Major Hurricane Irma

[HKY_WX]

9 minutes ago, winterymix said:

Would any of the meteorologists here care to share their best guesses about the overall model track shifts?

We've seen an east trend, west trend, east a little bit and now west shift overnight so that Florida landfall

may be just on the left side of Key Largo.  Next collective model shift and why, please?

W/ Harvey the models were a little too far south, showing Corpus Christie Landfall when it ended up going about 25 miles north of there. People are praising it, however the Euro a few days ago had Irma going through Cuba and coming out the SW side into the Caribbean. The euro is the best model, however I wouldn't pay too much attention to its precise landfall point. Given the size of Irma, it's not going to matter as much as some are saying b/c Miami is going to be on the RFQ unless there's a shift east. I think once the turn N starts, we can zero in on a precise landfall point. That's generally how this works. The only thing I'm confident in is this is going to bomb out again at some point. Most likely once it starts to turn N and the outflow channels are enhanced to the N.

[JC-CT]

It mostly just the strength of the ridge to the north and the timing of the turn as to whether Irma tracks closer to Cape Sable or Miami. We still need another 24-36 hrs of runs to know if this is a SW FL or SE FL landfall. The margin of track error keeps both areas in the cone of uncertainty. So anyone in those areas needs to prepare like the worst part of the hurricane will impact their area.

Very true, but it's also worth bringing up again the GFS's consistent NE bias with this storm. I would hedge closer to a central FL landfall right now than a Miami landfall.

To be continued lol

[Paragon]

25 minutes ago, jbenedet said:

Thanks for posting. Is that the closest pass to Miami?

Seperately, the exact track of the eye will never be resolved, and errors inside 48 hrs, can easily be 50 miles or more as a result of nuanced wobbles and mesoscale effects. That said, I think the important take away here is the graze track has lost considerable weight and if the east coast takes a direct hit it will most likely be in the strongest quadrant. 

 

3mb stronger and also 24 hours faster according to that- 36hr difference-12 hr run= 24 hr.

[bluewave]

1 minute ago, JC-CT said:

Very true, but it's also worth bringing up again the GFS's consistent NE bias with this storm. I would hedge closer to a central FL landfall right now than a Miami landfall.

To be continued lol

Yeah, the GFS poleward bias on the track so far has been obvious.

https://mobile.twitter.com/pppapin/status/905821713467936768?p=p

[JC-CT]

Yeah, the GFS poleward bias on the track so far has been obvious.

https://mobile.twitter.com/pppapin/status/905821713467936768?p=p

Latest update

[Morris]

It's only a cat 3 now per recon. I doubt the NHC will bite though at the 8 am update. They probably are afraid of complacency. Let's see what the coming hours will do.

[JC-CT]

And euro

[winterymix]

12 minutes ago, HKY_WX said:

W/ Harvey the models were a little too far south, showing Corpus Christie Landfall when it ended up going about 25 miles north of there. People are praising it, however the Euro a few days ago had Irma going through Cuba and coming out the SW side into the Caribbean. The euro is the best model, however I wouldn't pay too much attention to its precise landfall point. Given the size of Irma, it's not going to matter as much as some are saying b/c Miami is going to be on the RFQ unless there's a shift east. I think once the turn N starts, we can zero in on a precise landfall point. That's generally how this works. The only thing I'm confident in is this is going to bomb out again at some point. Most likely once it starts to turn N and the outflow channels are enhanced to the N.

Thanks, makes sense.  The people trained to do this professionally work out the model biases as we also see in the bluewave post.

I wonder if any of the very high buildings in Miami can have windows boarded up.

[taylorsweather]

24 minutes ago, PackGrad05 said:

I'll be interested to see how the fluctuations in intensity influence the track.  

That won't be a factor at this point.  150mph hurricanes and 185mph hurricanes are essentially the same.  Now if it were a TS versus a cat 5, then yes, there may be differences if the steering flow changes at different levels. 

[OUGrad05]

1 minute ago, Taylorsweather said:

That won't be a factor at this point.  150mph hurricanes and 185mph hurricanes are essentially the same.  Now if it were a TS versus a cat 5, then yes, there may be differences if the steering flow changes at different levels. 

Current recon showing more like 125mph surface winds on the current mission.  The difference between 125, 155 and 185 is an order of magnitude difference on each one of those wind speeds.  But if your point is 150mph is still highly destructive you'd be correct.  It would test the building codes put in place over the last 20 years that's for sure.

[Paragon]

2 minutes ago, winterymix said:

Thanks, makes sense.  The people trained to do this professionally work out the model biases as we also see in the bluewave post.

I wonder if any of the very high buildings in Miami can have windows boarded up.

Down there have some very high quality "hurricane glass" that has layers of lamination between the glass, don't know what the maximum winds they can withstand is (at least 130 mph though and even a sledgehammer), and for every 20 stories you go up, it's an increase of one category of wind.

[rdcrds4]

I thought the new Euro model has it more East now then even the NHC track? I am trying to figure out there track when 3/4 of the models have it well east of where they have it including the GFS and the ECMWF

[Paragon]

2 minutes ago, OUGrad05 said:

Current recon showing more like 125mph surface winds on the current mission.  The difference between 125, 155 and 185 is an order of magnitude difference on each one of those wind speeds.  But if your point is 150mph is still highly destructive you'd be correct.  It would test the building codes put in place over the last 20 years that's for sure.

Plus 150 at surface level is going to be much more than that 50 stories up.

[Ralph Wiggum]

18 minutes ago, JC-CT said:

Very true, but it's also worth bringing up again the GFS's consistent NE bias with this storm. I would hedge closer to a central FL landfall right now than a Miami landfall.

To be continued lol

But question is....will it matter with such a massive eye? NE eyewall could still wreak havoc on major metros even with a track up the center of FL no? Seems to me like it would take a Western FL Coast LF to be the difference between severe damage and catastrophic devastation in the SE FL major metros.

[OUGrad05]

Just now, Paragon said:

Plus 150 at surface level is going to be much more than that 50 stories up.

If you're 30, 40 or 50 stories up in a major hurricane you've got a death wish...

Windfields on the north and east side of this storm are huge.  I'd be curious to see how it compares with the widest hurricanes in the basin.  I'm pleased to see winds come down over night because I believe there's a strong possibility of a strengthening storm at landfall.  High SSTs, high TCHP and perhaps some slightly increasing shear but some of those shear vectors as we near landfall may serve to enhance an outflow channel and aid in some reorganization.  Starting this process from a cat3 or cat4 storm will be much better than beginning intensification from 170mph.

[Morris]

Lowered to 150 MPH by the NHC

[psv88]

Temporary weakening was well modeled by all models.

[Ralph Wiggum]

Just now, psv88 said:

Temporary weakening was well modeled by all models.

As is forecast for rapid intensification right before LF over the Florida Straits. 

[JC-CT]

But question is....will it matter with such a massive eye? NE eyewall could still wreak havoc on major metros even with a track up the center of FL no? Seems to me like it would take a Western FL Coast LF to be the difference between severe damage and catastrophic devastation in the SE FL major metros.

I think so. No question that this looks to be a destructive hurricane no matter where exactly, or even if, it makes landfall in Florida.

But I don't agree with arguments that there is no difference between 170mph winds and 150mph winds, or especially 170mph winds and 120mph winds. The former will cause far more catastrophic damage to a highly populated area, where no buildings are built to fully withstand that high a wind speed.

[Paragon]

4 minutes ago, Ralph Wiggum said:

But question is....will it matter with such a massive eye? NE eyewall could still wreak havoc on major metros even with a track up the center of FL no? Seems to me like it would take a Western FL Coast LF to be the difference between severe damage and catastrophic devastation in the SE FL major metros.

and don't forget the surge, anywhere east of the eye will experience that.

[Mountain_Patch]

People we've still got two days to landfall and this storm just completed an ERC.. I don't understand why you're talking in absolutes. It's as frustrating as you discussing the models it's all subject to change. 

[Paragon]

1 minute ago, JC-CT said:

I think so. No question that this looks to be a destructive hurricane no matter where exactly, or even if, it makes landfall in Florida.

But I don't agree with arguments that there is no difference between 170mph winds and 150mph winds, or especially 170mph winds and 120mph winds. The former will cause far more catastrophic damage to a highly populated area, where no buildings are built to fully withstand that high a wind speed.

Differences between 150 and 170 is splitting hairs but you are right about 170 vs 120.  Even if this is a Cat 3 the surge will be higher than what you typically see with a Cat 3 just because it's been a Cat 5 for so long.

[taylorsweather]

1 minute ago, JC-CT said:

But I don't agree with arguments that there is no difference between 170mph winds and 150mph winds, or especially 170mph winds and 120mph winds. The former will cause far more catastrophic damage to a highly populated area, where no buildings are built to fully withstand that high a wind speed.

If you were referring to my post, I was talking about hurricane intensity influence on track.  In that regard, there is no difference between 150 and 170.  I'm not talking about damage at all.

[Papa Joe]

1 hour ago, Paragon said:

Is that the same general area where the 1935 hurricane reached Cat 5 status?

Based on the interactive NHC track, yes, almost exactly. 

[40/70 Benchmark]

1 hour ago, Paragon said:

It's very difficult to get a storm back up to Cat 5 after it has been there and then weakened some.  Andrew did it, but that was reclassified after the fact.  I think David actually got to Cat 5 three times, but that's an extreme rarity.

Anyway Irma has set some amazing records, it peaked at 185 mph and stayed there for 36 hours, which is twice as long as any other hurricane in Atlantic basin recorded history (David did it for 18 hours.)  You don't expect a storm to stay at Cat 5 all the way to the coast anyway, especially when it becomes a Cat 5 so far away from the mainland.  It'll still have Cat 5 surge damage though, regardless of wind speeds.

 

Yes.

[Mountain_Patch]

1 minute ago, Paragon said:

Differences between 150 and 170 is splitting hairs but you are right about 170 vs 120.  Even if this is a Cat 3 the surge will be higher than what you typically see with a Cat 3 just because it's been a Cat 5 for so long.

It has perfect outflow and high surface temps. Today into tomorrow the hurricane will look its best. With minimal interaction with cuba this won't be a cat 3 long, and likely will rebuild its lost intensity. The only changes occur as it gets in closer to florida.

[Paragon]

7 minutes ago, OUGrad05 said:

If you're 30, 40 or 50 stories up in a major hurricane you've got a death wish...

Windfields on the north and east side of this storm are huge.  I'd be curious to see how it compares with the widest hurricanes in the basin.  I'm pleased to see winds come down over night because I believe there's a strong possibility of a strengthening storm at landfall.  High SSTs, high TCHP and perhaps some slightly increasing shear but some of those shear vectors as we near landfall may serve to enhance an outflow channel and aid in some reorganization.  Starting this process from a cat3 or cat4 storm will be much better than beginning intensification from 170mph.

Some people have the idea that they're going to escape the surge by going higher up- which is really bad for the reasons you stated.  I'm not sure this can get back to Cat 5 again but it's definitely better to have it weakening right now than start intensifying from 170 later on- I'm not sure where that'd lead and really not willing to find out (even from afar.)

 

[Derecho!]

18 minutes ago, rdcrds4 said:

I thought the new Euro model has it more East now then even the NHC track? I am trying to figure out there track when 3/4 of the models have it well east of where they have it including the GFS and the ECMWF

The 0Z ECMWF Ensemble mean and the GFS 06Z Ensemble mean are slightly West, not East, of the NHC Track  - far more tracks over Tampa than Miami. 

[Tullioz]

8 minutes ago, rdcrds4 said:

 I thought at 1st this was a decent site.

This is beyond a decent site. It is probably one of, if not the best, forums dedicated to the weather and meteorology that can be found, and there is a wealth of talent posting here. 

[Papa Joe]

6 minutes ago, Paragon said:

and don't forget the surge, anywhere east of the eye will experience that.

With the storm coming from the south, the reef will mitigate some of the surge. There will still be a complete over wash of the keys from Islamorada east, flooding in much of the middle/lower keys. I worry about the critters at Theater of the Sea (and the two legged critters who don't get out).

The further west it tracks, the "easier" it will be for Miami, but still expect extensive flooding, possibly with over wash of Miami Beach. 

As I mentioned before (and others have mentioned too), this is forecast to go west of Lake Okeechobee, and this will push much of the shallow lake to the northern end (flooding at the north). It will eventually have to slosh back south. 

Water, water, everywhere.