ATL: FIONA - Post-Tropical - Discussion

[chaser1]

I'm still a bit foggy-eyed this a.m. but my first impression is that Fiona is slowing down and that a new LLC within the whole convective mass will soon become evident. Outflow certainly appears to have improved. My concern for hurricane force conditions for Puerto Rico just jumped a few notches.

[NDG]

Curious that none of the northern Lesser Antilles reported any sustained wind over 30 kts overnight. Guadeloupe (TFFF) reported 30kts gusting 50kts at 06Z, but 20 kts or less after that report. You can use the link below and go back to yesterday, or you can type in a stations 4-letter ICAO and check the obs over the past 24 hrs or more.

https://aviationweather.gov/metar

Well I would think St John's Island to the north of Guadeloupe probably had higher sustained winds but they stopped reporting after 9 PM.

[NDG]

Convection re-firing near where the AF recon fixed the CoC.

[Blown Away]

The blob hasn’t moved much in past few hours.

NHC 5am 16.3/64.3 moving W at 13 and 8am was 16.1/64.4. If you factor Fiona should have moved @39 miles W since 5am and the S adjustment, that is a near @50 mile adjustment to the ESE.

[wxman57]

Recon indicates Fiona's winds are closer to 40 kts than 50 kts. Lack of any TS winds across the Antilles as Fiona passed supports 40 kts or less.

[skyline385]

Then comes the AF recon and fixes a center further north, the nice LLC it had last night fell apart, but it still has a closed circulation, but broad with multiple centers.

https://i.imgur.com/HqEVDz1.png

AF is flying at ~850 mb, NOAA2 is flying at ~700 mb, appears from recon that at least one of the 700 mb centers is about a degree latitude south of the 850 mb center AF just found at ~16.1 degrees N.

Evidence that this is still a significantly tilted system, which is also likely the reason why recon hasn't found anything overly impressive, despite all the convection currently.

The AF drop at the fix also probably supports this, winds go from 3 kts at FL to 28 kts at surface

[NDG]

[url]https://i.postimg.cc/g2457bC0/goes16-vis-07-L-202209171015.gif [/url]

The blob hasn’t moved much in past few hours.

NHC 5am 16.3/64.3 moving W at 13 and 8am was 16.1/64.4. If you factor Fiona should have moved @39 miles W since 5am and the S adjustment, that is a near @50 mile adjustment to the ESE.

Which means the track will inch closer to PR as the day goes by.

[InfernoFlameCat]

Looking at visible, there appears to be no low level center at the moment. The clouds are at a standstill on the west of the supposed center.

[NDG]

Recon indicates Fiona's winds are closer to 40 kts than 50 kts. Lack of any TS winds across the Antilles as Fiona passed supports 40 kts or less.

Yeah, definitely not a 50 knot storm.
Unflagged strongest winds so far in red:

54 knots
(~ 62.1 mph) 43 knots
(~ 49.5 mph) 3 mm/hr
(~ 0.12 in/hr)

[MJGarrison]

So we’ve talked about the track implications of a stronger/weaker storm. Are we continuing to consider it “stronger because of the additional thunderstorm activity and less sheared appearance, or weaker because of the reduced max winds and not so low pressure?


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[InfernoFlameCat]

So we’ve talked about the track implications of a stronger/weaker storm. Are we continuing to consider it “stronger because of the additional thunderstorm activity and less sheared appearance, or weaker because of the reduced max winds and not so low pressure?


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Weaker. Thunderstorms can be as intense as they want. Without a defined low, they will be less inclined to move in accordance to a ridge.

[caneman]

Am I missing something here? Weaker is supposed to be more Westward.

[tropicwatch]

So we’ve talked about the track implications of a stronger/weaker storm. Are we continuing to consider it “stronger because of the additional thunderstorm activity and less sheared appearance, or weaker because of the reduced max winds and not so low pressure?


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I was wondering the same thing. I'm not sold on the sharp turn northward.

[cheezyWXguy]

Fiona was hardly more than a low level swirl as it passed Guadeloupe, pretty clear the island did a number on it. However, wind shear appears to have quickly backed off since yesterday, and it’s a good sign for Fiona that bursting continues over the center. If this continues through the day, I suspect it will have its current issues worked out by tonight

[NDG]

I think next pass by the AF recon should find a better defined CoC and lower SLP as convection continues to re-fire right near it.

[InfernoFlameCat]

So we’ve talked about the track implications of a stronger/weaker storm. Are we continuing to consider it “stronger because of the additional thunderstorm activity and less sheared appearance, or weaker because of the reduced max winds and not so low pressure?


Sent from my iPad using Tapatalk

Weaker. Thunderstorms can be as intense as they want. Without a defined low, they will be less inclined to move in accordance to a ridge.

Aka more west. past the ridge.

[caneman]

I dont see how Puerto Rico would get direct impacts. Looks to me like it would have to move NW now.

[NDG]

I dont see how Puerto Rico would get direct impacts. Looks to me like it would have to move NW now.

12z TVCN is now right over the SW tip of PR.

[caneman]

I dont see how Puerto Rico would get direct impacts. Looks to me like it would have to move NW now.

12z TVCN is now right over the SW tip of PR.

I understand that but I'm looking at current conditions. Strength of storm, etc.. Looks to me it will be more like D.R. It would need to move NW now.

[Cachondo23]

Curious that none of the northern Lesser Antilles reported any sustained wind over 30 kts overnight. Guadeloupe (TFFF) reported 30kts gusting 50kts at 06Z, but 20 kts or less after that report. You can use the link below and go back to yesterday, or you can type in a stations 4-letter ICAO and check the obs over the past 24 hrs or more.

https://aviationweather.gov/metar

Well I would think St John's Island to the north of Guadeloupe probably had higher sustained winds but they stopped reporting after 9 PM.

You mean St John’s the capital of Antigua?