Official Hurricane Irene Live OBS/Discussion Part II

[jconsor]

It's a good thing the Euro has a marked low bias on pressure. My guess for the landfall pressures:

NC: 947 mb

LI: 960 mb

good lord

[ORH_wxman]

When it gets to metro area?

About 968mb, which is a cat 1 most likely.

[CAT5ANDREW]

This question is probably too specific-- but do you have any ideas as to how hard the wind has to be to blow windows in?  These windows are fairly new (less than 10 years old) but pretty large (60" or so.)

Last yea during the macroburst my big living room window bent inward some with 100+MPH winds.It all depends what direction it faces.

[Sickman]

944 mb= close to a cat 4

No.

[nzucker]

About 968mb, which is a cat 1 most likely.

It is 944 over Asbury Park, that's definitely NYC metro territory.

[ORH_wxman]

It is 944 over Asbury Park, that's definitely NYC metro territory.

I have no idea what maps you are using, but its nothing close to that pressure near NYC on the WSI maps...I actually misread them, its 964mb, which is still probably a cat 1, but possibly a cat 2 depending on wind field distribution.

[earthlight]

I have no idea what maps you are using, but its nothing close to that pressure near NYC on the WSI maps...I actually misread them, its 964mb, which is still probably a cat 1, but possibly a cat 2 depending on wind field distribution.

Well, to his defense, I posted the wundermap graphics..which zoomed in show a 944 MSLP over Asbury Park. But I'm not sure where at Cat 4 came into discussion...and the graphics on StormVista also show the 964mb you're talking about.

[ORH_wxman]

Well, to his defense, I posted the wundermap graphics..which zoomed in show a 944 MSLP over Asbury Park. But I'm not sure where at Cat 4 came into discussion...and the graphics on StormVista also show the 964mb you're talking about.

Wunderground is obviously wrong...that is pretty unrealistic.

[earthlight]

Wunderground is obviously wrong...that is pretty unrealistic.

I knew that ECMWF couldn't offer us free accurate data

[ScottB]

I knew that ECMWF couldn't offer us free accurate data

And when it does, well, obvious utter destruction occurs. Save it for the winter please.<3

[anemone]

for people poo-pooing TS-force winds, we only saw sustained winds into the 50s or so during Isabel in DC (I believe we had a few gusts to around 70) yet damage was significant. Not to structures themselves, but there was heavy damage of trees & very significant power outages. I've noticed the threshold for significant tree damage (in my experience) is around 70mph winds (even just in gusts), and if Irene does take the forecast track there is a very decent chance NYC proper could see hurricane-force gusts.

I'll likely be riding out the storm at my friend's place in Greenpoint (on the surge maps it's one of the islands that would appear if a 4 came in, near McGolrick Park) rather than the UWS as conditions will likely be more observable/severe in Brooklyn. Very excited, although the destruction of Ikea is going to suck.

I live a few houses north of Franklin Ave, just outside of Zone A. I'll be at my bandmates' place on North 7th and Driggs in Zone C. Their basement might flood, but they have no windows on vertical walls.

Watch out for the big trees in McGolrick. You should take some before and after pics of the trees with and without leaves.

[jconsor]

Wunderground is obviously wrong...that is pretty unrealistic.

I don't think wunderground is wrong. It's probably higher resolution than the Stormvista or WSI maps. The wunderground map agrees exactly with Allan's site on the MSLP at 48 hours - 926 mb. In any case it's almost a moot point because we all know about ECMWF's marked low bias on MSLP for hurricanes north of 30N.

[Zir0b]

6z early guidance...noticable shift east

[A-L-E-X]

Usually over 80 mph, if its a ground floor house its quite unlikely you'd lose windows in a Cat 1 or even weak Cat 2 storm, especially if you have alot of structures obstructing wind. High rise apartments in Queens and Bklyn facing east or southeast could easily lose windows though.

Thanks SG, I assume the same applies to 2nd story bedroom windows? So I have to look out for 80 mph gusts

[ORH_wxman]

I don't think wunderground is wrong. It's probably higher resolution than the Stormvista or WSI maps. The wunderground map agrees exactly with Allan's site on the MSLP at 48 hours - 926 mb. In any case it's almost a moot point because we all know about ECMWF's marked low bias on MSLP for hurricanes north of 30N.

That might be proof that WSI is more accurate...if some maps are showing extremely low pressure that is obviously biased too low...then we can say WSI is more realistic to reality. Maybe those extremely hi res ECMWF plots are just not viable for operational forecasting....just throwing that out there.

[A-L-E-X]

I have no idea what maps you are using, but its nothing close to that pressure near NYC on the WSI maps...I actually misread them, its 964mb, which is still probably a cat 1, but possibly a cat 2 depending on wind field distribution.

The same maps that show his elevation to be 2,000 feet

[A-L-E-X]

Apparently, the storm is wobbling back to the west.

[tornadojay]

&lt;b&gt;&lt;/b&gt;6z early guidance...noticable shift east&lt;b&gt;&lt;/b&gt;&lt;b&gt;&lt;/b&gt;&amp;lt;img src=&amp;quot;http://raleighwx.americanwx.com/models/atcf/06zatcfearlyinvest2best.gif&amp;quot; /&amp;gt;&lt;b&gt;&lt;/b&gt;&lt;b&gt;&lt;/b&gt;

What is interesting to note about these slight shifts is that the clustering of model concensus still remains tight even with the shifting. What that tells me is that the synoptic pattern is probably pretty locked in and the models all agree which direction to take the storm. The shifting might actually be due to actual initialization of the storm at that given time. Remember that the structure of the storm has been evolving and the eye has gone through some replacement cycles. It's possible that the actual center could be slightly east of where the models perceived it was gonna be 6 hours ago simply based on how the storm has been organizing itself. The same adjustment back to the west can most likely easily occur as well. Theoretically you would not expect major jumps at this point but just baby steps.. But I guess even a few baby steps in one direction or the other could make all the difference in the world for someone.

[A-L-E-X]

<b></b><b></b><b></b>What is interesting to note about these slight shifts is that the clustering of model concensus still remains tight even with the shifting. What that tells me is that the synoptic pattern is probably pretty locked in and the models all agree which direction to take the storm. The shifting might actually be due to actual initialization of the storm at that given time. Remember that the structure of the storm has been evolving and the eye has gone through some replacement cycles. It's possible that the actual center could be slightly east of where the models perceived it was gonna be 6 hours ago simply based on how the storm has been organizing itself. The same adjustment back to the west can most likely easily occur as well. Theoretically you would not expect major jumps at this point but just baby steps.. But I guess even a few baby steps in one direction or the other could make all the difference in the world for someone.

So the models might just be making adjustments based on short term wobbles? Interesting!

[tornadojay]

So the models might just be making adjustments based on short term wobbles?  Interesting!

I think it is plausible just because of the fact that the whole clustering scheme seems to remain in tact. If that started to diverge, my guess would be that models are picking up on something synoptically that is impacting the steering of the storm.. That subtle change would cause larger deviations over time. I think the initialization scheme of the hurricane at any given point of time could be a big factor.. A lot of parameters to consider

[tornadojay]

<b></b><b></b><b></b>I think it is plausible just because of the fact that the whole clustering scheme seems to remain in tact. If that started to diverge, my guess would be that models are picking up on something synoptically that is impacting the steering of the storm.. That subtle change would cause larger deviations over time. I think the initialization scheme of the hurricane at any given point of time could be a big factor.. A lot of parameters to consider

Of course.. On the flip side.. I suppose the even just each models ability to initialize the storm could be an impact as well

[A-L-E-X]

I think it is plausible just because of the fact that the whole clustering scheme seems to remain in tact. If that started to diverge, my guess would be that models are picking up on something synoptically that is impacting the steering of the storm.. That subtle change would cause larger deviations over time. I think the initialization scheme of the hurricane at any given point of time could be a big factor.. A lot of parameters to consider

I saw the same thing too and something that really seemed interesting was how it looks so much like a probability chart, with the outliers further away in both directions while the majority were clustered in the middle-- it is so damn symmetrical it almost looks artificial The funny thing is the "middle" of all the tracks is empty, with two clusters around it (with exactly the same number in both directions and with each side almost mirror symmetrical with the other-- including the outliers!), which was also the case before when it was further west. That's why it looked almost artificial to me lol. The middle was over NYC and now it's over western Long Island.

[tornadojay]

Yea.. Definitely.. It'll be interesting to see how much deviation ultimately occurs between now and game time. The storm is so large though that the probability of seeing hurricane force winds across much of the immediate NYC metro area seems pretty high.

[A-L-E-X]

Yea.. Definitely.. It'll be interesting to see how much deviation ultimately occurs between now and game time. The storm is so large though that the probability of seeing hurricane force winds across much of the immediate NYC metro area seems pretty high.

I was just reading about this in the main forum-- the largest wind field since Ike! That's really saying something. The surge will be amazing with this and it wont weaken quickly either.

[SnowGoose69]

06Z NAM looks like a twin forks landfall.

[Dsnowx53]

06Z NAM looks like a twin forks landfall.

Yes it is. It's essentially identical to the 0z NAM, just a tad slower.

[SnowGoose69]

Yes it is. It's essentially identical to the 0z NAM, just a tad slower.

I definitely notice more of a NE motion though from VA on northward than I did with the previous few runs.

[nycsnow]

Hurricane watch NYC

[Allsnow]

Yes it is. It's essentially identical to the 0z NAM, just a tad slower.

Yeah just compared and its spot on....perhaps a hair wetter.......

[Allsnow]

through 36 hrs the 06z gfs is def a bit further west