This plot shows the path N5TW experienced to VK3 during a geomagnetic disturbance (Kp = 5) on 26 September 2001.  Instead of the usual direct path of 243 degrees, signals were skewed to the Northwest.  During geomagnetic disturbances, it is quite common for signals to skew away from the auroral zone closest to the signal path...in this case skew was to the north.  Had the path been to Europe, signals would have skewed to the south.  The amount of angle skew is roughly proportional to the Kp index.  For Kp of 0-2, there is little noticeable skew but I've experienced up to 90 degrees when Kp was 8 (a path from Colorado to Sweden when signals were skewed to a 110 degree path from the direct 25 degree path).  The two auroral zones appear in light blue at each pole.