ATL: ISAAC - Post-Tropical - Discussion

[smw1981]

hey Liz welcome to 2K......not saying it cant deepen more but it needs to work out this dry air issue first.

As it looks now... Is there much of a chance of that prior to landfall?

And thank you for your response.

There's always a chance, but in my opinion, it doesn't have time to get too terribly strong unless it stalls or moves west off the coast of LA..

[fasterdisaster]

What are the models seeing that we're not? The HRRR calls for this to begin ramping up quickly in the next 4 hours. How is that going to happen when dry air to the north is still shaving away any convection trying to consolidate over the center?

[Elizabeth]

Thank you all! Ive quite honestly have been at a loss as to what to do about this storm. I live in a Doublewide near Hammond. Have a more substantial building we can go to, and ride out the storm, but I risk not being able to get back home because of a tendency of our road to flood. And I have farm animals that I really cant leave for the period of time it would take for the water to go down.


LOL it really has had me completely clueless

[TSmith274]

Hi all this is my very first post. I would like to start out by saying... THANK YOU ALL! For what you do here!


Ok, I am a complete novice. My only education on this subject is strictly from being a lifelong resident of SE Louisiana, and keeping up with the information coming in throughout the years.


Now to my question....

I cannot seem to wrap my head around the pressure situation of this storm. Here it is at 978 mb, yet still isnt even a Hurricane yet?

I realize that the Pressure/Saffir-Simpson scale relationships are pretty loose. But does this mean that if this storm becomes more compact and better organized, that we would see a more rapid intensification, then normal?

Not necessarily.There are so many variables. There are variables at play that we dont even understand yet. Dry air is keeping him from looking scary and becoming a hurricane. For that we should be thankful. In addition, think about physics... and something like a figureskater. As the figureskater starts his/her spin, that spin speeds up almost exponentially as he/she pulls her arms inward. It is basic physics. Isaac has a very large circulation. Some of it is dry air, which may make him decievingly small in appearance. But he is still a large circulation. Since he is so large, it takes a very long time for the wind speeds to catch up with his low pressure.

Hurricane Camille was one of the most intense hurricanes on record. She had winds of almost 200mph. Why? Well she spun up very quickly due in large part to the fact that she was so compact. As a matter of fact... she was about 1/3 the diameter of Isaac.

[ncweatherwizard]

Part of the reason that the pressure hasn't "translated" to higher winds is because the pressure gradient isn't that large. Low pressure doesn't cause strong winds; it's the difference in pressure over some distance that does. The greater that difference, then typically the stronger the wind.

So in this case, the gradient isn't very strong. The storm won't simply "tighten" and maintain it's current pressure; although, it is plausible that the pressure gradient--and thus likely the winds--will get stronger if the pressure further decreases.

http://www.atmos.albany.edu/weather/difax/3091.gif

[ROCK]

What are the models seeing that we're not? The HRRR calls for this to begin ramping up quickly in the next 4 hours. How is that going to happen when dry air to the north is still shaving away any convection trying to consolidate over the center?

considered he slowed wayyy down and just crawling....he is not going to take the weakness IMO....you can see it here...not much of an alley way....those high are going to bridge and when they do a EURO track / UKMET slow down and drift west might be on the table. EURO barely gets this on shore before heading west....any delay now mean more time over water during the drift.....

current steering

http://tropic.ssec.wisc.edu/real-time/d ... oom=&time=

[MidnightRain]

What are the models seeing that we're not? The HRRR calls for this to begin ramping up quickly in the next 4 hours. How is that going to happen when dry air to the north is still shaving away any convection trying to consolidate over the center?

The models have not recognized the dry air, hence why they had this bombing in the GOM for days now and it obviously never happened. It might still sneak to 64knts prior to landfall, but I can't see this undergoing significant strengthening with almost it's entire north side eroded away like this.

[ROCK]

BTW- those recon fixes are telling.....

[Elizabeth]

Hi all this is my very first post. I would like to start out by saying... THANK YOU ALL! For what you do here!


Ok, I am a complete novice. My only education on this subject is strictly from being a lifelong resident of SE Louisiana, and keeping up with the information coming in throughout the years.


Now to my question....

I cannot seem to wrap my head around the pressure situation of this storm. Here it is at 978 mb, yet still isnt even a Hurricane yet?

I realize that the Pressure/Saffir-Simpson scale relationships are pretty loose. But does this mean that if this storm becomes more compact and better organized, that we would see a more rapid intensification, then normal?

Not necessarily.There are so many variables. There are variables at play that we dont even understand yet. Dry air is keeping him from looking scary and becoming a hurricane. For that we should be thankful. In addition, think about physics... and something like a figureskater. As the figureskater starts his/her spin, that spin speeds up almost exponentially as he/she pulls her arms inward. It is basic physics. Isaac has a very large circulation. Some of it is dry air, which may make him decievingly small in appearance. But he is still a large circulation. Since he is so large, it takes a very long time for the wind speeds to catch up with his low pressure.

Hurricane Camille was one of the most intense hurricanes on record. She had winds of almost 200mph. Why? Well she spun up very quickly due in large part to the fact that she was so compact. As a matter of fact... she was about 1/3 the diameter of Isaac.

Yes that brings to mind lil devils like Andrew and Charley.

[bella_may]

Wind is really picking up here

[TSmith274]

Wind is really picking up here

Yes it really has, hasn't it? Definitely sustained as well... I haven't noticed much in the way of gusts yet.

[Clint_TX]

BTW- those recon fixes are telling.....

STALLED!!!!!!!

[SoupBone]

BTW- those recon fixes are telling.....

STALLED!!!!!!!

OMG it's Slimer from Ghostbusters!

[ROCK]

BTW- those recon fixes are telling.....

STALLED!!!!!!!

I dont think so...wobbles here and there....looks more west wobbles than north

[ROCK]

oh and he is south of the forecast point as well.....

[mpic]

Couldn't sleep, so came here. Am I seeing what I think I'm seeing? Could we have a new possibility?

[ROCK]

Couldn't sleep, so came here. Am I seeing what I think I'm seeing? Could we have a new possibility?

the EURO was interesting...and he is or did make a jog to the left....almost a full degree....that LLC loves that convection to the south.....wants to tuck under it in the worst way....IMO

[mpic]

Will this be a major change or just a wobble? I sure don't want to drive out now.

[ROCK]

Will this be a major change or just a wobble? I sure don't want to drive out now.

could be a wobble in the short term but the a stall and drift west shift is being seen by the NAM, GFS and now Euro....sure hope its not doing it now. Not supposed to until it almost at the coast....

Where is Delta Dog? I am calling you out and it aint for dinner!!!

[TSmith274]

BTW- those recon fixes are telling.....

STALLED!!!!!!!

OMG it's Slimer from Ghostbusters!

Ok this is pretty damn funny. Has anyone else been following Isaac on Twitter? Yep, he has his own Twitter account. It is late... if you want some laughs, google "Hurr_Isaac twitter" on google... good stuff. He has a lot to say