Lightning Tidbit

2014-08-07 19:18:27.000 – Brett Rossio,  Summit Intern

NULL

The day started with a quiet morning on the summit, but gave way to a busy start to the afternoon. A couple thunderstorms rolled through the summits, yielding some pea sized hail showers. Our shift leader, Mike Carmon posted some great pictures of the hail on our Facebook page! For meteorologists, this is what makes us jump out of our seats. Thunderstorms are truly a treat up here, but also very dangerous. Though the chances of getting struck by lightning are slim; standing on the summit completely exposed becomes exponentially more dangerous.

Imagine a large thunderstorm with very high cloud tops. Meteorologists like to call these clouds cumulus congestus or even cumulonimbus. Essentially when ice particles collide with very tiny water droplets in the cloud, electrons are being shaved off of the water and descend with these heavier ice particles. A strong positive charge develops at the top of the clouds with a strong negative charge at the base of the cloud. Eventually the electrons and protons are effectively separated between the bottom and top of the cloud respectively. In school we are always taught to never stand next to a tree in the vicinity of a thunderstorm. Not only is a positive charge building up in the top of the cloud, but also along the ground as well! The positive charge will surge to the highest point it may achieve which is where “cloud-to-ground” lightning occurs. When you are on the summit of Mount Washington, you are above tree-line and therefore become a high point for these protons. Electrons then descend toward the ground and reach for the highest point of contact with the protons to “balance” everything out. Once this is achieved, we see lightning. This is why being outside on the mountain can be extremely dangerous during a thunderstorm!

Brett Rossio,  Summit Intern