Cumulo-What?!

So today was quite an interesting day for weather. This morning the roads were wet from the rain yesterday and overnight, but was a beautifully sunny morning. I brought my rain jacket to campus with me just in case. After the crappy string of 3 classes in a row, I found myself with two hours to blow (I could have been productive, but the beautiful day wasn't letting me stay inside) so I went downtown to do some "window shopping" at the gear shop downtown. You know.. dreaming of goose down coats, headlamps, ski pants.. stuff like that. I didn't take my rain jacket along, convinced that a rain storm couldn't fly in that quickly. Afterwards I decided to roll on down College Ave some more and found the farmer's market very enticing. I stopped by and got some goodies, and saw a dark cloud approaching in the distance. I should have ran at that point, but didn't. Instead I went into another PSU gear store to browse around. When I came back out and headed back to Walker, I knew I was in trouble. The dark clouds encompassed the sky and and the wind began to pick up. Then the rain came. And came. And came... so to say the least I got rained on.. a lot. Whoops. I was taking refuge over roofs but didn't feel like sticking out the entire time for the storm. I felt pretty silly since my rain jacket was sitting in my office. After I got back to Walker, soaked, the squall line gave a couple of streaks of lightning and left us, leaving a trail of these little guys behind...
What are those you ask? Cumulonimbus mammatus clouds.. only the coolest clouds ever!! Weather nerds get excited about them.. and honestly, the whole 6th floor WAS pretty excited about them. After they lingered for awhile, the sky completely cleared up and the awesome fall weather ensued.