Another Message from Roger Smith, a Forecaster I Respect Very Much

Again, the following is from Roger Smith, a forecaster that I respect very much:  

06z RGEM (to 48h) does nothing to change 00z GGEM scenario.

06z GFS still has the implausibly wide hook well into the blocking high. Don't see that happening really.

Euro on the other hand seems to have over-adjusted. I agree with the Long Island landfall theory and would say west-central LI to sw CT to BGM the most likely track.

With a 950 mb centre making landfall, I would expect impacts to be fairly bad even in NYC on the marginally back side of the track. Margin of error is too close at this time range anyway but for sake of argument, a 950 mb landfall south of ISP tracking to 20n LGA would imply winds steadily increasing from NE backing to NNW across metro NYC and mostly in the 50-80 mph range. Winds on the strong side of the low would probably peak at 80-120 mph. This would imply a 15-25 ft storm surge trending to 5-10 ft around NYC.

Just rough estimates for a track that is not anywhere near determined. The basic idea is that whoever finds themselves between the landfall point (or 30west of it) and the 970 mb contour on the strong side can expect damage for sure, otherwise it's more hit and miss depending on channelling and precip phase (heavy snow will cause damage in PA MD WV at any wind speed where trees are still carrying their leaves).

I see the point being made about perhaps the sluggish forward speed could allow weakening but the GGEM scenario shows a complete phase with a 528 dm upper low and 952 mb surface low, to me that spells 80-120 mph wind max zone over parts of LI and 60-100 mph in s CT. I hope I am wrong and that this storm does reasonably little damage, but I have a very strong feeling that unless the models totally bust, it will be high impact, much higher than Irene for sure except in VT and north of Albany.

The current Euro scenario is very nasty looking for NJ and NYC, and would imply a more variable wind field because the system would be pulsating due to multiple land interactions, I would imagine the wind record at JFK for example in that kind of track would show big oscillations from 40 to 110 mph. There would be a totally weird looking wind field over NJ, something like north 30 mph at Trenton, east 60 mph at Newark, SE 80 mph at Asbury Park and perhaps ACY into the eye, Cape May veering to SW 50-80, just to illustrate rather than try to predict. This will have a calm center of about 20-30 miles in diameter, almost in any scenario.

The worst possible track for impact, I would conjecture, is directly across New York City from 140 deg. This would combine wind damage in a heavily populated area with large storm surges over a wide area.

Anyone reading this, please bear in mind, just one opinion out of hundreds, caveat emptor. The big challenge will be nailing the impacts in time to provide the best possible warnings rather than over-generalized warnings that won't identify the exact risks. I have to imagine from what I read on here that the broadcast mets in the northeast U.S. have the full attention of the general public and that will save a lot of lives if this comes in strong. Saving property is more of an individual's early planning that almost has to take place before risks are nailed down. Any prudent person would be thinking of moving valuable items out of harm's way (taking into account the wider range of places where harm could fall). I mean, why wouldn't you, we have nothing better than these computer models unless Nostradamus shows up and says landfall 20 east of Fire Island.