A beach in Santa Monica shrouded in fog and low-lying clouds.
While visiting Santa Monica, CA, this past weekend I experienced rather chilly conditions along the coast; winds gradually picked up throughout the day and temperatures fell rather quickly despite temperatures further inland remaining steady. The locals refer to this feature as the “June Gloom”. It heavily reminded me of lake breezes back in Northern Illinois, which themselves behave in a very similar fashion to their sea counterparts. Moreover, these features are often associated with phenomena that include everything from lake-enhanced clouds to pneumonia fronts. In essence, these breezes derive from the same mesoscale feature which we will be exploring shortly.
Sea/Lake Breezes at their core are essentially the result of differences in surface temperatures between land and a given body of water; because water has a significantly higher heat capacity level than land, meaning that more heat is required to warm it, a sharp temperature gradient develops between their boundaries during the daytime. As air over land warms at a faster rate than the nearby body of water, it rises and cools, leaving behind a void over that is immediately filled in by cooler air over water that rushes in to make up for the change in pressure. This effect is essentially what defines any sea/lake breeze and results in mesoscale frontal boundaries that can travel all along a coastline and even inland under the right conditions.
Source: EA School Today
These features occur very frequently and at considerable intensities over places such as Florida, in which sea breeze-induced fronts tend to allow for enough lift to support convection, especially in the summertime. When warm, moist air rises ahead of cold air, it condenses and allows for the formation of short-lasting but fairly potent air mass thunderstorms. These storms can bring sudden downpours and intense lightning over concentrated areas along the frontal boundary and are a common concern for those who venture outside in the summer months.
Source: The Palm Beach Post
Other examples include the pneumonia front, a colloquial term for when a strong mesoscale cold-front moves ashore from Lake Michigan. As the cold, lake air makes its way inland, the air behind the front becomes stable and cools down significantly, resulting in dramatic drops in surface temperatures across Chicagoland.
Source: The Chicago Tribune
Likewise, the opposite effect can occur at night; because of water’s higher heat capacity when compared to that found over land, it tends to cool at a slower rate as well. This results in cold air rushing in from the cooler land to the void left behind over warmer waters as warm air rises. This leads to mesoscale warm fronts that then move over open water.
Source: EA School Today
Indeed, whether it’s the June Gloom of Southern California, the Pneumonia Fronts of Northern Illinois, or even summertime convection in Florida, these features all play a critical role in the mesoscale dynamics of the areas that they affect and are part of everyday life for those who live at their cross-hairs.
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©2019 Meteorologist Gerardo Diaz Jr.