It's not unusual for the tropics to be quiet in early July. It's also not abnormal for the sea breezes to kick off afternoon showers across the peninsula. This year, however, the Atlantic Basin is especially void of tropical activity, while at the same time those sea breezes are packing more of a punch. While the two might be somewhat related to our current El Niño cycle, the time of year and typical oscillation of the jet stream would be better explanations for this week's forecast.
Dust storms over west Africa are common this time of year, and right on cue we've seen several of them in recent weeks. The trade winds in the lower and middle regions of the atmosphere have allowed this dry air to spread over much of the Atlantic Basin, especially in regions where tropical waves are attempting to pass. And even if these tropical waves were able to survive this journey and produce appreciable thunderstorm activity, high amounts of wind shear would rip them apart anyway across the Caribbean or Gulf of Mexico. As a result of these two inhibiting factors, tropical depression or storm formation is not expected in the next five to seven days.
An upper-level disturbance has been steered deep into the Southeast U.S. by a large dip in the jet stream over the eastern half of the nation. Slightly cooler air aloft from this disturbance will work in tandem with tropical moisture over parts of central and south Florida to initiate widespread thunderstorm activity along both the Gulf and Atlantic sea breezes Monday and Tuesday afternoon. Heavy rain and gusty winds will accompany some of the stronger storms, with the highest coverage near I-95 north of I-4, then near and east of I-4 and I-75 in central and south Florida. By midweek, slightly drier air will move in from the southeast and start to limit the afternoon thunderstorm activity.
