we're near the climatological peak of the season. pattern is continuing more or less like it was in august, but mjo is switching to slightly mitigating. activity still occurs on the downturn, so the active waves in the atlantic right now have modest chances at development. soi is pulsing, and when it does that you tend to get delayed-response activity in the atlantic, if other enhancing factors are in place... (enso neutral, early september, warm ssts everywhere.. yeah, thats enhancing).
so anyway, lee is looking flimsy, interacting with an upper trough and a couple of nontropical lows to its west. it may be absorbed by them, absorb them, or just weakly rotate around them. we've had storms not classified as such on a t-2.5 rating before, so the nhc's attitude is again inconsistent. lee has convection, but it really isn't any stronger than it's sheared cousin to the south, 91L.
91L has a t-2.0, and that's with a good deal of shear. factor in that shear results in an underestimate of strength.. well, you do the math. well defined llc with this, and deep convection flaring on and off the core today. the nhc says it isn't organized enough (it's just sheared), so it's a tropical low for now. it's working its way wnw through an upper trough.. and should be getting on the enhancement flank of an upper low immediately to its west, so it'll probably develop... over the next couple of days. nhc seems to be waiting on a sustained burst, based on the TWO lingo.
92L is trucking westward right now, and most modeling keeps it on a much further south track. it has a better chance of getting into the western atlantic and perhaps affecting the ne caribbean next week, but this is highly uncertain. the development chances are modest, as it is at a low latitude. good signature, though, so given a couple of days it may be something.
models are progging a large area of general low pressure from the eastern gulf out to near bermuda.. as part of the pattern pulse/upper weakness trapped south of the large surface high descending from canada in katrina's wake. this sort of pattern generates tropical cyclones near the east coast sometimes... potentially in the gulf, but most likely off the east coast. far enough east and it will likely drift out to sea... closer in a stalled, sheared, slowly developing hybrid type storm would be what we're looking for. most global models indicate something like this will be present around the weekend timeframe.
i don't really have anything positive or useful to say about katrina. staying detached because the facts make me emotional. there are repercussions that will be felt from this storm in aspects of all our lives. but i have no right to complain... for me the coming things are an inconvenience and a drag. folks i enjoy reading... members of our board.. are homeless now. my regrets are for them.
HF 0515z01september