TROPICS UPDATE: WEDNESDAY, OCTOBER 16, 2019
DEVELOPMENT OF A TROPICAL SYSTEM IN THE GULF IS LOOKING MORE LIKLEY. THE TROPICAL DEPRESSION ON THE OTHER SIDE OF THE ATLANTIC HAS FIZZLED OUT.
The computer forecast models are pointing to an organized circulation developing today or tomorrow in the extreme southern Gulf of Mexico – a.k.a. the Gulf of Campeche. The National Hurricane Center is giving the system a moderate chance of developing into at least a tropical (or subtropical) depression.
The evolution of the system is complex. A large area of disturbed weather has been tracking up the spine of Central America the last few days. Within that large disturbance, two circulations have been evident: a weak one on the north side moving from the Caribbean toward the Gulf, and a strong one on the Pacific side paralleling the coast of Mexico.
It appears the system in the Gulf will be some combination of both of those circulations, which will be pulled north by a dip in the jet stream. That dip will also provide some of the forcing to get the new Gulf system spinning. The involvement of the jet stream dip opens the possibility of it technically being a subtropical depression if it forms. But that technicality is not important to the eventual outcome.
The upper-level winds appear conducive for a depression, and the water is plenty warm for an organized circulation to form.
The computer forecast models track the system – whether it has organized or is just a moisture surge – to move fairly quickly to the northern Gulf coast, arriving late in the week or over the weekend.
The forecasts will not be good until these pieces come together a bit more.
TROPICAL DEPRESSION FIFTEEN never really organized very much. It no longer has an organized circulation, so the National Hurricane Center is no longer tracking it.
The notable thing about the system was its location. There are no tropical depressions this far east this time of year in the record book. Normally the far eastern Atlantic is shut down by the middle of October, but a sliver of conducive enough upper-level winds let the depression get going.