ATL: ERNESTO - Post-Tropical - Discussion

[JRD]

Looking like a mix of Epsilon 2020 and the increasingly comma-like pattern of an ETing cyclone.

[JRD]

Ernesto now has an embedded trough axis, meaning its extratropical transition is further underway.

[aspen]

Looking better this morning, but it’s clear that Ernesto won’t be reaching MH intensity. I knew something was up when the HWRF was consistently yielding a structure that would prohibit significant intensification. It must’ve been picking up on the factors that ended up plaguing Ernesto: its large circulation size and the presence of dry air. Together they prevented a small, compact core ripe for RI in both the model runs and in reality.

[MEANINGLESS_NUMBERS]

Bermuda recovery is well underway. No significant injuries. No significant damage. All road have reopened despite some impressive trees coming down. 35% of customers without power (down from 75%). We are one of those houses technically without power but with solar+batteries are quite comfortable. As long as this fair weather holds we can stay off the grid indefinitely.

[Ubuntwo]

Looking better this morning, but it’s clear that Ernesto won’t be reaching MH intensity. I knew something was up when the HWRF was consistently yielding a structure that would prohibit significant intensification. It must’ve been picking up on the factors that ended up plaguing Ernesto: its large circulation size and the presence of dry air. Together they prevented a small, compact core ripe for RI in both the model runs and in reality.

They didn’t project RI per se, but all hurricane models portrayed a major hurricane for many cycles each. Ernesto’s structure was definitely capable of supporting a cat 3 given 107 kts at 700mb and ~120kt instantaneous winds in the boundary layer. Dry air was the biggest inhibitor in that it prevented convection from being continuous enough to allow these winds to mix down to sfc. Recon missed the clear eye by several hours, so I think it still could’ve reached the 90-95kt range. You’re right in that its huge fetch probably rendered it more vulnerable to the continuous dry air intrusions.

[Ubuntwo]

Ernesto now has an embedded trough axis, meaning its extratropical transition is further underway.

Ernesto is doing a couple things, but transitioning doesn’t appear to be one of them. Most tropical its looked in a while now that trough #1 has moved out.

[galaxy401]

NHC doesn't forecast it to become ET for another 48 hours so the transition shouldn't start just yet. Ernesto is probably a hurricane again.

[weeniepatrol]

This is a tropical cyclone.

[aspen]

I’m surprised the NHC didn’t upgrade Ernesto back to a Cat 1 at 11am, but if it keeps this up, it should be at least 70 kt by 5pm.

[hipshot]

I’m surprised the NHC didn’t upgrade Ernesto back to a Cat 1 at 11am, but if it keeps this up, it should be at least 70 kt by 5pm.

Where is it headed?

[cycloneye]

Hurricane at 5 PM.

AL, 05, 2024081818, , BEST, 0, 364N, 627W, 65, 977, HU

[aspen]

I’m surprised the NHC didn’t upgrade Ernesto back to a Cat 1 at 11am, but if it keeps this up, it should be at least 70 kt by 5pm.

Where is it headed?

Looks like it’ll miss Atlantic Canada and get shot out into the North Atlantic as a post-tropical low.

[WaveBreaking]

[weeniepatrol]

https://www.ospo.noaa.gov/tropical-data ... 0005L.html

A. 05L (ERNESTO)

B. 18/1800Z

C. 36.4N

D. 62.7W

E. THREE/GOES-E

F. T2.5/2.5

G. IR/EIR/VIS

H. REMARKS...7/10 BANDING RESULTS IN A DT OF 3.0. THE MET IS 2.5 DUE
TO A STEADY 24 HOUR TREND. THE PT AGREES. THE FT IS BASED ON THE MET
DUE TO THE FLUCTUATING CONVECTION.

You heard it here first, folks!

[Sciencerocks]

[Hurricane2022]

Making a run for Cat 2 again?

I think so, but DISASTROUS estimates like these will definitely influence the NHC at least a little and make them less confident to do such an upgrade

https://www.ospo.noaa.gov/tropical-data/2024/bulletins/natl/20240818180005L.html

A. 05L (ERNESTO)

B. 18/1800Z

C. 36.4N

D. 62.7W

E. THREE/GOES-E

F. T2.5/2.5

G. IR/EIR/VIS

H. REMARKS...7/10 BANDING RESULTS IN A DT OF 3.0. THE MET IS 2.5 DUE
TO A STEADY 24 HOUR TREND. THE PT AGREES. THE FT IS BASED ON THE MET
DUE TO THE FLUCTUATING CONVECTION.

You heard it here first, folks!

[Sciencerocks]

75 knts in my opinion and could be 85 knts by 11pm at this rate.

I wouldn't be shocked to see 90 knts+ before it weakens.

[aspen]

https://www.ospo.noaa.gov/tropical-data/2024/bulletins/natl/20240818180005L.html

A. 05L (ERNESTO)

B. 18/1800Z

C. 36.4N

D. 62.7W

E. THREE/GOES-E

F. T2.5/2.5

G. IR/EIR/VIS

H. REMARKS...7/10 BANDING RESULTS IN A DT OF 3.0. THE MET IS 2.5 DUE
TO A STEADY 24 HOUR TREND. THE PT AGREES. THE FT IS BASED ON THE MET
DUE TO THE FLUCTUATING CONVECTION.

You heard it here first, folks!

Add that to the list of the worst manual Dvorak fixes of all time. Hopefully the NHC throws this out for the 5pm advisory, although I’m not sure the ADT estimates will be any better.

[cycloneye]

A few more ACE units.

INIT 18/2100Z 37.1N 62.3W 65 KT 75 MPH
12H 19/0600Z 39.2N 60.9W 75 KT 85 MPH
24H 19/1800Z 42.6N 57.1W 70 KT 80 MPH
36H 20/0600Z 46.1N 50.7W 55 KT 65 MPH

[weeniepatrol]

from the 5pm discussion

The structure of Ernesto this afternoon has continued to improve,
with a more distinct eye becoming apparent on recent visible and
infrared satellite images. This improving inner-core structure is
also exhibited in a 1808 UTC GMI microwave pass that also showed a
closed cyan ring on the 37-GHz color composite channel, which could
be a harbinger for more significant intensification.

I wholeheartedly believe the assessed intensity of 65 kt is ~15-20 kt too low