Gulf and Atlantic Breezes

In the East, land and sea breezes are most pronounced in late spring and early summer, when land and water temperature differences are greatest, and they taper off toward the end of the warm season as temperature differences decrease. They are sufficiently strong during the spring and fall fire seasons to warrant consideration as important fire-weather elements in coastal areas.

Land- and sea-breeze circulations in the East are more often dominated by changes in the general wind pattern than they are in the West. Otherwise, the eastern land and sea breeze represents a more simple situation than the western because coastal topography is flat and uniform.

During the fire season in the East, general circulation patterns are such that on both the Gulf and Atlantic shores there are frequent periods of onshore or offshore winds strong enough to block or mask out land- and sea-breeze development. Onshore general winds almost always mask sea-breeze effects. During periods of gentle to moderate offshore winds, on the other hand, the sea breeze may develop and move inland. Against an opposing general wind, however, the sea breeze moves forward behind a small-scale cold front. This moves slowly, perhaps 3 or 4 miles an hour, and at times may oscillate back and forth with the varying force of the general wind. In addition to the rapid changes in wind speed and direction associated with a cold-front passage, a small area may thus be subjected to several of these passages over a considerable time. At this slow and intermittent pace, the sea breeze may have penetrated inland only a few miles by late afternoon.

Another feature of this type of sea breeze is that it is operating in an area of convergence. This is conducive to turbulent vertical motion in addition to the above-mentioned horizontal surface disturbances. This combination can create critical fire-weather situations, particularly in view of the fact that this type of sea breeze is prone to occur on high fire-danger days.

The reverse land breeze often becomes just part of the offshore general wind and thereby loses its identity.