FLHurricane.com: Perky Late Season Atlantic: 90L, 91L, 92L

Looks like we're probably going to be discussing these more - and in the main thread Mike just started.

I somewhat concur with you, in that 92L may actually the one closer to being "there" tonight. However, NHC seems all but ready to give 90L the bump any time now... which I can also understand. Also somewhat agree that 91L perhaps has the longer road ahead of it for any significant development. However, all three of these now appear to me to have quite unseasonably decent shots of developing this week, and I would give them all at least 40% chances for popping sometime between now and Tuesday.

A recent ASCAT of 90L (NHC just issuing a 50% chance on it) does show it to be embodied by a very well-defined LLC, with convection sheared and firing off to the east of the center. With shear relaxing, there is indeed an increasingly good chance of deep convection developing over the center.. and thus NHC suggests a tropical cyclone could form... practically at any time now.

Usually this would necessitate their using wording closer to a 70% to 90% chance of development within the next 48 hours... but, the question of just how well this convection will be able to build over the center is uncertain. However, if and when it does so, I would not be surprised to see 90L go strait to being named, skipping any TD or STD advisory.

Tonight's ASCAT Pass of 90L

With regard to 92L, if I were Head of NHC for a Day, I suppose I would probably already have a 50% or 60% up on this feature tonight. NRL and SSD identify 92L at either 22.9N 55.3W or 24N 54.4W, respectively. But I suspect that a more pronounced center of circulation may have been forming all afternoon and tonight in the mid levels, and may actually be drawing in the elongated LLC more into closer and more symmetrical alignment with it ... this mid-level center now being somewhere closer to 24.5N 56W.

Invest 92L

Where I guess we might see things less alike, perhaps, is that it now appears to me that all three of these features are more likely to become basically tropical, than subtropical. The main reason for this is that the process of shedding off their non-tropical origins (at least with respect to both 90L & 92L) are already well underway. And of course, 91L is a juicy, low-latitude tropical wave, to begin with.

All in all, a very impressive last week in any season's October.

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