A weather system developing in the Atlantic northeast of Puerto Rico could turn into a rare December tropical storm.

The Atlantic storm season ended in November but Ron Goodman of the National Hurricane Center in Miami says it's been plenty warm enough for a storm to develop.

The weather system is still hundreds of miles from Puerto Rico but Goodman says forecasters are keeping a close watch on it. It could mean a lot of rain for the Caribbean but for now it's no real threat to land.

Goodman says the latest forecast models show the system continuing to move toward the west for the next three days, which he says should make it "mainly a marine problem."