AFTERNOON TROPICS: THURSDAY, OCT 17, 2019

THE NATIONAL HURRICANE CENTER HAS DESIGNATED THE TROPICAL DISTURBANCE IN THE GULF POTENTIAL TROPICAL CYCLONE SIXTEEN. IT’S A BIT OF A TECHNICALITY THAT ALLOWS THEM TO ISSUE WATCHES AND WARNINGS FOR THE NORTHERN AND NORTHEASTERN GULF COAST. IT IS THE LIKELY THAT THE SYSTEM WILL DEVELOP INTO A STORM NAMED NESTOR LATER TODAY OR TONIGHT.

The DEVELOPING STORM in the extreme southwestern Gulf of Mexico is producing gusty thunderstorms and it close to developing an organized circulation. The upper-level winds are reasonably conducive for a depression or storm to form.

A dip is the jet stream will come along and propel the system north later today, toward the northern Gulf coast.

The computer forecast models indicate that there is a small window of time that the system can organize with a kick from the jet stream dip. Systems that develop with the help of the jet stream often start out as subtropical depressions or storms because there is cold air aloft involved, in addition to the energy from the warm water of the Gulf. The distinction isn’t important to the final weather that people along the northern Gulf coast will experience.

The upper-level winds are forecast to be very hostile when the system arrives at the northern Gulf coast early in the weekend, so it’s not expected that the system could get terribly strong.

Still, with top winds at 40 mph or a bit higher, there’s a good chance it will start out as Tropical Storm or Subtropical Storm Nestor.

The main effects will be heavy, gusty rainstorms from about the New Orleans area east to North Florida and elevated tides along the coast in the same area. A good part of the South is experiencing an extreme drought, so the rain will be beneficial – up to a point, of course.

As always, forecasts for developing systems are less certain than for well-organized tropical storms or hurricanes, so changes are certainly possible. With the strong upper-winds likely, however, no big storm is expected.

The Key Messages from the National Hurricane Center on the system are:

1. Dangerous storm surge inundation of up to 5 feet above ground level is possible along the Florida Gulf Coast from near Apalachicola to Clearwater, where a Storm Surge Watch is in effect. Residents in these areas should follow advice given by local officials.

2. Tropical storm force winds are likely along portions of the north-central and northeastern Gulf Coast where tropical storm watches and warnings are in effect. Regardless of the exact track and intensity of the system, these winds will cover a large area, especially east of the center, and begin well in advance of the arrival of the center.

The only significant effect in South Florida will be to help keep any fall cold fronts away for a while longer.