Hello! I am Stephen Gill, an oceanographer with NOAA. I’ve been studying sea level and tides and currents for the past 40 years. My office within NOAA is responsible for providing near real-time tides, currents, and Great Lakes water level information. These data are quality controlled to compile long-term archived data sets that can be used to produce tide and tidal current predictions among other important products such as tidal datums and sea level trends. As you may know, tides vary with the changes in the alignments of the Earth-Moon-Sun system. In general, the closer the alignment of the three bodies, the greater the tides are. One special alignment that occurs a few times each year is the perigean spring tide and we are currently experiencing one of these events right now. September 28 is especially noteworthy because Perigee and the Full Moon occur within a few hours of each other on this day, resulting in high tides being among the highest and lowest for 2015 in many coastal locations. I’ll be here from 1:00 p.m. ET (10 am PT, 5 pm UTC) to 3:00 p.m. ET to answer your questions on perigean spring tides. For more information about me, my bio can be found online at http://oceanservice.noaa.gov/news/sep15/reddit.html