ATL: LAURA - Post-Tropical - Discussion

[cfisher]

https://i.ibb.co/PgV35w0/20200825-161430.jpg

I believe the X is the center. Thoughts?

More or less

[cfisher]

Average 2mb core drop every hour from now till landfall wouldn't be unreasonable. That would be a 918mb landfall

Well the nhc is calling for shear the last 12 hours. They don’t think it will cause weakening but she keep it from intensifying further. That’s best case I guess. Your scenario isn’t far fetched.

True. I just don't think 15-20kts of shear is enough to limit intensification, depending on the core structure and SSTs

[HoustonFrog]

I think the residential communities are 10-15+ miles inland from the coast, so maybe that allows some of the wind sting to slow a bit

I sure hope so. Nobody wants to take 100kts sustained head on so port Arthur is probably one of the better options if it has to hit somewhere at all. It’s gonna be a scary 48 hours for the folks in that general area and it will probably be wide spread power outages as it rolls east across the country.

A lot of them just paid with Harvey and Ike and Rita all I’m the last 15 years. They could use a break.

It's the Moore,OK for hurricanes

[KWT]

They’ll be fairly close to excellent. But with only 30something hours until landfall, it’s not going to have enough time to drop super low. There are some historical exceptions. I believe someone brought up Wilma yesterday. But even if it drops say another 40mb by landfall, that’s still impressive af. Any more than that is a bonus for the storm.

Much depends on just how tightly the inner core can become over the next 6-9hrs. There is a period of time from 9-30hrs out that looks nearly ideal for development and strengthening. If it has got its act really together, a 1.5-2mb drop an hour over that time period should be possible. Add another 9-15mbs drop from the last advisory estimate to 9hrs time and your getting into the high 920s/930s as perhaps a realistic max intensity at this point.

However its still quite early days. I remember in the past going to bed with the likes of Wilma/Charley and waking up to find they were utterly different beasts. Michael also pulled that trick just a couple of years ago. Not saying it will do that of course, just something to be ready for.

[cheezyWXguy]

One of the biggest indicators to me that this is going to capitalize on its environment well is the dual outflow channels that seem to be starting to set up. I think DMAX is going to be productive this evening, and I may be bold, but I am thinking we will have a major by tomorrow morning.

[cfisher]

It will be making landfall near DMAX, right?

[Kazmit]

Average 2mb core drop every hour from now till landfall wouldn't be unreasonable. That would be a 918mb landfall

Well the nhc is calling for shear the last 12 hours. They don’t think it will cause weakening but she keep it from intensifying further. That’s best case I guess. Your scenario isn’t far fetched.

I think if it’s already a well established major hurricane shear will be much less of an issue.

[GeneratorPower]

One of the biggest indicators to me that this is going to capitalize on its environment well is the dual outflow channels that seem to be starting to set up. I think DMAX is going to be productive this evening, and I may be bold, but I am thinking we will have a major by tomorrow morning.

I’m surprised we are still leaning on DMAX for intensity help and it seems nobody can agree where the center is. I’m really surprised.

[cfisher]

There's a hot tower on top of the core now.

[wx98]

NOAA plane has taken off from Florida, should arrive at Laura within the hour.

Not sure about the AF plane. The departure time was listed as 2030z. It is now 2130z...

[Blown Away]

One of the biggest indicators to me that this is going to capitalize on its environment well is the dual outflow channels that seem to be starting to set up. I think DMAX is going to be productive this evening, and I may be bold, but I am thinking we will have a major by tomorrow morning.

I’m surprised we are still leaning on DMAX for intensity help and it seems nobody can agree where the center is. I’m really surprised.

24.7N/88.3W at 4pm, so a bit WNW from there is the COC, not much argument I don’t think.

[AxaltaRacing24]

There's a hot tower on top of the core now.

yeah. tons of hot towers right over the center heading into dmin...

[FLpanhandle91]

Recon is on the way out of Tampa Bay.

[AxaltaRacing24]

One of the biggest indicators to me that this is going to capitalize on its environment well is the dual outflow channels that seem to be starting to set up. I think DMAX is going to be productive this evening, and I may be bold, but I am thinking we will have a major by tomorrow morning.

I’m surprised we are still leaning on DMAX for intensity help and it seems nobody can agree where the center is. I’m really surprised.

dmax helps every storm. look at irma in 2017. category 3 heading into dmin, and was a cat 5 after dmax ended.

[eastcoastFL]

[cheezyWXguy]

One of the biggest indicators to me that this is going to capitalize on its environment well is the dual outflow channels that seem to be starting to set up. I think DMAX is going to be productive this evening, and I may be bold, but I am thinking we will have a major by tomorrow morning.

I’m surprised we are still leaning on DMAX for intensity help and it seems nobody can agree where the center is. I’m really surprised.

DMAX seems to play a role as long as there’s a bursting pattern, until a consolidated ring has formed, at least from what I’ve seen. I don’t think DMIN/DMAX will be a factor tomorrow

[Steve]

I think they are getting pretty confident about the strength, Conditions are Good for strengthening, just not perfect, which is why they are probably leveling it off at 115 mph

They’ll be fairly close to excellent. But with only 30something hours until landfall, it’s not going to have enough time to drop super low. There are some historical exceptions. I believe someone brought up Wilma yesterday. But even if it drops say another 40mb by landfall, that’s still impressive af.

Climatologically, a 40mb drop over 36 hours with the environment, core structure and SSTs seems low.

Sorry if I wasn't clear. I was using 40mb just as a low-range random qualifier.

Just the same, if you're starting out from 990 and very loose organization, being able to get to a Cat 3 in a day and a half is still a feat. If you consider that most years only have about 2.5 majors, they are already rare events. Some of them intensify in a series of multiple bursts. Some take a few eyewall replacement cycles to achieve that kind of maturity. Some can nosedive in pressure based on surrounding pressure patterns. Laura has a straight shot to the coast with minor impediments but only 31 or so hours left. 40mb would bring her to 950. 50 takes her to 940. 60mb to 930. I don't /think/ she gets all the way to 930, but had she not been interrupted on the way through the islands, I think an argument for near Cat 5 conditions could be made.

[syfr]

Amazing that after scrubbing itself across half of North America, NHC shows her still reforming into a extra/post TS off of Cape Cod!

[NotoSans]

This is a typical intensification pattern observed in WPAC storms - a large banding eye starts to form, then becomes obscure due to convective burst. Given current satellite presentation, I expect recon to find a 75-80kt hurricane.

[AnnularCane]

Amazing that after scrubbing itself across half of North America, NHC shows her still reforming into a TS off of Cape Cod!

It actually shows her being post-tropical/extratropical by then.