Models are showing a pretty short lifespan for this feature, but I think that's largely due to how they handle the medium-term structural evolution of the system. Once the system goes warm-core (tropical/subtropical) in the model, they are quickly decaying the system. Normally, that'd be what you expect given the cool SSTs. But, models already handle tropical cyclone intensity pretty poorly as it is, especially for those well out at sea; I would not expect them to accurately capture tropical development in the North Atlantic beyond showing a cut-off low acquiring tropical characteristics to begin with. Experience this season bears that out, with Vince, Delta, and Epsilon all good cases toward that hypothesis, especially the latter of the three. I'd expect this system to be with us in 5 days, regardless of the models losing it.
As the NHC/TAFB discussion mentions, the system is a bit too entangled in fronts right now to be threatening for immediate tropical/subtropical development. It is on its way, however. It has subtropical characteristics in the wind field -- strong winds very near the center of circulation, but a rather flat wind profile out from the center of the system, i.e. the winds are still rather substantial as you move away from the inner "core" of the system. Max winds are likely 50-60kt right now, in line with a 990mb pressure, yet still 30-35kt well away from the center particularly to the NE owing to the pressure gradient between it and the 1044mb high Danny mentioned in the previous post. (For reference, see http://manati.orbit.nesdis.noaa.gov/dataimages21/cur_hires/zooms/WMBds122.png. Likely disregard this link after Monday mid-afternoon.)
METEOSAT-8 satellite image: http://cimss.ssec.wisc.edu/tropic/real-time/europe/images/xxirmet7n.GIF. Satellite representation continues to improve, though we're going to need to see a bit more of a break from the front to the north (though it certainly has been getting there) to get a shot at a classified system. Given the strength of that ridge near/just west of the British Isles, I think that'll come with time. The trailing bands to the south/southeast -- proxies for frontal structures -- will need to tighten up and weaken as well.
We'll know within the next two days if we're going to get another system out there this season. I still think we have a better shot than not at getting something, probably 65/35 now. It is certainly a good case for anyone interested in how these things can get going -- very well predicted by the models, near-classic evolution on infrared/WV satellite imagery, tightening of the circulation and wind field (as evidenced by QuikSCAT), ultimately leading to what may be a subtropical/tropical cyclone. I think we'll see an invest put out for this one tomorrow if for no other reason than to get the microwave imagery from the NRL centered over the storm.
After this...I figure this will last for at least another 7 days in the North Atlantic. Nothing is threatening or should threaten in the tropical Atlantic in that time frame (or for the rest of the season, for that matter). Any development beyond that would be much like the last two storms and would likely take another 5 days beyond the end game for this system to even get going. That gets us to Christmas. At the absolute most, we will not get past Eta this season. As noted above, I think we've got about a 65% shot at Zeta. I think we have a <5% shot at Eta (and no shot if the current system does not get classified) and 0% shot at going further into the Greek alphabet. The absolute end of the 2005 hurricane season is coming...really, it is!
(Let's not even think of the possibility of more of these hybrids in January-April to kick off the 2006 season early, either...)
Current Tropical Model Output Plots
(or view them on the main page for any active Atlantic storms!)