MIAMI – Arthur is heading out to sea. First, the circulation will likely transition to a pretty strong wintertime-type storm, and then it will fade out in the open Atlantic. The tropical storm churned up the ocean pretty good, so dangerous beach conditions continue along the East Coast north of South Florida.
Recall it was wintertime-like weather systems that spawned the system that became Arthur – an old cold front and a couple of upper-air disturbances. The mixture of winter-like systems and tropical weather is what normally kicks off early season storms, and is why late May and June are, on average, rainy periods in South Florida. When cooler northern systems invade the tropics, the contrasting air masses roil the atmosphere in a variety of ways.
The extremely heavy rain in South Florida is being caused by one of those northern-type low-pressure systems parking itself over the Southeast U.S. It’s forecast to move out, however, and by late week, we’ll return to more typical pre-rainy-season weather with a nice breeze off the Atlantic.
Official Rainy Season in South Florida began on May 15, but that date is just an average. In terms of the weather pattern, the Rainy Season begins when cold fronts and dry air incursions from the north, and the humid, tropical air takes control.
In spite of the extremely heavy rain the last few days, the transition hasn’t quite happened yet. At least one more round of less-humid air is coming, so enjoy it late this week. The tropical air will be lurking just to the south.