ATL: ISAAC - Post-Tropical - Discussion

[WilmingtonSandbar]

I'm shocked no one has stated that this sort of looks like a sub-tropical system. The way it is shaped with most of the action to the West and South of the center, it has to look of one.

Someone made the comment a couple days back that this has looked like a sub-tropical storm for quite a while with it's huge wind and rain shield.

[PTPatrick]

I agree with much of what he says...but I take issue with his mentioning of "category X surge"....I don't think speaking of surges in terms if safir Simpson scale is doing any body a service. I also don't think referring to pressures as being "a category 3" pressure. I know they stopped using pressures in SS scale but they live on in vernacular. I think after the storms we've endured in the past 10 years we've learned much and one is that the safir Simpson scale is woefully inadequate. Pressure/strength relationship depends on size and structure....issac is a perfect example. Size does matter. this could easily push a surge typically associated with cat2's and 3s. Surge also depends so heavily on location and angle of approach. then add duration and tides. It's too complex to assign a category. Nevertheless...average folk still only pay attention the category, not knowing how unimportant it really is.

[Senobia]

Okay. I found a graphic that pretty much sums up Isaac's model runs better than ANY ONE MODEL we have seen to date. Are you ready for it? Brace yourselves.

[Shuriken]

This is the most inexplicable thing I've seen since Barry in 1983.

[DukeDevil91]

This is the most inexplicable thing I've seen since Barry in 1983.

Looks like Barry had the same trouble that Issac is having.

[muscarem]

Why are they finding winds that are much stronger so far south west of the center? I just looked at the google earth tropicalatlantic.com/recon/live page and it is showing several 60mph+ (surface) wind readings over 100 miles Southwest of the center. Anyone else see those?

http://tropicalatlantic.com/recon/live

Install the google earth browser plug-in and check out the latest readings from Flight #29.

[Nederlander]

This has been the most exhausting storm I have ever watched.

I'm guessing you didn't track Ernesto earlier this year? Lol sometimes you have to separate yourself from the tracking for a few hours. Ernesto had me banging my head agains the wall and naysaying the models (as many of us on here were). Turns out the models were dead on with intensity. But it can get highly frustrating when you feel like something should be happening that isn't. Isaac is tricky because he is such a large storm, kind of like Ike in '08. Ike only made landfall as a cat 2 but his storm surge was that of a cat 4. Not saying Isaac's surge will be or won't be that bad, but as far as wind goes, with larger systems, it takes longer for pressure drops to equate to greater wind speeds.

[Meteorcane]

Why are they finding winds that are much stronger so far south west of the center? I just looked at the google earth tropicalatlantic.com/recon/live page and it is showing several 60mph+ (surface) wind readings over 100 miles Southwest of the center. Anyone else see those?

http://tropicalatlantic.com/recon/live

Install the google earth browser plug-in and check out the latest readings from Flight #29.

I would guess because that is where the heaviest convection is located at the moment, allowing transport of winds from upper to lower levels, and also providing some energy for those winds. Also rain rate is high which could skew SFMR measurements.

[Shuriken]

as far as wind goes, with larger systems, it takes longer for pressure drops to equate to greater wind speeds

Katrina had a large windfield as a cat-1 in the south-central Gulf, but intensified to a cat-5 very rapidly after puttering around for a bit.

[fasterdisaster]

75 kt FL, 62 kt SFMR. Right on the cusp.

[cheezyWXguy]

as far as wind goes, with larger systems, it takes longer for pressure drops to equate to greater wind speeds

Katrina had a large windfield as a cat-1 in the south-central Gulf, but intensified to a cat-5 very rapidly after puttering around for a bit.

It was a small system in the south central gulf until it underwent an eyewall replacement cycle. It was much larger after that cycle and thats when Katrina took off. This is nothing even remotely close to that situation in terms of environment, storm size, or storm structure. The only similarity I can find is that they both landfell/will landfall in a similar area on the same day.

[Meteorcane]

I think they may pull hurricane trigger at 2am based on some recent flight level winds.

Edit I didnt realize it was currently 2 (I need to get to bed soon), they probably won't then because recon has not shown a large enough sample size at the moment.

[Extratropical94]

I think they may pull hurricane trigger at 2am based on some recent flight level winds.

I don't think so because they wouldn't have enough time to change the advisories, maybe at 5am though.

[Meteorcane]

Yeah you're right I kind of lost track of time, I should note these winds are also in the NE quadrant where you should expect them, rather than in the SW quadrant maybe a sign of some organization/symmetry although Isaac is trying me thin at the moment as he seems to build up and then fall apart. That being said the pressure has been steadily falling the last day or so.

[wkwally]

looks like nothing new from the NHC so I am off to bed maybe in the AM there will be a hurricane

[muscarem]

They just found a 978mb pressure with the latest dropsonde. I've seen category 2 hurricanes with pressures of 978mb, and Isaac is still classified as a tropical storm. Very strange storm.

[TSmith274]

I really do not understand the references to Katrina. I went through Katrina myself... it is laughable to me. We are very fortunate tonight... dry air has been our savior. Later today into Wednesday will be rough, but we'll be fine.

[wkwally]

I would nor be shocked if Issac makes it to a cat 2 or waek 3 if it slows down but who knows. from what I last seen the NHC still has it making 2 just before landfall.
Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[wkwally]

I do not think thisPersonal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
is going to be a Katrina only by date

[wkwally]

Something happened to mypost as I was saying I do not think that this is going to be a Katrina only by date.
Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.