ATL: ELSA - Post-Tropical - Discussion

[captainbarbossa19]

Remember Gonzalo last year? Models (and NHC) forecasting it to cross in the Caribbean as a hurricane, but it dissipated as it reached the islands. A model forecast of a strong storm by the GFS is no guarantee it will be a strong storm. No guarantee it will survive the strong easterly tradewinds in the eastern Caribbean.

Hopefully this will be more like Gonzalo and less like Dennis.

[SFLcane]

Here we go!

 https://twitter.com/nhc_atlantic/status/1410331333096665092

[aspen]

The NHC is, for some reason, going with PTC-5 instead of a TC. We’ll have to wait until post-season analysis for a June 30th upgrade, apparently.

[InfernoFlameCat]

Remember Gonzalo last year? Models (and NHC) forecasting it to cross in the Caribbean as a hurricane, but it dissipated as it reached the islands. A model forecast of a strong storm by the GFS is no guarantee it will be a strong storm. No guarantee it will survive the strong easterly tradewinds in the eastern Caribbean.

What did HWRF say about Gonzalo (2020)?

I'm fairly sure it strengthened it into a hurricane in the eastern Caribbean. Somehow, I lost my folder of 2020 data, including the HWRF plots, though.

Slightly unrelated topic but did you badmouth Harvey? It came straight for you after dying in the Caribbean. Don’t make Elsa mad

[Iceresistance]

Here we go!!!

 https://twitter.com/nhc_atlantic/status/1410331333096665092

How much did 2020 have up until June 30th?

[InfernoFlameCat]

The NHC is, for some reason, going with PTC-5 instead of a TC. We’ll have to wait until post-season analysis for a June 30th upgrade, apparently.

Wait because EDT still is in June right? Unless they don’t upgrade then

[captainbarbossa19]

The NHC is, for some reason, going with PTC-5 instead of a TC. We’ll have to wait until post-season analysis for a June 30th upgrade, apparently.

Honestly, I thought that they might call it a depression. It seems like most think that this has enough organization to be upgraded to at least that.

[ElectricStorm]

The NHC is, for some reason, going with PTC-5 instead of a TC. We’ll have to wait until post-season analysis for a June 30th upgrade, apparently.

Wait because EDT still is in June right? Unless they don’t upgrade then

7 pm CDT (8pm EDT) is 0z, so unless they upgrade at the next advisory, then it will be a July named storm

[AutoPenalti]

Remember Gonzalo last year? Models (and NHC) forecasting it to cross in the Caribbean as a hurricane, but it dissipated as it reached the islands. A model forecast of a strong storm by the GFS is no guarantee it will be a strong storm. No guarantee it will survive the strong easterly tradewinds in the eastern Caribbean.

What did HWRF say about Gonzalo (2020)?

I'm fairly sure it strengthened it into a hurricane in the eastern Caribbean. Somehow, I lost my folder of 2020 data, including the HWRF plots, though.

viewtopic.php?f=90&t=121022&start=20

GFS-P won that model war. Dry air and shear prevented any sort of intensification with Gonzalo.

[InfernoFlameCat]

On a broader note, if 2021 usurps 2020 in named storms…
Elsa started it so blame her.

[Sciencerocks]

[Aric Dunn]

The way the convection is popping now.. by 11pm I don't think they will have much choice. even if they don't get a good ASCAT pass.

[AlphaToOmega]

Remember Gonzalo last year? Models (and NHC) forecasting it to cross in the Caribbean as a hurricane, but it dissipated as it reached the islands. A model forecast of a strong storm by the GFS is no guarantee it will be a strong storm. No guarantee it will survive the strong easterly tradewinds in the eastern Caribbean.

What did HWRF say about Gonzalo (2020)?

I'm fairly sure it strengthened it into a hurricane in the eastern Caribbean. Somehow, I lost my folder of 2020 data, including the HWRF plots, though.

I found the strongest HWRF model run for Gonzalo (2020) I could find here. It was a 965 mb hurricane with maximum wind speeds of 102 knots. I would translate that to ~90 knots. The latest HWRF run has this intensifying to 954 mb with maximum wind speeds of 137 knots. I would translate that to ~120 knots. Clearly, HWRF is much more bullish with this system than with Gonzalo (2020).

[AJC3]

The NHC is, for some reason, going with PTC-5 instead of a TC. We’ll have to wait until post-season analysis for a June 30th upgrade, apparently.

As I'm sure you'll see them mention in the TCD, the system has lacked a well-defined, closed LLCC. This is readily apparent in the several scatterometer passes that have been posted today - in particular the METOP-C pass from 1247Z. Is it possible that the center has closed off since then? Perhaps. However it's fast forward speed may still be keeping this an open wave. To start speculating about a post season upgrade, before the initial advisory has even been sent, is quite premature. If there's no solid evidence that the system has become closed off/well defined, then any speculative post-season upgrade likely isn't going to change that (in absence of say, a late-arriving ship report).

If they don't decide to call it a TC at 5 or 11 PM, then there's a strong likelhood that it won't be post-analyzed as such either.

[Nuno]

What did HWRF say about Gonzalo (2020)?

I'm fairly sure it strengthened it into a hurricane in the eastern Caribbean. Somehow, I lost my folder of 2020 data, including the HWRF plots, though.

I found the strongest HWRF model run for Gonzalo (2020) I could find here. It was a 965 mb hurricane with maximum wind speeds of 102 knots. I would translate that to ~90 knots. The latest HWRF run has this intensifying to 954 mb with maximum wind speeds of 137 knots. I would translate that to ~120 knots. Clearly, HWRF is much more bullish with this system than with Gonzalo (2020).

Also, proto-Elsa will face much less shear than Gonzalo.

[Stormybajan]

https://imagizer.imageshack.com/img923/3597/KQb5ft.gif

This is definitely the most impressive june MDR system I can remember...I expect tropical storm watches to be placed for Dominica all the way down to Grenada..the water only gets warmer from here and the OHC also increases as it goes along. PTC5 has really taken advantage of the path 95L gave it

[presidentofyes12]

Here's a simulated IR satellite forecast from the HWRF model. It's wind speeds here are about 128 mph.

[eastcoastFL]

https://pipe.miroware.io/5ea73c85ba35b8055638eb96/hwrf_satIR_97L_21.png
Here's a simulated IR satellite forecast from the HWRF model. It's wind speeds here are about 128 mph.

It’s usually pretty close with it’s prediction of IR presentation. But that will depend on land interaction down the line. I am interested in what it depicts for the next 24-48 hours because that should be pretty accurate

[Iceresistance]

https://pipe.miroware.io/5ea73c85ba35b8055638eb96/hwrf_satIR_97L_21.png
Here's a simulated IR satellite forecast from the HWRF model. It's wind speeds here are about 128 mph.

Oh my, that is close to how strong Dennis was in 2005!

[StPeteMike]

While on the side discussion of Gonzalo, models also had very less data from airplanes last year than now. That data would had probably helped all the models to show that the environment in the Eastern Caribbean wouldn’t be able to provide favorable conditions for such a little storm.

Future Elsa doesn’t have that issue. More data from international flights for these models to incorporate into their models. And, as mentioned, much larger storm and has 95L to clear the SAL out and provide better conditions than Gonzalo clearly had.