Mid-late October sometimes sees a brief, secondary upswing in activity, and we have already seen this with the formation of Hurricane Richard in the Caribbean.

Now, three interesting, late-season features are percolating out in the Atlantic this week - none currently with great odds for development in the near term, but conditions for development could be turning less hostile by the end of the week.

First up, Invest 90L. Originally this disturbance started out as a very late-season, vigorous Cape Verde wave, and very nearly had enough time to become a tropical depression while still way, way out by the Cape Verde islands. 90L has since morphed several times, now in its most recent incarnation as the centerpiece of a fairly well-defined, hybrid, subtropical low, having merged with a non-tropical upper-level low.

Upper-level winds are currently unfavorable for much development, but could become a little less hostile over the course of the next few days, and the National Hurricane Center currently gives this disturbance about a 30% chance of becoming a subtropical or tropical cyclone within the next 48 hours.

Steering currents suggest virtually less than zero threat to the U.S.

Invest 90L

Next up, Invest 91L. Another very potent, late-season tropical wave, and this one running fairly low latitude, so as not yet to be re-curved and/or ripped to shreds, Invest 91L keeps heading west to west-northwest, towards the northern tip of South America.

There is some chance that it stays partially, or even mostly over water, and upper-level winds could become less unfavorable for development over the next few days, and NHC currently gives 91L a slim 10% chance of becoming a tropical cyclone over the next 48 hours.

Steering currents suggest that 91L could be something to pay more attention to for those in the Caribbean over the coming weekend and/or into next week, should it stay over water, and there is actually some tepid model support for this feature, if it should get into the western Caribbean.

While 91L is a long shot for development in the near term, it is much closer to land, and is quite a vigorous wave. As such, it does bear some watching.

Invest 91L

Lastly, Invest 92L. Invest 92L seems to have grown out of some of the remnants of a fairly well-defined central Atlantic low, originally out near 13.5N and 42.5W before encountering detrimental wind shear, and another upper-level trough. This Invest is now situated somewhere around 25N 54W, and appears to be drifting west-southwest, at present.

There is a surprising amount of early model support for this feature, and while unlikely a direct threat to the U.S., it could bring some weather to Bermuda, should it develop. NHC currently gives 92L about a 20% chance of becoming a subtropical or tropical cyclone over the next 48 hours.

Invest 92L