The winter ocean doing strange things

Hourly water temperature, parsed by year, from the NDBC 46041 buoy off of Washington's coast

I was going through some wave metrics from the Cape Elizabeth buoy and noted this interesting water temperature pattern, and though I would throw up a quick blog about it.  The figure above shows each year's temperature data by day of the year.  The bold red line is this year, 2019.  Water temperature plunged about 2C in a matter of days...a fairly rare thing for the winter when temps tend to be fairly uniform.  

I've highlighted two years in the record when something similar seems to have happened this time of year...in 2014 (the sort of reddish bolded line) and in 2018 (the purplish bold line).

Monthly average water temperature from the Cape Elizabeth buoy (blue line), and the anamoly from the 1999-2008 average (red line).

Its also worth noting that up to that point the ocean was pretty warm.  The figure above shows the anamoly from the monthly average, and we are still in this phase of warm winter ocean water that kicked off in 2015.  In fact at Cape Elizabeth there have been only two warmer Januaries, in 2003 and 2016.

Hourly water temperature, parsed by year, from the Port Angeles tide gauge

 Just out of curiosity I also downloaded the water temp data from the Port Angeles tide gauge...shorter record, same idea.  Same pattern here.  Perhaps its not a coincidence that at about the time that this water temperature plunge started it got really cold here in Port Angeles.