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Hurricane Sandy OBS (Part ii)


Alpha5

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Fellow medical student here (4th yr at NYMC). I live in manhattan and was watching the drama unfold. I applaud all the heroic efforts to evacuate patients. On a larger scale, I think the effors of ALL first responders from the nj coast through ct was simply astounding. People risked their lives left and right for strangers. It was special to see and this region will really band together to hopefully restore normalcy as soon as is physically possible.

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Sure.

So lets start with the basics. How do we mix higher winds down from aloft? That's when we look at soundings. Soundings allow us to look at the atmospheric profile and gives us a sense of how the atmosphere is laid out...which eventually may tell us how it will behave. In order to mix down stronger winds from a certain level, you must make sure there isn't an inversion. An inversion is a layer of warmer air aloft where the temperature would actually warm as you went higher in the atmosphere. In this example, there is no inversion in the lower levels. This was the OKX soundings at 8pm or 00z.

How do we know there is no inversion? Look at the red line, That is the temperature of the atmosphere as you go up in altitude. To the left is the pressure in millibars. The lower the pressure, the higher up you are. On the bottom we have temperature in Celsius. So, lets follow this red line. As we go up below 850mb, notice how quickly the temperature decreases with height. That means a parcel as the potential to rise from the surface. Now on the right notice the wind barbs. That is 80 to 90 kts of wind right there. So now we have established that air will rise and we have strong winds just off the deck. Who cares, the air is rising right? What does this mean. Well here is the thing. In the atmosphere, if you are unstable..many times you'll get turbulent low level eddies. This means as air is rising, air also sinks. This is called mixing. So here is the deal, you had plenty of air trying to rise, but also turbulent eddy mixing allowed air to also sink. The sinking air carried with it strong winds from aloft. This is how we were able to mix down these ferocious winds.

I kept this simple without getting to detailed with soundings, but basically that sounding is about as unstable as you will ever see in an environment like this. I've never seen anything like it. This was also well modeled.

Awesome post! For anyone who hasn't taken a boundary layer meteorology class, he explained a nice compact way as to why the entire NE side of the storm rocked and the entire SW side blew chunks. Turbulent eddies above a stable layer will never let you get big wind gusts, when an inversion occurs you are basically cut off from the low-mid level flow. It acts like a lid. Entire SE side had that warm tropical air blowing in with the upper level support sliding over to provide a very unstable environment and one that was capable of transporting those high FL winds down. The SW side that had the cold air blowing in really didn't live up to they hype most locations barely reached lower end winds gusts. (Unless you were close to the center) They basically were dealing with the lowest 0-50 meter winds with little to no mixing.

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First of all so sorry to everyone who had damage to their properties, it's really heartbreaking to see all the destruction.

Just hoping someone can help... Anyone from the Ridgewood, NJ or Hohokus or Paramus area? I'm heading down there for a funeral this weekend. I've been told to expect no power, and also told that gas stations are basically out of gas and filling up involves waiting in very long lines and rationing so I should just make sure I have a full tank of gas before I enter NJ.

I'm just trying to plan on how prepared to be and what gear I should bring with me since from what I've been told so far, it's pretty bad.

I live in Ridgewood, NJ. Power is sporadic but slowly coming back, about half the town is still out. If you don't have a place to stay, just about every hotel within a 60 mile radius that has power is book solid for a week. Gas stations are slowly opening up (using generators). My wife came back from Boston on Tuesday night and was unable to fill the car up within 75 miles of home. None of the stations were open. But that was Tuesday. I filled up my car tonight and it took me about a 20 minutes to get gas. No rationing. Little by little, more and more stations are opening up. Yesterday, I saw 2 stations open and the lines were at least 1 hr long (60 cars deep), today there were at least 20 open and the lines were much shorter (20 cars deep).

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