Major Hurricane Ida

[thunderbolt]

No Major???

[MUWX]

Just now, thunderbolt said:

No Major???

Forecasting a major in the initial forecast is unprecedented. This initial advisory is about as aggressive as they ever get. 

[Yeoman]

Hopefully it gets to a cat 5 right before landfall

[csnavywx]

Just now, MUWX said:

Forecasting a major in the initial forecast is unprecedented. This initial advisory is about as aggressive as they ever get. 

Pretty much this. It's already an aggressive forecast. Warranted, mind you, but already explicitly forecasting RI.

Having said that, the LLC got going in a hurry this morning and we're already on the northern side of the guidance envelope (from yesterday's runs), so -- not great news. We'll get Cuba as a speed bump at least, but I'm not sure how much that's really going to help. The "good solution" space is even narrower than yesterday.

[WxWatcher007]

7 minutes ago, CheeselandSkies said:

...and that leaves room for further intensification with 24 hrs between forecast points.

By then you’d likely have to consider what the internal structure is doing, i.e. eyewall replacement cycle.

[Porsche]

Strengthening towards landfall.

[Amped]

There's a possible Fujiwara effect with Nora, assuming Nora hit land and dissipate.

[Windspeed]

Yuck...

[Amped]

It's a lopsided storm, so the strongest winds go right over New Orleans.

 

[CheeselandSkies]

9 minutes ago, Amped said:

It's a lopsided storm, so the strongest winds go right over New Orleans.

 

It's not lopsided...that's typical wind distribution for a well-formed hurricane.

[Amped]

8 minutes ago, CheeselandSkies said:

It's not lopsided...that's typical wind distribution for a well-formed hurricane.

It was a bit lopsided coming into the southern gulf.  It wrapped up before landfall so I admit that was a poor choice of words.

[nycwinter]

another dreaded i storm.upcoming..

[40/70 Benchmark]

41 minutes ago, WxWatcher007 said:

By then you’d likely have to consider what the internal structure is doing, i.e. eyewall replacement cycle.

I am preparing my first look right now...my initial inclination is that there won't be much time to undergo an ERC relative to if this had struck the NW corner of the GOM....this is a bit of good news with respect to surge potential, and potentially dire in terms of wind.

[40/70 Benchmark]

47 minutes ago, csnavywx said:

Pretty much this. It's already an aggressive forecast. Warranted, mind you, but already explicitly forecasting RI.

Having said that, the LLC got going in a hurry this morning and we're already on the northern side of the guidance envelope (from yesterday's runs), so -- not great news. We'll get Cuba as a speed bump at least, but I'm not sure how much that's really going to help. The "good solution" space is even narrower than yesterday.

Aggressive is the way to go here.....you need to properly convey a cataclysmic sense of urgency here because there is a very realistic chance at such an out come. That Henri BS was not the time to lay out worst case scenarios because it was always highly unlikely....in this case, it is not unlikely. 

[40/70 Benchmark]

What I would hope for if I lived in Louisiana, short of Lake Ponchetrain spontaneously filling over the course of the next 84 hours, is for IDA to have a very small circulation, which would expedite the evolution and perhaps make an ERC more likely and also minimize surge, as well. If this thing has a large circulation, forget....good night.

[Ed, snow and hurricane fan]

3 hours ago, Dunkman said:

This is not a good take. I grew up on the coast and we dealt with many hurricanes. Whether or not to evacuate is a difficult, complicated decision in many cases.

New Orleans has a fair number of older and disabled people, and a large number of poor citizens who rely on relief checks.  My understanding, part of the lack of evacuation before Katrina is people didn't have the money for gas or hotels.  It is August 26, people on a fixed income will need rapidly organized public transport like buses.

 

I'm governor of Louisiana, I cancel schools tomorrow statewide, and have all busses gather somewhere so they can deploy to New Orleans (or Lake Charles, or coastal towns like Houma or New Iberia) and get the people out who can't get out themselves.  Reliant Stadium in Texas or Minute Maid Park, a few baseball games rescheduled isn't bad and the public good will for the Texans and Astros...

[andyhb]

Here's a link to the folder for the SHIPS text files for those interested.

https://ftp.nhc.noaa.gov/atcf/stext/

The ones you'll want to use for this storm are entitled/formatted: "YYMMDDHHAL9921_ships.txt", where YY is year, MM is month, DD is day, and HH is hour of issuance.

Probs for 65 kt/72 hr RI for TD9 are already fairly high and I'd imagine they will rise.

 

[Ed, snow and hurricane fan]

6 minutes ago, 40/70 Benchmark said:

What I would hope for if I lived in Louisiana, short of Lake Ponchetrain spontaneously filling over the course of the next 84 hours, is for IDA to have a very small circulation, which would expedite the evolution and perhaps make an ERC more likely and also minimize surge, as well. If this thing has a large circulation, forget....good night.

850 mb GFS PW forecast, TD 9/Ida ingests the dry air, below 1.5 inch PW, and just eats it.  It just expands the higher PW field around it as it comes Northwest, I don't think dry air holds this to an Andrew sized cane.  ERC tend to expand the windfield.

[Amped]

I can roughly make out the center of circulation.  It looks closer to the southwest tip of Jamaica than what models initialized.

[WxWatcher007]

6 minutes ago, 40/70 Benchmark said:

What I would hope for if I lived in Louisiana, short of Lake Ponchetrain spontaneously filling over the course of the next 84 hours, is for IDA to have a very small circulation, which would expedite the evolution and perhaps make an ERC more likely and also minimize surge, as well. If this thing has a large circulation, forget....good night.

This. The small core scenario makes an ERC more likely, but the mere fact that we’re grasping for inhibitors to a high end event tells us all we need to know. 

[40/70 Benchmark]

7 minutes ago, Ed, snow and hurricane fan said:

850 mb GFS PW forecast, TD 9/Ida ingests the dry air, below 1.5 inch PW, and just eats it.  It just expands the higher PW field around it as it comes Northwest, I don't think dry air holds this to an Andrew sized cane.  ERC tend to expand the windfield.

I understand that...what I mean is that a smaller system offers less surge potential, so smaller circulation, while also being more prone to a faster ERC to lower wind, would also inherently have less surge potential. But yes, ERC do increase surge potential relative to each individual storm.

[40/70 Benchmark]

7 minutes ago, WxWatcher007 said:

This. The small core scenario makes an ERC more likely, but the mere fact that we’re grasping for inhibitors to a high end event tells us all we need to know. 

Absolutely....only hope for LA is intensity nuances due to internal processes, and track nuances that could focus most severe impacts over marsh land. We saw that with respect to surge in Laura, and wind in Andrew.

[Windspeed]

AF301/TEAL71 has taken off and is en route to TD9.

[Windspeed]

Interesting that the 12z GFS is now lifting Tropical Storm Nora in the EPAC into the Mexican coastline and dissipates by 54 hours. This would be around noon Saturday. Again, this is just one global model solution; however, if there were going to be downstream upper level influences between the potential GOM hurricane, the decaying PV feature over the western GOM and the upper outflow pattern that would have a detrimental impact on TC intensity, you would at least want a strong EPAC TC near the Baja. By 78 hours, the GOM TC is bearing down on landfall with limited interference from upper level westerly flow. The ECMWF may have a completely different outcome for Nora than the 12z GFS, but it is an interesting development. Further still, the decaying PV feature leading into this may be wedged enough in-between Nora and future-Ida for Nora's presence/intensity to not even matter.

[Windspeed]

Per ATCF best track, TD9 has now become Ida.

AL, 09, 2021082618, BEST, 0, 177N, 794W, 35, 1004, TS, 34, NEQ, 60, 40, 0, 0, 1009, 150, 50, 0, 0, L, 0, , 0, 0, NINE, M,

[40/70 Benchmark]

Just now, 40/70 Benchmark said:

Top ten natural disaster in the making IMHO.

 

https://easternmassweather.blogspot.com/2021/08/developing-ida-poses-potentially.html

 

[Cyclone-68]

How does New Orleans come back from this (if they do at all?)

[MUWX]

1 minute ago, Cyclone-68 said:

How does New Orleans come back from this (if they do at all?)

We have a long time to go before we need to start calling for the death of N.O. 

[Windspeed]

We have a long time to go before we need to start calling for the death of N.O. 

Exactly. Additonally, please take the gloom and doom posts to the banter thread. Too much uncertainty to be making posts like these three days out. If it comes to pass a worst case scenario is unfolding, there will be plenty of gloom to be had. Again, for now there's just too many unknowns.

[cptcatz]

5 minutes ago, Cyclone-68 said:

How does New Orleans come back from this (if they do at all?)

Zeta's eye went right over New Orleans last year after making landfall with winds of 115 mph. Seemed like New Orleans was barely affected by Zeta though. Why were the effects minimal in Zeta but expected to be catastrophic with this?