Big winds explained

Scientist-blogger Grace Peng sent along this map of a jet stream slamming into Southern California, offering it as an explainer of what happened around the area today. Click it to biggify, or visit the California Regional Weather Server for the latest. Of course, it helps if, like Peng, you successfully defended a PhD thesis called "Simulations of Energy Transfer and Collision Dynamics in Small Molecules & in Cluster Ions." She's a believer, though, in low-tech weather analysis, as she blogged once at Bad Mom, Good Mom:

Because I don't have a wind gauge, I will have to use my eyes. Look at this tree across the street. It remained upright through the March 2006 storm only to list to the south this week after the storm. That's how the old meteorologists did it. They walked around with their eyes open and looked at the trees.