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Disturbance is near tropical storm strength in the Caribbean

Sept. 1 satellite image of the tropics.
Sept. 1 satellite image of the tropics. (CIRA/RAMMB)

We have reached the midpoint of the hurricane season on the calendar, but about 70% of the tropical energy that Mother Nature creates comes after September 1st. Category 3 or higher hurricanes are most likely to form in the Atlantic in September and the first half of October.

This year we are way ahead of normal, of course, in named storms. In fact, we’ve blown away the records with 13 so far, and possibly 14 today, if Tropical Storm Nana forms in the Caribbean. But, with 4 hurricanes, we’re not that much above the recent average of 3, and with one Category 4 in Laura, we’re about on pace.

Tropical Disturbance #1 is already generating winds over 40 mph in the vicinity of Jamaica, but it’s lacking a well-defined circulation at the surface of the ocean. By satellite, we can see a circulation in the mid-levels of the atmosphere, but the surface circulation is not evident. Hurricane Hunters will investigate the system this morning.

If they find a closed circulation, the system will likely jump to Tropical Storm Nana, since some tropical-storm force winds have already been measured.

In any case, the disturbance will spread gusty squalls over Jamaica and the Cayman Islands as it heads west. Countries around the west end of the Caribbean Sea are on alert, although the computer forecast models do not indicate that it will strengthen quickly.

Tropical Depression #15 is well offshore of the Southeast coast and moving away from the U.S. It is not expected to strengthen. The upper-level winds have become too hostile. It will dissipate in the North Atlantic in a few days.

Disturbance #2 over Africa is quite large. It’s forecast to move into the tropical Atlantic in the next couple of days and slowly develop into a tropical depression or tropical storm.  Steering currents are fairly weak over that part of the ocean right now, so nothing is going to happen quickly. It will be over the ocean for a number of days.

Long-range computer forecast models present a variety of solutions from turning it north into the open ocean to moving it west as a moisture surge. In any case, nothing threatening is expected to develop in the tropics this week, and there’s nothing obvious that would threaten us through Labor Day.


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