The above composite image of the Tropical Atlantic shows Tropical Depression Lisa over the far East and Tropical Depression Matthew decaying over Central America (while dumping massive amounts of rain).
The yellow encircled area to the immediate right of Matthew indicates the location of a tropical disturbance developing off of the Yucatan Peninsula. This area of development has been hinted-at by computer forecast models for nearly a week now. At the time it first appeared on the forecast models it was hard to tell whether the system would be the result of the remnants of Matthew, or a newly formed storm. At this time, things are obviously starting with a newly formed circulation to the Southeast of the Yucatan, however the computer forecast models still hint that the two may merge at some point early this week.
Below is the Global Forecast System (GFS) model forecast valid at 7pm Central Daylight Time (CDT) this evening. I have encircled Matthew in purple over Central America (in the bottom left corner of the image):
Below is an image from the same forecast model valid at 7am CDT on Tuesday. Note that within the area encircled in purple we have what appears to be the remnants of Matthew about to merge with the newly forming tropical disturbance off the Yucatan Peninsula:
The next image below is the same forecast model, this time valid at 7pm CDT on Thursday evening. By this time, the Matthew/Yucatan combination system has moved North/Northeast into the southeast U.S. (being drawn into a rapidly moving trough of low pressure), again noted by the purple encircled region. Meanwhile, yet another system is forecast to be developing off of the Yucatan Peninsula, this time noted by the red encircled region:
By 7pm CDT on Sunday (October 3rd), an area of disturbed weather (presumably the same disturbance noted above) off of the Yucatan Peninsula (again encircled in red) is gaining strength and beginning to lift North/Northeast toward Western Cuba:
Needless to say, the region off of the immediate coast of the Yucatan Peninsula has been a hotbed of activity this season, and the next week to 10 days promises a continuation of that trend. Below is an image from "Google Earth" showing Tropical Storm & Hurricane formation points during the month of October from 1851 to 2007. You can see that this "hotspot" off of the Yucatan Peninsula typically remains active into the final month of the "official" hurricane season each year: