Another hurricane threat to southern US

Developing cyclone to bring flooding to Central America before striking the eastern Gulf Coast.

Nicaragua can expect a widespread 300 to 500mm, with as much as 750mm in some locations [Jorge Torres/EPA-EFA]

A developing tropical depression has formed in the southwestern Caribbean, and it has the potential to cause considerable disruption in both Central America and the US states of Florida and Alabama.

Tropical Depression 16 (TD16), to give it its full name, was 120km to the southeast of Puerto Cabezas, at 06:00 GMT. It was heading northwest at 9 kilometres per hour. This track, and is expected to continue over the next 36 hours. This will result in TD16 posing a threat to Honduras and Mexico’s Yucatan Peninsula, before strengthening as it heads across the Gulf of Mexico.

Winds within the system are relatively light, with sustained winds of 55 km/h. The main threat from TD16 will come from the warm, moist air within its circulation, which is generating huge amounts of rain.

Rainfall totals of 125 to 250mm, with a localized total of 500mm, are expected over Panama and Costa Rica.

Nicaragua can expect a widespread 300 to 500mm, with as much as 750mm in some locations – 750mm is the equivalent of three months worth of rain. Nicaragua’s northern neighbour, Honduras can expect 50 to 125mm.

Mexico’s Yucatan Peninsula will receive a direct hit from the cyclone around 00:00 GMT on Saturday. At this stage, the system will be a tropical storm with sustained winds increasing to 100km/h.

After that, the tropical storm will quickly intensify into a hurricane. It will take advantage of a raft of favourable factors, including sea surface temperatures of more than 30C; low wind shear (a change of wind speed and direction with height); and a moist atmosphere.

Most current forecasts take what will be known as Hurricane Nate, on a trajectory which will take it across the Gulf of Mexico. Landfall is expected at 00:00 GMT on Saturday on the eastern part of the eastern part of the Louisiana coastline. Mississippi and Alabama may also feel the effects of the hurricane before it begins to weaken.

Although forecasts only intensify Nate into a Category 1 hurricane on the five-point Saffir-Simpson scale, it is worth pointing out that previous hurricanes such as Irma, Maria and Harvey have intensified more rapidly and to a greater extent than was initially thought. Could the exceptionally warm waters of the Gulf of Mexico cause Nate to follow suit? Only time will tell.

Source: Al Jazeera