An intriguing scenario becomes even more intriguing, it seems. It's one thing to be a week out, watching a tropical wave and seeing guidance forecasts for the disturbance to ramp up and head to New England. It gets a bit stale when you're still doing the same thing on Tuesday, and the timeframe in question is Friday night or early Saturday. I'm aware that I've been significantly downplaying this system contrasted with at least a few other media outlets - no mention of potential wind or rainfall amounts in my forecasts yet - but, let's look at this realistically...
There is still a potential for development, but I think we're seeing play out some of the reasons I've been hesitant with this storm - lots of unknowns have been slow to resolve and those unknowns may be playing out as negatives for storm development. The quick overview on this is that it actually looks the best its looked in the last several days on the visible satellite imagery, with a circulation evident, but farther south than any of the initializations in the guidance, south of the eastern tip of Hispanola. The Hurricane Center also notes falling pressures throughout the region, and upper level analysis shows good diffluence aloft. One thing we don't have yet, however, is a surface circulation, at least not evident on surface observations nor on QuikScat satellite derived wind estimates. So, at this point, the circulation is mid-level and has not worked to the surface. Such systems can and sometimes do translate circulations to the surface, but not always.
But
now we're looking at a system that not only has been sitting longer
than the guidance thought it would, but I believe also is farther south
than it's being initialized, since initialization puts the center of
circulation over eastern Hispanola. 
This
means the system may very well move north too late to be picked up by
the upper low over the Mid-Atlantic. If it's missed by the upper low,
it will sail north and then northeast, missing New England to the south
and east. If you read the Sunday prospectus, this was an option I favored as a potential solution, becoming a glorified open wave as it zips north, and as you can see in these latest hurricane guidance products courtesy of Jonathan Vigh, Colorado State University (linked under Tropical Forecast Tools at
http://tropics.nationalweatheronline.com).
The problem is that this is far from settled. I think we're late enough in the game that it 's going to take longer than late Fri Night/Sat AM for it to get here even if it does head toward New England, but if enough convection fires north of Hispanola to revive the surface circulation - which is weak and just north of the eastern tip of the island - the game could still be on. For now, I think we have to turn our attention to a solution that does not include this tropical wave. Therefore, barring any change in the wave or the guidance in the 00Z run, tomorrow morning's forecast will be approached without taking this wave, or most of its associated deep tropical moisture, into account. Is that the right move? Will I change my tune in 12 hours because the playing field will look different?
What are your thoughts on the setup? From the trend in model guidance to the east, to the sluggishness of the system to take shape, to the southward displacement of the mid-level center, I'd be curious to know if any of you share my thoughts on this, or think I'm missing something critical, but this is the best read I have on it right now. That's not to say flooding or several inches of rainfall couldn't result - there's still a dynamic extratropical setup of lingering cool and dry air with ridging wedged over interior New England, and an amazing southeast wind fetch over one thousand miles of ocean from the Central Atlantic straight into New England, enhanced by the pressure gradient between the high going east of us and the low over the Mid-Atlantic. This should set up an impressive overrunning situation that will produce a band of heavy rain, though amounts won't be as high as they'd be if the wave gets involved.
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