The Atlantic basin typically sharply increases in activity during the month of August, and the Atlantic remains active with three areas to watch, including Tropical Depression Emily. Emily is losing tropical characteristics and will likely be classified as a post-tropical remnant low at 11:00 p.m. EDT this evening. There are two other areas to watch in the Atlantic basin, a non-tropical area of low pressure in the Gulf of Mexico, and a tropical wave several hundred miles west-southwest of Cabo Verde. Neither is very likely to develop into a tropical cyclone at this time.

Emily losing tropical characteristics, likely to become a post-tropical remnant low in the next advisory

As of 5:00 p.m. EDT, Tropical Depression Emily was centered near 30.3°N 77.7°W, and was moving quickly northeast at 15 mph away from the United States. Emily currently consists of an elongated, exposed low-level center west of an area of deep convection. Although Emily is over 29°C (84.2°F) waters and wind shear is moderate, the cyclone is becoming embedded in a frontal trough. As a result, the Automated Tropical Cyclone Forecast system (ATCF) listed Emily as a post-tropical remnant low at 00:00 UTC. It is likely that Emily will be declared a post-tropical cyclone at the next advisory, and regeneration is unlikely due to cooling waters and increasing shear.

Two areas to watch in the Atlantic, but neither is likely to develop

There are two low pressure systems that the National Hurricane Center (NHC) is currently monitoring for possible tropical development over the Atlantic. The first one is a non-tropical area of low pressure located over the central Gulf of Mexico, about 250 miles south of Pensacola, Florida. This system has been producing some disorganized deep convection to the east of its center. It appears to have origins in the same frontal system that spawned Tropical Storm Emily. The NHC gives this system a 10 percent chance of development in both 48 hours and five days. None of the major global models (GFS, CMC, UKMET and ECMWF) predict any development of this system. Although wind shear is currently not very strong over this disturbance, it is expected that strong upper-level winds and dry air will not allow much, if any, development of this system. Regardless, it will need watching, considering the somewhat unexpected spin-up of Emily. This system has not yet been classified as an “Invest” by the NHC.

The second area the NHC is watching is a tropical wave located several hundred miles west-southwest of the Cabo Verde Islands. An area of low pressure has formed in association with this wave, which is currently producing disorganized showers and thunderstorms. The NHC currently gives this wave a 10 percent chance of development within 48 hours, and a 20 percent chance within five days. Some slight development cannot be ruled out for the next few days in a marginally favorable environment, but upper-level winds are expected to become unfavorable for development by this weekend. No reliable global models develop this system, and I simply would be very surprised if it developed. Much like the Gulf of Mexico area of interest, this system has not been classified as an “Invest” by the NHC.

While I do not expect the tropical wave currently on the NHC Tropical Weather Outlook to develop, there is another tropical wave expected to depart the coast of Africa tomorrow or Thursday. Several EPS and GEFS ensemble members have hinted at development of this wave near the Lesser Antilles, in addition to some earlier GFS and ECMWF operational runs. This wave will need to be watched more closely than the current one, and I think it will have a significant chance to develop. Now that we are in August, which is historically the second most active month of the Atlantic hurricane season behind September, these African tropical waves will need close watching.

I will be back for another post tomorrow, where I will provide an update on the East Pacific and West Pacific as well as the Atlantic disturbances.