Sandy produces near record wave heights on Lake Michigan - DC Breaking Local News Weather Sports FOX 5 WTTG

Even though Sandy continues to weaken, it has produced the second highest wave ever measured at the south mid lake buoy at 21.7'.

Records for the south mid lake buoy date back to 1981 and is only deployed seasonally from early Spring to late Fall. It's certainly possible that larger waves could have occurred on Lake Michigan during the winter months when the buoy was not deployed. So these values represent the highest values on record.

What makes this storm even more remarkable is the duration of extremely high waves. At the south buoy every hourly observation from 5AM this morning through 3:00PM had wave heights 18 feet or greater.

Going back through the 31 years of archived data from the mid lake south buoy, there had been only 15 hourly observations with wave heights of 18 feet or greater. Prior to today, the record for the most number of consecutive hourly observations with wave heights 18 feet or higher was back during the November 10th-11th 1989 storm when there were 7 consecutive hourly observations with waves 18 feet or greater.

Below is a list of the top five highest waves at the mid lake south buoy.

STORM DATE PEAK WAVE HEIGHT

1) SEPT 30 2011 22.9 FT

2) OCT 30 2012* 21.7 FT*

3) NOV 11 1998 20.3 FT

4) OCT 20 2011 19.2 FT

5) SEPT 23 1989 18.4 FT

In addition, wind gusts have been close to 70 mph near the lakefront. Here's a list from the NWS here in Chicago.