Thursday, January 22, 2015

Sea Fog and Lowered "King Tides"

Local weather enthusiast and the maestro of Skunk Bay Weather Greg Johnson sent me some impressive imagery and video of sea fog off of Point No Point on the Kitsap Peninsula around 8 AM yesterday (January 21st).  Click on the image or link to view it.


Why such a nice display of this shallow fog?

We start with relatively warm water......here is the sea surface temperature at the Orca buoy at Hansville, only a few miles away from the Point No Point lighthouse (I got this on the wonderful Nanoos website provided by the University of Washington).  The water was around 49F.

It turns out, that the air temperatures were relatively cold that morning,dropping into the mid 30s, as shown by the observations at Greg's Johnson's Skunk Bay Weather Site, which is quite close to Point No Point:


Same story at Port Townsend


So relatively cold air was passing over water, water about 12-15F warmer.  Moisture from the warm water was able to saturate the cold air (cold air can "hold" less water vapor than warm air) producing the shallow fog.   This kind of fog is also called "steam fog".

 The other big water story are the "King Tides" that will be occurring the next few days. Here is a plot of the predicted and observed tides.  They will be particularly high Friday and Saturday.  


But here is an interesting observation--the observed tides (red) are less than predicted (blue).  Why?

The reason is that atmospheric pressure is running higher than normal and high pressure pushes the water down, reducing the water level.  So perhaps we should call them "Queen Tides" this year.  A fascinating aspect of King Tide periods is that they give you a feeling what the typical tides will be in roughly 150 years from now due to global warming---if we let it happen









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