Figure 3. Perturbation surface wind vectors and streamlines over Florida Bay for a typical easterly tradewind sea breeze regime, as simulated by the ARPS mesoscale numerical weather prediction model. At noon on August 25, 1975 a thunderstorm complex begins to develop just west of the intersection (vertex) between the west coast and east coast sea breeze fronts. Winds across the northern portion of FL Bay feed into an inverted, low-pressure trough (indicated by the heavy dashed line) associated with this storm. This trough induces northeasterly winds over the the western portion of FL Bay. Once it begins to rain, the downdrafts beneath the thunderstorm complex cause a divergent, high-pressure surge southward (indicated by the ridge axis line in the third panel). The outflow from this meso-high abruptly alters the wind direction in western FL Bay by 2:00 PM, as the cyclonic flow is replaced by anticyclonic flow. Combined with the inland-retreating west coast sea breeze front, it results in the formation of a weak secondary trough in the central portion of the bay. This trailing trough amplifies and begins to propagate westward by the end of the sequence, as the thunderstorm complex to the north dissipates.
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