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Sandy/Posttrop Phase Thread For PHL Area


phlwx

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why does everyone keep saying these low pressures wont verify? None of the models are close to the pressure of sandy right now. Dropsonde just had 957mb vdm, maybe 960 at surface. This is even before they expected the true strengthening.

Read Tony's post on the physics, but just comparing to the models, the one global (EC) was verifying significantly higher.

We'll see how things lead from here.

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Read Tony's post on the physics, but just comparing to the models, the one global (EC) was verifying significantly higher.

We'll see how things lead from here.

I was just going off LEK post in tropical thread that the models are all two high on the storm pressures right now. this is the euro 850 winds...they say knowck 20-30 mph off for surface

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Just a question though, since this is an extremely rare circumstance, that maybe the models ARE'T overdoing the pressure? Hurricane hunters just found a 957 MB pressure, which would lend itself to I think the lower pressures further north possibly verifying.

They did with Isaac, Irene and a hybrid storm that made landfall in Canada. I forget that name. The perfect storm's and storm of the century lowest pressures were both estimated to be in the mid 960s as a comparison. Regardless as Ray posted surface pressure and winds don't always correlate and reason why they wisely dropped pressures as a barometer of hurricane category strength. Gloria in essence was a category three pressure hurricane with category one winds. This in no way minimizes the obvious damaging threat from this system as strong/high winds are going to last a long time (not to mention the heavy rain and the tidal impact because this stinker just had to coincide with the full moon.)

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Perhaps. Just remember, at 957 mb its still *barely* a cat 1 hurricane. Wind generation is essentially about as efficient as Irene was.

Hunters reporting 76mph winds 100m west of center. Plus, she'll be strengthening coming into the coast.

Still, even Irene during the 2-3hr height of the storm (heaviest rain bands) just here in Delco, plenty of people without power, plenty of trees down.

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Hunters reporting 76mph winds 100m west of center. Plus, she'll be strengthening coming into the coast.

Still, even Irene during the 2-3hr height of the storm (heaviest rain bands) just here in Delco, plenty of people without power, plenty of trees down.

And PHL only gusted to 52 mph during Irene.

Gusts to 65 mph would be significantly worse. My guess is PHL reaches 60, not sure about the 65 though.

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let me ask ray or tony this. say if these 944mb pressure verify, what would this apply then?

Apply? How you mean?

Its not just the pressure. Its also the gradient, and the ability to mix higher winds aloft down to the surface. Like Tony said, they wisely removed pressure as a part of the hurricane ranking system for a reason. A "normal" storm would be cat 3 right now, based on the 957 mb pressure.

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And PHL only gusted to 52 mph during Irene.

Gusts to 65 mph would be significantly worse. My guess is PHL reaches 60, not sure about the 65 though.

I can see that, very realistic.

However, those 2a-3 hrs in Irene's peak, did some damage. The duration of the wind here will be the issue. 50's for 6-12 hrs would be a very bad outcome.

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Apply? How you mean?

Its not just the pressure. Its also the gradient, and the ability to mix higher winds aloft down to the surface. Like Tony said, they wisely removed pressure as a part of the hurricane ranking system for a reason. A "normal" storm would be cat 3 right now, based on the 957 mb pressure.

i was just wondering what a 944mb "potentialy" could have that a 960 mb storm wouldn't

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I can see that, very realistic.

However, those 2a-3 hrs in Irene's peak, did some damage. The duration of the wind here will be the issue. 50's for 6-12 hrs would be a very bad outcome.

yea but also, when irene hit their were more leaves on the tree and we were coming off the wettest or 2nd wettest august ever which aided to it.

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i was just wondering what a 944mb "potentialy" could have that a 960 mb storm wouldn't

Too much fixation on pressure (my fault). In a purely extratropical system we have locally found 80kts of wind at 850mb is a decent trigger for high wind warning threshold (50kt). It really has to do with the pressure fields and isallobaric contribution than the value itself. Its still tropical now, so we're in an apple/oranapple comparison. Without deep convection and or an adiabatic lapse rate, your mixing is not going to be as efficient. Irene's strongest wind gusts occurred after the sun came out on Sunday and we went adiabatic, very few places away from the coast had their highest gusts as Irene approached. I don't know if that seclusion process is going to somehow be able to maintain a guarded convective circle around its center. Water temps are in the 60s and its motion is not on Hazel's scale. Again this does not take away that a landfall in NJ or DE will likely be the new costliest disaster for that state. The winds are staying strong for too long.

NHC gives EMC the pressure value and location for the 12z run, so this drop should be incorporated in the GFS.

At anyrate, really got to go now, so good luck and hopefully you are not spending the rest of this year clearing debris.

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yea but also, when irene hit their were more leaves on the tree and we were coming off the wettest or 2nd wettest august ever which aided to it.

Tomato tomota... Lol.

We're gonna get it good. The duration of 30-40mph winds alone will do some work on our area. I'd say trees are about 30%bare..still plenty of potential there.

Still think leaves clogging drains will be a major issue. Down by Marshall road closer to where 69th street is, is notorious for flash flooding due to to the amount of "free roaming litter" that collects on the drains.

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I'm not understanding the concern about leaves still on trees. Aren't the first non-destructive

gusts into the 30's going strip most of the leaves in short order leaving mostly bare trees when

the real wind gets underway? It's late in the season and most leaves except maybe the oaks and

beeches are ready to go at the first breeze.

Leaves or not though, damage will be extensive. I've got generator gas for about 2 weeks including

what I can siphen out of the truck.

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I'm not understanding the concern about leaves still on trees. Aren't the first non-destructive

gusts into the 30's going strip most of the leaves in short order leaving mostly bare trees when

the real wind gets underway? It's late in the season and most leaves except maybe the oaks and

beeches are ready to go at the first breeze.

Leaves or not though, damage will be extensive. I've got generator gas for about 2 weeks including

what I can siphen out of the truck.

The trees around here swamp/silver maples have about 80 percent of their leaves on them.

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Tom, which trees generally have the shallowest root system? I have a ton of tall pines around my house and am VERY concerned but I heard they have a deep root system. Is this true?

um not etirely sure. The only thing about pines, they may have a deeper root system but they also have a lot of resistance to the wind since they are evergreens. I would make a stab and say its maples? Thats a guess just from seeing the tree guys take out the maples and what not through our course.

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