http://www.thespacereview.com/article/1553/1 (http://www.thespacereview.com/article/1553/1)
QuoteHowever, it is virtually guaranteed that a powerful geomagnetic storm, capable of knocking out a significant section of the US electrical grid, will occur within the next few decades. In fact, this may well happen even within next few years as we approach the next period of elevated solar activity, known as "solar maximum", which is forecast to peak in 2013.
QuoteThe possible extent of a power system collapse from a 4800 nT/min geomagnetic storm (centered at 50° geomagnetic latitude) is shown in Figure 2. Similar levels—10 times those experienced during the March 1989 storm—were reached during the great magnetic storm of May 14–15, 1921. A nuclear weapon would need to be a ~multi-megaton size to cause the equivalent E3 damage [15].
Figure 2:(http://www.thespacereview.com/archive/1553a.jpg)
Willing to bet its not gonna happen. Yousaf M. Butt may be an authoratative source, but so were the people that said we were gonna die from an asteroid a few years back.