar ice caps, combined with the thermal expansion of water, will mean you'll need to bring snorkeling gear the next time you visit downtown Miami. If the entire Antarctic ice cap someday melts, in our nation's capitol only the tip of the Washington Monument will protrude above the waves. Who knows? If so, Kevin Costner's movie Waterworld might actually enjoy a revival. But it will be hard to find a theater with dry seats.