This post by Dr. Simon Atkins is making the rounds thanks to a Drudge link, but after reading it and listening to Mark Levin’s interview with the author, it sounds like he’s perfectly in line with what we knew a few hours ago. In brief:

1. The early fears that this thing might hit NYC head on as a Category 3 or even a Category 4 and tear the city limb from limb have faded.

2. It’s still going to do lots of damage, but apparently massive flooding from storm surges is now the main threat. Gusts of wind should top out at “only” 60-70 mph by the time Irene hits here, but because the storm’s moving slowly, that gives it extra time to blow water from the ocean into the streets and subways.

3. While somewhat less of a threat now, the wind may still pose unique dangers to skyscrapers. I haven’t heard anyone speculate yet that office towers might topple over, but someone tweeted to me earlier that once you get above the 25th floor or so, the storm is one category higher than it is on the ground. Avoid tall buildings at all costs, and in the name of all that’s holy, don’t stand underneath them. Windows will shatter and glass will fall.

Atkins:

o The demise of Irene has already begun. There is no visible eye. The storm intensity is down to 99 mph. This would be a low-end category 2 or a strong category 1 storm, while 36 hours ago some predicted a catastrophic category 4 storm. Air Force Reserve aircraft have found that Irene’s eyewall has collapsed, and the central pressure has risen — rising pressure means a weakening storm.

o The reduction in storm intensity likely confirms that this storm is not going to be as monstrous as it has been publicly forecast to be.

o Yes, it will be windy. However, north of Delaware most hurricane force winds will very likely be gusts, not sustained winds…

o Our internal modeling uses genetic algorithms to emphasize the weaknesses of storms. Remember that storms are energy. Just like people, they all have their own personalities. From the get-go, Irene was not a power storm. Her goal was to become wide, not internally powerful. Personified further, the storm became too big too quickly and it cannot master its own strength.

Here’s Dr. Jeff Masters at Weather Underground, saying much the same thing:

With its eyewall collapsed and just 18 more hours over water before landfall, Irene does not have time to build a new eyewall and intensify. The storm is too large to weaken quickly, and the best forecast is that Irene will be a strong Category 1 hurricane at landfall in North Carolina on Saturday…

By the time Irene arrives on Long Island Sunday afternoon, it will probably have top sustained winds in the 65 – 75 mph range. However, since Irene is such a huge storm–tropical storm force winds extend out up to 290 miles from the center–it has set a massive amount of the ocean’s surface in motion, which will cause a much larger storm surge than the winds would suggest. At 3:30 pm EDT this afternoon, a wind analysis from NOAA/HRD (Figure 2) indicated that the potential storm surge damage from Irene still rated a 5.0 on a scale of 0 to 6. This is equivalent to the storm surge a typical Category 4 hurricane would have. While this damage potential should steadily decline as Irene moves northwards and weakens, we can still expect a storm surge one full Saffir-Simpson Category higher than Irene’s winds when it impacts the coast. Since tides are at their highest levels of the month this weekend due to the new moon, storm surge flooding will be at a maximum during the high tidal cycles that will occur at 8 pm Saturday night and 8 am Sunday morning. Wherever Irene happens to be at those times, the storm surge damage potential will be maximized. I continue to give a 20% chance that a 3 – 4 foot storm surge high enough to over-top the Manhattan flood walls and swamp the New York City subway system will occur on Sunday.

Lots of water coming ashore, which is why NYC evacuated residents in “Zone A” for hurricane threats today. If you’re taking any of this as an excuse not to get basic supplies tomorrow (in case you haven’t gotten them already), you’re an idiot: As you’ll hear, even someone as bearish about the storm as Atkins thinks we’re in for one of the top ten all-time worst power outages in the northeast this week, with millions of people affected. He’s also worried about a “boy who cried wolf” effect on the public next time if this thing proves to be no worse than his estimates — but if he’s right about the power outages, I doubt he needs to worry about that. The idea of a modest Category 1 ‘cane or tropical storm knocking out the electricity for days on end would be quite an omen of what a Category 3 could do if it landed in our lap. In fact, I’ve already ordered my handy-dandy hand-powered emergency radio from Amazon so that I’m ready next time. (So have a lot of you, too — it’s number four in the electronics department overall.) You know the Boy Scout motto. Apply it judiciously. Click the image to listen.