• Bryan Norcross

The western Gulf is percolating while a plume of dust heads toward Florida

A broad circulation has developed near the southern coast of Mexico in the extreme southwestern Gulf. Hostile upper-level winds and the proximity to land should limit any quick development of the system, but about midweek, there might be a window of opportunity for the system to organize, at least a bit.

At the current time, this system is part of the broad low-pressure area that often sits over or near Central America in June. In a few days, however, a weak disturbance currently moving into the Caribbean will add some spin and moisture. That combined with a more conducive upper-air pattern may well be enough to cause a tropical depression to form.

Toward the end of the week, the long-range computer forecast models indicate that the steering flow will change, allowing the system to move to the north.

The forecasts show a fairly hostile weather pattern over the Gulf mid to late week. Between the strong upper-air winds and dry Saharan air, the system’s opportunity to turn into much as it moves north appears limited at this point.

There is some question whether a pocket of upper-level winds that would allow the system to organize and intensify might move over the northern Gulf around the weekend, and whether that would coincide with the system’s arrival in that vicinity. In that case, there could be a short window of time for a depression or tropical storm to further develop. We’ll watch for that.

At the current time, the system is not expected to directly affect the Florida peninsula, although moisture surging north on the right side of the circulation will keep the humidity and the storm chances elevated.

The dry and dusty air that is forecast to affect the disturbance is part of a giant plume of Saharan dust that stretches across the Atlantic from its origins over Africa. The dust is forecast to surge west over the next several days, and on the current schedule would be noticeable in South Florida later in the week.

The effect on the weather over the peninsula depends on how much dust arrives. In any case, milky skies would be expected. If enough dust pushes in, it would limit thunderstorm development by drying out enough of the atmosphere to prohibit storms from forming.

Other than the western Gulf disturbance, there is nothing in the offing in the tropics.