EPAC: BONNIE - Post-Tropical - Discussion

[Teban54]

I wanted to make this post after PTC2 is all done on the Atlantic side, but looks like folks are getting impatient lol.

While it's easy to think of PTC2 as underachieving or even a bust, IMO its biggest limiting factor wasn't unfavorable conditions; it was steering and geography. Most ensemble members and operational runs of all models last week consistently showed the strongest solutions further north and weaker solutions further south, and ensemble members that sent the system into NW Caribbean and the Gulf mostly made it a solid hurricane. To me, this suggests that if the ridge was weaker and PTC2 took a more northerly track (between its actual path and Elsa's path), its potential would have been a lot higher with less interference from South America.

[Ubuntwo]

I wanted to make this post after PTC2 is all done on the Atlantic side, but looks like folks are getting impatient lol.

While it's easy to think of PTC2 as underachieving or even a bust, IMO its biggest limiting factor wasn't unfavorable conditions; it was steering and geography. Most ensemble members and operational runs of all models last week consistently showed the strongest solutions further north and weaker solutions further south, and ensemble members that sent the system into NW Caribbean and the Gulf mostly made it a solid hurricane. To me, this suggests that if the ridge was weaker and PTC2 took a more northerly track (between its actual path and Elsa's path), its potential would have been a lot higher with less interference from South America.

Forward speed from intense ridging has also contributed to its struggles in forming an LLC. Since 18z on 6/27, the Euro and ICON have depicted this accurately, with a closed circulation developing @ 80W. The GFS and models sharing its initialization (HWRF) held out far longer in a lower forward speed leading to more developed system.

[aspen]

Ironically recon indicates there's no longer a closed circulation like there was earlier.

Go figure. Bonnie is gonna have to wait until mid August at this rate.

It’s incredible how both PTCs this year waited until they had 24 hours or less left to develop. Alex lasted for only a day, and Bonnie will spend like 18 hours at most in the Atlantic, despite being around for longer and having the opportunity to develop days ago. Slightly weaker ridging would’ve turned this into an Elsa ‘21 or Cesar ‘96.

[Category5Kaiju]

Ngl, a small part of me is still rooting for this to become Bonnie because I think it'd be pretty cool and wack to see a Hurricane Bonnie in the Eastern Pacific haha. Fingers crossed until the inevitable CA landfall in the time being!

[cheezyWXguy]

Amazed this still hasn’t consolidated enough to be classified. It’s been a wild ride watching this thing try

[Teban54]

Imagine after 22+ pages of discussions, this thread ends up being archived in S2K as Hurricane Darby

[Category5Kaiju]

Imagine after 22+ pages of discussions, this thread ends up being archived in S2K as Hurricane Darby

That would be really funny….or better yet, if for some reason this PTC still carried its vendetta against ever forming, so it enters the EPAC and still does not form into a NS there

[FireRat]

Imagine after 22+ pages of discussions, this thread ends up being archived in S2K as Hurricane Darby

That would be really funny….or better yet, if for some reason this PTC still carried its vendetta against ever forming, so it enters the EPAC and still does not form into a NS there

Hahaha and sadly this may even have a real chance! Might as well continue into the EPac as PTC.
2022 the year of the PTC it seems

[Hammy]

Looks like it's probably a tropical storm but might be inland in the next 6-8 hours at the speed it's moving

[al78]

This is what this PTC reminds me of:

https://www.youtube.com/watch?v=hNYWcVq_h8g

I have to say I was a bit surprised at the repeated forecasts to develop into a minimal hurricane. I would have thought its proximity to the South American coastline would have been an inhibiting factor.

[kevin]

Waiting for PTC2 to become Bonnie:

[ElectricStorm]

Finally starting to look like a TS, at least on IR, but it seems to me like it's not slowing down. We'll see if it finally has a true LLC when recon gets there but by that time it might be pretty close to land at this rate. Gonna be a close call on whether this finally gets named or not.

[USTropics]

PTC2 is exhibiting characteristics of a legit tropical cyclone this morning, with an increase in convection with DMAX. The topography of Central America has likely assisted in the closing off of westerly/SW flow, similar to what we see in the BOC:



Early morning visible imagery + recon should confirm what's taking place, but clear banding features are occurring:


Easterlies are also not as prevalent the closer to CA the system gets, which will result in some slow down in speed today. Should still make landfall this evening (~10PM ET - 2AM ET).

[wxman57]

I think it'll be reclassified as "Bonnie" shortly.

[aspen]

Recon is almost there. Last chance to become Bonnie.

Who would’ve guessed this would waste 95% of its existence in the Atlantic and only try to develop until its last 6-12 hours before landfall? I was going to compliment the Euro for sniffing out development before any other model, but even it was too aggressive with too weak ridging. How the heck does the Euro of all models under-estimate ridging?

[WiscoWx02]

Recon is almost there. Last chance to become Bonnie.

Who would’ve guessed this would waste 95% of its existence in the Atlantic and only try to develop until its last 6-12 hours before landfall? I was going to compliment the Euro for sniffing out development before any other model, but even it was too aggressive with too weak ridging. How the heck does the Euro of all models under-estimate ridging?

Hopefully the models can resolve this issue by the peak of the hurricane season or this season is going to be tricky. Might have to rely on the look out the window method more than the models this year Granted the models are still useful for overall background state to some extent…they got the weirdly favorable upper level environment, they just failed to acknowledge that it is still late June now early July and trades are ripping through the Caribbean Sea regardless

[WiscoWx02]

Convective towers are definitely wrapping around what I really just wanna call a center but who knows at this point

[aspen]

Recon is almost there. Last chance to become Bonnie.

Who would’ve guessed this would waste 95% of its existence in the Atlantic and only try to develop until its last 6-12 hours before landfall? I was going to compliment the Euro for sniffing out development before any other model, but even it was too aggressive with too weak ridging. How the heck does the Euro of all models under-estimate ridging?

Hopefully the models can resolve this issue by the peak of the hurricane season or this season is going to be tricky. Might have to rely on the look out the window method more than the models this year Granted the models are still useful for overall background state to some extent…they got the weirdly favorable upper level environment, they just failed to acknowledge that it is still late June now early July and trades are ripping through the Caribbean Sea regardless

Trades weren’t the main problem, it was the fact that PTC2 went on the southernmost side of the model guidance that didn’t have it dying over SA. If it was any further north, we could’ve had TS Bonnie as early as Tuesday. They did do poorly with trades and forward speed, sure, but PTC2’s latitude was the biggest hindrance and the models’ biggest blunder.

Also is recon turning back, or are they doing a circle as they descend?
EDIT: just circling down to operational altitude. The moment of truth is less than an hour away.

[tolakram]

I don't see any model issues that are unusual for June and early July in my amateur opinion. The HWRF has never been wrong about developing a system except for all the times it's been wrong about developing a system.

I'm still not convinced there's an LLC, all I see are westward moving lower clouds, but I suppose one could be in there somewhere.

COD floater: https://weather.cod.edu/satrad/?parms=m ... =undefined

[USTropics]

Clear hot towers rotating in early visible imagery:


Recon is closing in: