If conditions are right, smaller thunderstorms may also form along the sea breeze. The most important thing to recall is that warm air rises and cold air sinks. Without this phenomena, fronts would not form. Land always heats up faster than water. In this SkyWise temperature image, you can see Florida in darker reds and oranges than the water surrounding it. This is the perfect condition needed to create that nice, inland front while you lay on the beach.
However, it is not a unique condition to the Sunshine State. It can happen in any coastal area, as well as along large bodies of fresh water.
In many areas, cities further inland may be sweltering. Hop in a vehicle and head to the beach and the temperatures will be much more pleasant! Here is a classic radar signature of a sea breeze moving inland. You can see how it is parallel to the coast and once it gets going, it actually moves quite far. During the day, the land surface heats up faster than the water surface. Therefore, the air above the land is warmer than the air above the ocean.
Now, recall that warmer air is lighter than cooler air. As a result, warm air rises. Therefore, the warmer air over the land surface is rising.
This boundary, called a sea breeze front, acts in the same manner as the cold front we typically experience. The skies also clear after the sea breeze front pass by.
Another change that takes place with the passage of the sea breeze front is an increase in humidity. Over land, air forced up by the sea breeze front will begin to cool. This cooling means the density increases again forming a small area of high pressure 4. Typically, this occurs from 3, to 5, feet 1, to 1, meters in elevation. At this level the air pressure and density, being greater than the same elevation over the water, causes air to flow back over water 5.
Once over water again, the air cools, increases in density and sinks toward the earth's surface 6. This enhances high pressure near the ocean's surface 7 and the whole process repeats as land flowing air pushes the sea breeze front further inland. While the sea breeze is generally associated with the ocean, they can occur along the shore of any large body of water such as the Great Lakes. These changes occur in a relatively small scale weather-wise.
However, if there are larger scale atmospheric conditions also affecting the weather, then the sea breeze and sea breeze front can have a much larger impact on the type and intensity of weather one observes. Just like along cold fronts, if weather conditions are right, thunderstorms often develop along sea breeze fronts.
The location and number of thunderstorms will vary depending on the overall weather pattern over the region. For example, in Florida the amount of sunshine and prevailing surface wind over the state has a large impact on sea breeze thunderstorms. Light west wind mph keeps the sea breeze front confined to the eastern coast but also makes for more widespread thunderstorms along the boundary.
Stronger west winds can prevent the sea breeze front from moving onshore or forming at all, so no thunderstorms will occur. With prevailing east winds, they actually help push the sea breeze front and thunderstorms as much as half way across the peninsula.
On smaller peninsulas, such as at the northern tip of New Zealand, sea breezes from opposite coasts may collide.
0コメント