If you were at a New Jersey beach over the holiday weekend, you certainly noticed an eerie fog overhead while blue skies dominated to the west.
At times, temperatures dropped when the low clouds won out against the sun and spiked as sunshine temporarily burned away the fog.
What caused it?
A combination of summer-like air temperatures, cool ocean waters, and higher dewpoints due to tropical moisture streaming in from the south, forecasters say.
Fog develops when warmer air moves over the cooler waters, according to the National Weather Service. Adding in tropical moisture, dewpoints rise, resulting in more water vapor in the atmosphere.
That’s a recipe for heavy fog near the beaches but not inland, where higher temperatures as compared to the beaches (cooled from an onshore breeze) inhibited the development of low clouds, allowing for abundant sunshine.
It’s fairly typical for this time of year.
In late May 2012, NewsWorks’ then Down the Shore blogger Jen A. Miller wrote about foggy South Jersey beaches.