Major Hurricane Irma

[Morris]

 

[ncforecaster89]

9 minutes ago, Mountain_Patch said:

I'm reading a few studies, but I still don't know what a large diameter eye means for hurricane strength. If anyone can help me get a conceptual understanding I won't be so lost on reading. 

Example: http://onlinelibrary.wiley.com/doi/10.1029/2006GL027313/full This is a little too scientific for my understanding right now.

In simpliest terms and in general, a smaller eye is typically associated with a higher intensity.  Since wind speed itself is dictated by the pressure gradient over a given distance, a tighter eye generally produces a higher maximum sustained wind.  

With Irma going through an EWRC, the outer eyewall ultimately replaces the deteriorating inner one...causing a lessening of the PG, and a corresponding decrease in the MSW, as well as a larger eye.  

If conditions allow, the new larger eye will attempt to contract once again, and tighten the PG and reintensify, accordingly.   

The main concern of the larger eye resulting from the aforementioned EWRC is an expansion of the hurricane-force wind field,  and potentially an increased surge at landfall.       

[Kelathos]

Is there any chance this ERC fails to produce a healthy IEW? Maybe one can hope it never regains its full strength.

[David-LI]

Read an article that said buildings in Miami Beach, where evacuations are mandatory, could collapse since all that sand underneath will turn into sea. Could that really happen?

[Mountain_Patch]

1 minute ago, ncforecaster89 said:

In simpliest terms and in general, a smaller eye is typically associated with a higher intensity.  Since wind speed itself is dictated by the pressure gradient over a given distance, a tighter eye generally produces a higher maximum sustained wind.  

With Irma going through an EWRC, the outer eyewall ultimately replaces the deteriorating inner one...causing a lessening of the PG, and a corresponding decrease in the MSW, as well as a larger eye.  

If conditions allow, the new larger eye will attempt to contract once again, and tighten the PG and reintensify, accordingly.   

The main concern of the larger eye resulting from the aforementioned EWRC is an expansion of the hurricane-force wind field,  and potentially an increased surge at landfall.       

So in other words large eyes mean nothing in a favorable environment because they'll naturally contract and restrengthen.. Appears this ERC may have come at the worst time. 

[Hoosier]

At 45 hrs, a hair west of 18z run.

[Wow]

0z GEFS mean low has jumped back NE to 6z position very close to MIA

[LovintheWhiteFluff]

3 minutes ago, Kelathos said:

Is there any chance this ERC fails to produce a healthy IEW? Maybe one can hope it never regains its full strength.

The strongest winds are in the outer eyewall, so it's already healthy. 

[Hoosier]

[YetAnotherRDUGuy]

10 minutes ago, David-LI said:

Read an article that said buildings in Miami Beach, where evacuations are mandatory, could collapse since all that sand underneath will turn into sea. Could that really happen?

Can you link the article?

[AlaskaETC]

0z HWRF is another terrible track for South Florida

[Jebman]

20 minutes ago, BlunderStorm said:

Can an 8.0 generate a sizable tsunami? Mexico doesn't need this as they are already under the gun of Katia...

http://www.telegraph.co.uk/news/2017/09/08/mexico-earthquake-magnitude-8-tremor-rattles-buildings-capital/

My apologies for making a dumb mistake, not checking the date on the article I cited, and for Off Topic.

Back to Irma.

[LovintheWhiteFluff]

Check out the size of the eye on the HWRF

 

[Wow]

GEFS ensembles have shifted back NE with more track into SC than GA after running along the FL coast. Watch that NE trough closely.

[Hoosier]

5 minutes ago, LovintheWhiteFluff said:

Check out the size of the eye on the HWRF

 

Crazy stuff.  Good indication how both coasts may get hammered by extreme winds as it comes in, if it has a track similar to that.

[ncforecaster89]

27 minutes ago, Mountain_Patch said:

So in other words large eyes mean nothing in a favorable environment because they'll naturally contract and restrengthen.. Appears this ERC may have come at the worst time. 

Time will tell, honestly, as there is never a guarantee that an intense hurricane will ultimately regain it's previous intensity following an EWRC.   It only takes a subtle difference in either the atmospheric or oceanic environment to induce weakening.  

In the case of H Andrew, an EWRC dropped the MSW to category-four strength as it passed through the Bahamas, but Andrew rapidly reintensified to category-five intensity on approach and through landfall, after completing that EWRC.  Perfect conditions were the primary reason.  

In contrast, H Katrina weakened from a category-five to a strong category-three H following the emergence of an EWRC that combined with a less favorable environment through landfall. However,  Katrina's double-eyewall structure at landfall helped enhance a large storm surge over an immense area of the Gulf coast, as well as powerful wind gusts well inland,  than otherwise would've been the case.  

[shaggy]

7 minutes ago, Wow said:

GEFS ensembles have shifted back NE with more track into SC than GA after running along the FL coast. Watch that NE trough closely.

Maybe what the NAM was seeing is showing up on a few if the gefs members and pulling the mean east? Times getting short for any major changes I would think.

[jaxjagman]

2 minutes ago, TPAwx said:

This needs to be deleted or edited.  The link is from June.  Waves hitting Mexico now.

He just posted the wrong link,last i will post about it

http://www.tsunami.gov/

 

[mfgmfg]

Will there be any issues getting permission to fly into Cuban airspace for recon passes?

[tmagan]

1 hour ago, NJwx85 said:

Irma is rapidly expanding. The outflow now stretches from Central Cuba to the Leeward islands. It's about to carve out an enormous eye.

Probably end up looking like 'Hugo'.

[40/70 Benchmark]

This hurricane has that "skunked" post ERC look to it to me, right now......perhaps that eventually changes, but often times it doesn't once the colder cloud tops within the CDO begin to take on that shredded look.

Often times we wait the rest of its life cycle for that window when it recaptures that rigor, and it just never quite materializes-

Don't get me wrong....I'm not saying its falling apart, but I am doubting a reclassification to a cat 5, assuming it is downgraded, which it should be.

[tmagan]

1 minute ago, mfgmfg said:

Will there be any issues getting permission to fly into Cuban airspace for recon passes?

That use to be a problem up to the 1980's I understand. These days, I believe recon usually has permission from the Cuban government.

[tmagan]

9 minutes ago, 40/70 Benchmark said:

This hurricane has that "skunked" post ERC look to it to me, right now......perhaps that eventually changes, but often times it doesn't once the colder cloud tops within the CDO begin to take on that shredded look.

Often times we wait the rest of its life cycle for that window when it recaptures that rigor, and it just never quite materializes-

Don't get me wrong....I'm not saying its falling apart, but I am doubting a reclassification to a cat 5.

Too often people just see warm SST's as if it were the only determining factor toward intensity. If it were only that easy. 

[nycsnow]

There Was an earthquake before sandy and Irene as well, nam onto something?  all kidding aside I know the nam is probably wrong but it's still crazy how models aren't 100%. Gefs a bit east to

[Chicago Storm]

This hurricane has that "skunked" post ERC look to it to me, right now......perhaps that eventually changes, but often times it doesn't once the colder cloud tops within the CDO begin to take on that shredded look.

Often times we wait the rest of its life cycle for that window when it recaptures that rigor, and it just never quite materializes-

Don't get me wrong....I'm not saying its falling apart, but I am doubting a reclassification to a cat 5, assuming it is downgraded, which it should be.

The first issue with that is the ERC is still ongoing.

[40/70 Benchmark]

Just now, Chicago Storm said:

The first issue with that is the ERC is still ongoing.

I understand that, but the point is that this particular IRC has manifested itself in this manner.

[AlaskaETC]

https://twitter.com/crankywxguy/status/906030889066405888

[bobbutts]

3 minutes ago, AlaskaETC said:

https://twitter.com/crankywxguy/status/906030889066405888

[Kleimax]

Euro out to 24 hours more SW than 12z. Just off cuba coast

[Z-Cast]

Euro SW at 24HR, holding serve with this trend.