ATL: LARRY - Post-Tropical - Discussion

[Sciencerocks]

[Landy]

90kt peak.

 https://twitter.com/NHC_Atlantic/status/1432803896829771780

[aspen]

Another very aggressive first NHC forecast cone — a hurricane in 60 hours and 90 kt by 5 days. We’ll likely be looking at major Hurricane Larry in a few days at this rate.

[Woofde]

Wow, potential to be the 3rd Major of the season and we aren't even half way through the season. Hopefully this one breaks the trend of the hurricanes affecting land this year.

[AutoPenalti]

The initial motion is a somewhat uncertain 285/14. A strong low-
to mid-level ridge to the north should cause the cyclone to move
westward at a faster forward speed for the next 36 h or so,
followed by a gradual turn toward the west-northwest and northwest
by the end of the period as the depression moves along the
southwest side of the ridge. There is some spread in the guidance
after 36-48 h, with the GFS and GFS ensemble mean showing a more
northward motion while the UKMET and the UKMET ensemble mean show a
more westward motion. The official forecast is near the middle of
the guidance envelope and is close to the HFIP corrected consensus
model, which is a little to the south of the other consensus models.

[supercane4867]

HWRF thinks future Hurricane Larry has a good chance of becoming annular. Not an unreasonable outcome given the conditions ahead

[Teban54]

Another very aggressive first NHC forecast cone — a hurricane in 60 hours and 90 kt by 5 days. We’ll likely be looking at major Hurricane Larry in a few days at this rate.

Wasn't pre-Ida' 95kt forecast on the first advisory a record for the highest initial forecast intensity? And now we have another advisory #1 with an intensity just 5 kts lower...

Hope this stays away from all land masses including Bermuda, or else someone will be in trouble.

[kevin]

Another very aggressive first NHC forecast cone — a hurricane in 60 hours and 90 kt by 5 days. We’ll likely be looking at major Hurricane Larry in a few days at this rate.

Wasn't pre-Ida' 95kt forecast on the first advisory a record for the highest initial forecast intensity? And now we have another advisory #1 with an intensity just 5 kts lower...

Hope this stays away from all land masses including Bermuda, or else someone will be in trouble.

Yep, Ida and Iota are the only 95 kt forecasts to date. It's seems to be some sort of unwritten rule never to put the M in the first forecast so 95 kt is the maximum. So the NHC going with 90 kt combined with their hurricane forecast in 60 hours clearly indicates that they're also quite bullish on the system. And I mean, why not, literally every model is big on development for this system. Hopefully it'll remain OTS, I'm not liking these small but consistent SW changes every model cycle.

[abajan]

Interesting excerpt from the NHC Forecast Disco:

Conditions appear favorable for intensification during the next 72 h or so as the cyclone is in a moist environment with light shear and warm sea surface temperatures. The intensity forecast thus calls for the cyclone to become a tropical storm in 12 h or so and reach hurricane strength in 48-60 h. By the end of the forecast period, the forecast track takes the cyclone over slightly cooler water and into a drier air mass. Based on this, the intensity forecast calls for a slower development rate. The official intensity forecast is in the middle of the intensity guidance, and it is possibly conservative given that many of the global models are showing the development of a large and powerful tropical cyclone.

[cycloneye]

 https://twitter.com/webberweather/status/1432812510130933760

[Category5Kaiju]

https://twitter.com/webberweather/status/1432812510130933760

Probably because of the projected annularity and the track, but for some reason future Larry gives me vibes of Isabel.

[ElectricStorm]

I'm wondering if a weaker Kate is the reason for these SW shifts on the models. A couple days ago the Euro showed this moving a little more SW than the others, and it also showed a weaker Kate than the other. I think that there's a good chance this recurves, but I'm not 100% confident in that and this will need to be watched for more west shifts imo.

[ThetaE]

Another very aggressive first NHC forecast cone — a hurricane in 60 hours and 90 kt by 5 days. We’ll likely be looking at major Hurricane Larry in a few days at this rate.

Wasn't pre-Ida' 95kt forecast on the first advisory a record for the highest initial forecast intensity? And now we have another advisory #1 with an intensity just 5 kts lower...

Hope this stays away from all land masses including Bermuda, or else someone will be in trouble.

Yep, Ida and Iota are the only 95 kt forecasts to date. It's seems to be some sort of unwritten rule never to put the M in the first forecast so 95 kt is the maximum. So the NHC going with 90 kt combined with their hurricane forecast in 60 hours clearly indicates that they're also quite bullish on the system. And I mean, why not, literally every model is big on development for this system. Hopefully it'll remain OTS, I'm not liking these small but consistent SW changes every model cycle.

I think the NHC is just getting more confident/better at determining storms that may quickly or rapidly intensify down the road. It's not like these sort of favorable scenarios for quick ramp-ups didn't happen historically, but prediction skills are definitely a lot better nowadays.

[Blown Away]

https://twitter.com/webberweather/status/1432812510130933760

Has an Annular Hurricane ever made a landfall in the Atlantic Basin??

[kevin]

Wasn't pre-Ida' 95kt forecast on the first advisory a record for the highest initial forecast intensity? And now we have another advisory #1 with an intensity just 5 kts lower...

Hope this stays away from all land masses including Bermuda, or else someone will be in trouble.

Yep, Ida and Iota are the only 95 kt forecasts to date. It's seems to be some sort of unwritten rule never to put the M in the first forecast so 95 kt is the maximum. So the NHC going with 90 kt combined with their hurricane forecast in 60 hours clearly indicates that they're also quite bullish on the system. And I mean, why not, literally every model is big on development for this system. Hopefully it'll remain OTS, I'm not liking these small but consistent SW changes every model cycle.

I think the NHC is just getting more confident/better at determining storms that may quickly or rapidly intensify down the road. It's not like these sort of favorable scenarios for quick ramp-ups didn't happen historically, but prediction skills are definitely a lot better nowadays.

I did some more research and it turns out that there have actually been 3 more 95 kt first advisories. Here's an overview of all 80+ kt first advisories since the modern advisories started (or at least as far as they have been archived on the NHC website) since 1998. A big sidenote is that up until and including 2002 they only did 72hr advisories instead of 120hr. The lowest first advisory ever given to a system that eventually became a MH was to Joaquin in 2015, which was forecast to peak as a 30 kt TD.

Edit: in my initial post I excluded cat 1's due to the time constraint, but I just checked those as well and I found 3 more 95+ kt cases. 2012 Isaac and 2005 Philippe were also forecast at 95 kt. And even crazier, in 2010 Tomas was given the 100 kt forecast. That forecast busted with Tomas 'only' becoming a cat 2 so perhaps that's why they've been reluctant with giving a storm the big M on its first forecast.

100 kt
2010 - Tomas

95 kt
2021 - Ida
2020 - Iota
2019 - Lorenzo
2012 - Isaac
2010 - Danielle
2005 - Philippe
2004 - Karl

90 kt
2021 - TD12
2017 - Jose
2016 - Matthew
2009 - Bill
2007 - Dean

85 kt
2020 - Delta
2015 - Danny
2014 - Gonzalo
2011 - Katia
2010 - Earl
2010 - Igor
2005 - Wilma

80 kt
2020 - Teddy
2019 - Jerry
2017 - Maria
2016 - Gaston
2012 - Leslie
2005 - Rita

[Category5Kaiju]

https://twitter.com/webberweather/status/1432812510130933760

Has an Annular Hurricane ever made a landfall in the Atlantic Basin??

Yes, Hurricane Irma when it struck Barbuda and Antigua is a great example. Perfectly circular and fierce like a tire of death with 180 mph ripping winds.

[hipshot]

From Spongebob to Veggie Tales to the 3 Stooges, a Cat 4 Larry sure will unleash a storm of memes on social media.

Only if you encourage it!!

[cheezyWXguy]

https://twitter.com/webberweather/status/1432812510130933760

Has an Annular Hurricane ever made a landfall in the Atlantic Basin??

Yes, Hurricane Irma when it struck Barbuda and Antigua is a great example. Perfectly circular and fierce like a tire of death with 180 mph ripping winds.

Yeah, that’s probably the closest example. It did display some annular characteristics although I don’t think it’s technically classified as annular.

[Zonacane]

https://twitter.com/webberweather/status/1432812510130933760

Has an Annular Hurricane ever made a landfall in the Atlantic Basin??

Isabel

[Ubuntwo]

https://twitter.com/webberweather/status/1432812510130933760

Has an Annular Hurricane ever made a landfall in the Atlantic Basin??

Yes, Hurricane Irma when it struck Barbuda and Antigua is a great example. Perfectly circular and fierce like a tire of death with 180 mph ripping winds.

Hurricane Irma was a compact buzzsaw with some annular characteristics, but not a proper annular cane. Because of the SST profile required for annularization(?), it doesn't look like any Atlantic hurricane has made landfall while still annular.