Good evening....Is disturbance likely to be Subtropical or Tropical?

The disturbance in the Western Caribbean in the wake of Matthewis integrated into a larger area of low pressure which dominates a good chunk of the Western Caribbean and Central America and is not a separate entity as of this typing. There is a 300 millibar and higher anti-cyclone (upper ridge) over the remnant low or remains of Matthew near the coast of SE Mexico and the Bay of Campeche with outflow over the disturbance in the Western Caribbean. Winds aloft over the Western Caribbean are light however increasingly hostile as you move towards the SE USA..

The evolving pattern over the Eastern United States is quite complicated beginning with the upper cutoff low centered over the border of Southern Illinois and SE Missouri. It is forecast to be near the border of N AL and S TN in 24 hours and begin to fill and lift NE slowly in the days ahead; however a strong shortwave will dropping into the base of the trough and deepening the trough over the Eastern United States later in the week with this trough extending south and south-southwest to the Yucatan Peninsula. This trough will induce moderate shear all up and down the east coast and FL..

The system will gradually work itself north over the next several days. There is also the possibility we'll be dealing with two distinct systems. I can't rule out the system being tropical to start but becoming extra-tropical and moving up the coast as a non-tropical low or being absorbed by the larger non-tropical low that will form in advance of the upper low now over the Mid-South.

HPC & TPC have expressed low confidence and I share their concern. Mixing tropical and dynamic (baroclinic....temperature gradience over distance in an airmass) is complicated stuff given the depth of the longwave trough over the Eastern US for the next several days and beyond.