A wave of Saharan dust from northern Africa was moving over South Florida Saturday and heading northwest.

As mid-June draws near, there is a “hush” over the Atlantic basin, in part due to the presence of the Saharan Air Layer or SAL.

The first large plume of Saharan dust made the 4,000+ mile journey across the Atlantic to South Florida, turning the sky a gray and dull.

There are three disturbances in the Atlantic plus Hurricane Enrique in the Pacific to watch today.

The large tropical disturbance that moved off the coast of Africa this week is slowly progressing across the eastern tropical Atlantic.

Claudette was officially downgraded to a tropical depression because the highest sustained winds dropped below 40 mph.

The surge of dust is forecast to arrive at the southern Florida peninsula about the middle of next week. Right now, it appears the dust layer will be light enough to allow big thunderstorms to form, but we’ll see.

A mass of tropical moisture associated with a tropical disturbance over the Bahamas will push through South Florida late today and tomorrow. Embedded in that flow are minor disturbances of increased moisture, drier patches, and eventually another round of Saharan Dust. This one also has a slight chance of organizing somewhat before it reaches the islands or the coast of South America. On the current schedule, the next round of Saharan Dust will reach Florida over the weekend or early next week. The combination of the dust and the strength of the Atlantic high should keep the tropical Atlantic quiet through this week, at least.

The dominant feature from Africa across the tropical Atlantic is Saharan Dust. A denser part of the plume has moved over South Florida, which is making the skies quite milky and should limit the number of thunderstorms that develop. When there is a lot of dust over us, there are fewer thunderstorms and its extra hot and humid. This general change in the flow of air will bring in tropical moisture, which we should notice beginning Friday. But the dust and developing strong Atlantic high-pressure system are forecast to keep them well south and unable to develop.

The remnants of Tropical Storm Fay are speeding out of the Northeast and into Canada today. The flow around the bottom side of that large low-pressure system put a light west wind across South Florida. In and around the Bahamas, the Straits of Florida south of the Keys, and the near-shore waters off the southwest coast, the water is three to six degrees above normal. Take away the ocean breeze effect, and we really heat up, as we’ve seen this summer. Long-range computer forecast models bring in a decent ocean breeze with the disturbance as part of a general shift in the dominant wind direction over South Florida.

An area of low-pressure is trying to consolidate over the warm ocean waters east of the Carolinas. The main threat appears to be from the heavy tropical rain, which may cause local flooding. The circulation is still broad, and the gusty winds and heavy rain are on the east side the offshore side of the system. If the center hugs the Jersey Shore and the system consolidates, heavy tropical rain and gusty wind will affect the whole region. Because we dont know exactly what the worst will be yet, residents in the path should stay informed.

Of interest today is a non-tropical low-pressure system spinning over the South Carolina coast. The center of this circulation is forecast to cover the North Carolina coast, and from there move north, over or just offshore of the Mid-Atlantic and the Northeast coastline. In the winter, we would call this a noreaster a coastal storm that produces northeast winds at the coast. (TropicalTidbits.com)The odd thing this year is that the ocean water is unusually warm just off the shoreline from North Carolina north to New England. There have been tropical storms that move up the coast in July, but not that originate as a broad non-tropical low over land.

Some things have changed over the last week, but the dust remains. A belt of Saharan Dust continues to create hostile atmospheric conditions from Africa across the tropical Atlantic, the Caribbean, and into the Gulf of Mexico. As a result, no development is expected in that zone through much or all of next week. In short order, is should be absorbed by a large low-pressure system moving across the North Atlantic. There is a light layer of Saharan Dust in the atmosphere over South Florida.

A look at tropical ocean temperature. (National Hurricane Center/NOAA)Otherwise across the tropics, satellite measurements of the Atlantic water temperature show that the tropical waters are running warmer than average. There is a pretty direct correlation between the water temperature in the tropical Atlantic and the number of named storms and hurricanes in a season. The tropical ocean is not wildly above average, but even this amount of extra warmth makes a difference. Most often, a warm ocean by this time of the summer stays warm into hurricane season.

The upper-level low-pressure system that is forecast over the Southeast over the weekend will finally change the incessantly super-hot weather pattern over South Florida a bit. South Floridas record heatYesterday, the weather pattern evolved into a classic one for South Florida heat. With strong June sun, few clouds and a light breeze blowing over the city on the way to the Miami airport thermometer, the temperature soared to 98, tying the highest ever recorded there. The NOAA reanalysis of the weather pattern on the record-setting day in 1942 shows a wind flow similar to what we had yesterday and expect to have today and tomorrow. In any case, were going to be under an extremely hot weather pattern for at least the next couple of days.

A tropical disturbance is approaching the southern Caribbean islands, but it has run into hostile upper-level winds and Saharan Dust and its falling apart. The disturbance represents a moist gap between two clouds of dry Saharan Dust. The Saharan Dust is no doubt playing a part. In addition, the Saharan Dust acts like a blanket, trapping heat near the earth at night. With this current pattern, wed expect hot weather, but not crazy hot.

The massive cloud of Saharan Dust that that blanketed the Caribbean early this week has mostly moved past South Florida and into the Gulf of Mexico. This type of minor impact from Saharan Dust is a normal occurrence in July. The good side of the Saharan Dust spreading across the tropical Atlantic is that it keeps tropical development under control. When one of these passes by, it can be a factor in enhancing or squashing tropical development potential. On the other hand, the Saharan Dust will continue to be a negative factor for development.