ATL: FIONA - Post-Tropical - Discussion

[Meteophile]

I had a doubt about the real impact of land interaction. Cloudtops around the eyewall didn't seem to have the same speed (much slower on the southwestern part), maybe the storm didn't really have a solid stable eyewall all this time, which may be why it looks like the structure is evolving in a way it doesn't look that good on IR (despite some deepening) ?

[Iceresistance]

I had a doubt about the real impact of land interaction. Cloudtops around the eyewall didn't seem to have the same speed (much slower on the southwestern part), maybe the storm didn't really have a solid stable eyewall all this time, which may be why it looks like the structure is evolving in a way it doesn't look that good on IR (despite some deepening) ?

I've recently looped it and it could be overshooting tops by the intense western eyewall convection that are obscuring the eye, there is still a lot of lightning in the eyewall.

[Iceresistance]

NOAA2 is inside Fiona, the pressure gradient is tight! Already down to 988.3 mb Extrapolated and it's not even at the eyewall yet.

[Iceresistance]

Not finding Cat 3 Hurricane status on the first pass, but the pressure is lower, lowest is 958.3 mb extrapolated.

EDIT: Never mind, the SMFR is 100 knots unflagged

[aspen]

I don’t think this is a major anymore. Recon has just arrived and will find out what’s going on, whether it be shear or an EWRC.

That aged poorly. Extrapolated pressure is 8mb lower than the 5am advisory, and there are still Cat 3 winds in the NE quad.

[kevin]

Goes to show that IR on its own doesn't tell you everything.

10 hours ago, 974 mb & 90 kt according to NHC


Now, 958 mb & 99 kt according to recon

[Iceresistance]

The eye of Fiona must be really close to a pinhole.

Recon has an eye dropsonde that has 962 mb and 50 knots of wind.

[aspen]

The eye of Fiona must be really close to a pinhole.

Recon has an eye dropsonde that has 962 mb and 50 knots of wind.

Probably an EWRC messing with things. There seems to be an actual double wind maxima in the NE quad, but it doesn’t look to be a very big other eyewall.

[Iceresistance]

Next pass has higher pressure, 959.9 mb extrapolated.

SMFR is 95 knots now, she has weakened, which is likely from a EWRC

[Iceresistance]

I believe that we have a satellite outage right now. No data coming in since 11z (Currently 1247z)

[kevin]

You can clearly see the detereoration of the inner eyewall and in the last frames the new larger eyewall so indeed it seems we had an EWRC.

[aspen]

You can clearly see the detereoration of the inner eyewall and in the last frames the new larger eyewall so indeed it seems we had an EWRC.

https://imgur.com/RRyVj6Z

Now the question is if Fiona will be able to recover and strengthen again in the short amount of time before it starts to recurve. I get the feeling that everyone is expecting another Earl situation as soon as Fiona begins interacting with that trough.

Also is it just me, or is Fiona going a little W of forecast again?

[kevin]

The latest passes indicate some slight weakening due to the EWRC. 961.6 mb with 94 kt FL winds could support ~90 kt if you take into account undersampling due to Fiona's difficult-to-navigate structure atm. Not sure if NHC will weaken it in the upcoming forecast though since 1) it's close to land and 2) it's expected to resume strengthening soon. Might be something they'll look into in the post-season analysis.

[cheezyWXguy]

This ERC is is going pretty fast. Already starting to see the western portions of the cloud filled larger eye on visible.

[kevin]

Looks like Fiona has stopped weakening or even started strenghtening again a little bit: latest pass found a pressure of 961.4 mb and FL winds of 100 kt. This is in accordance with IR/VIS where you can indeed see that the EWRC has quickly been completed.

Also ignore the 162 kt SFMR from the data set afterwards, those measurements are from above land.

[kevin]

The eye is now warming up on IR, even though it's a bit difficult to see due to cloudtops in the strengthening new eyewall. Now that the EWRC is done Fiona's Dvorak estimate is also much closer to the real intensity: current raw T# is 5.3 (964 mb, 97 kt). Hopefully this means that we can use ADT as a more reliable estimate again in between recon flights. Before it was less accurate due to the landfalls and afterwards due to the EWRC.

[toad strangler]

ACE fiends may get their fix these next couple weeks.

[aspen]

Wow, unflagged and totally 100% reliable ~160 kt SFMR readings. I guess we have a Cat 5 now!

[Sciencerocks]

[HurricaneBelle]

Grand Turk getting hammered right now.