#### Some of the low-rank spatial signatures were sensitive in opposite ways to Hurricane Irene (August 28, 2011).
Hurricane Irene increased the traffic flow on signature 1 and 2 (top left and top middle), but decreased the traffic flow on other signatures (e.g., Signature 3, which is top right). The blue line is the signature weight for the day of interest, the green lines are the signature weights for the remaining days of the year, and the red line is the average of the signature weights for the year. Work by Yu Wu.