ATL: FRED - Post-Tropical - Discussion

[InfernoFlameCat]

There is clearly a closed low where PTC 06L is located.
https://i.postimg.cc/63DtGcfq/USA-12Z.gif

No

[robbielyn]

So close…some of those new convective bursts should help close this off for good. Not sure if dry air is an issue because the structure of the storm on satellite looks good.

Dry air is not an issue for this system. There is very little Sharan dust in the Atlantic.

Satellite imagery says otherwise. It is to its south and out ahead of it. The dry air in the midlayer is hampering convection. NHC says will be TS later today.

[Category5Kaiju]

So close…some of those new convective bursts should help close this off for good. Not sure if dry air is an issue because the structure of the storm on satellite looks good.

I'm pretty sure a NS will occur by the end of the day. Just has a bit more work to do in structuring itself

[BobHarlem]

 https://twitter.com/watkinstrack/status/1425111323961085952

[GCANE]

Surface winds will converge as this approaches PR.
Very likely it will close off then and should see a flare up in convection.

[xironman]

https://twitter.com/watkinstrack/status/1425111323961085952

I not sure exactly what the problem is. Obviously not a TC based on the lack of decent west winds despite any satellite presentation.

[NXStumpy_Robothing]

There is clearly a closed low where PTC 06L is located.
https://i.postimg.cc/63DtGcfq/USA-12Z.gif

NHC surface analysis does not outweigh reconnaissance data from a plane currently active within a storm. Surface analysis is essentially the best estimation that can be given from satellite imagery, which is why you may erroneously see closed lows where there are not and vice versa.

As of now, recon has yet to find evidence of westerly winds near the surface on the southern side of the wave axis, so this is not yet closed and therefore not yet a TC. I expect that to change by the end of the day, if not sooner, however.

[NDG]

Yet another wind shift but further SW from earlier pass.

URNT15 KWBC 101511
NOAA3 0106A INVEST HDOB 34 20210810
150130 1604N 06409W 9640 00448 0142 +228 +222 068006 009 014 000 00
150200 1602N 06408W 9642 00443 0141 +226 +223 039007 008 015 000 00
150230 1601N 06407W 9641 00447 0143 +227 +221 026004 006 016 000 00
150300 1559N 06407W 9639 00447 0142 +228 +222 354003 004 019 000 00
150330 1557N 06406W 9640 00447 0142 +229 +218 011001 003 017 000 00
150400 1556N 06405W 9641 00447 0142 +233 +221 066002 004 020 001 00
150430 1554N 06404W 9641 00447 0143 +230 +228 094001 002 021 002 00
150500 1552N 06404W 9642 00445 0143 +228 +227 198001 002 022 008 01
150530 1550N 06403W 9641 00448 0143 +230 +225 210002 003 017 003 00
150600 1549N 06402W 9641 00447 0142 +232 +217 239002 004 018 001 00
150630 1547N 06402W 9641 00445 0142 +232 +211 143000 001 019 003 00
150700 1545N 06401W 9641 00447 0142 +233 +211 179002 003 022 004 00
150730 1544N 06400W 9640 00447 0141 +231 +214 190003 004 023 003 00
150800 1542N 06359W 9640 00445 0141 +232 +206 184005 006 021 007 00
150830 1540N 06359W 9640 00445 0141 +229 +221 191005 006 022 008 00
150900 1539N 06358W 9641 00444 0140 +229 +218 185005 005 022 006 00
150930 1537N 06357W 9641 00443 0139 +230 +220 174004 005 023 007 00
151000 1535N 06356W 9641 00443 0139 +230 +224 178004 004 023 007 00
151030 1534N 06356W 9641 00442 0138 +230 +221 194003 004 020 006 00
151100 1532N 06355W 9641 00443 0138 +231 +225 197004 004 018 004 00

[ElectricStorm]

Yeah I agree with the NHC it's not there yet. Should be there by tonight or tomorrow morning though. The longer it stays weak though the better chance it has of getting through the islands less harmed.

[Aric Dunn]

no idea what they are doing over there.. they flew through the vortex on first pass.. cool great .. it was closed but small.. second pass they miss it clearly... so go back there..

they are just flying around the leftover trough axis... the vortex has not grown large enough to reach there yet..

we see this all the time..

[AutoPenalti]

So close…some of those new convective bursts should help close this off for good. Not sure if dry air is an issue because the structure of the storm on satellite looks good.

Dry air is not an issue for this system. There is very little Sharan dust in the Atlantic.

Not according to Levi.

[AutoPenalti]

Sounds like once again there's competing vorticites, until one consolidates, it's going to remain an open wave.

[SouthDadeFish]

The vortex isn't closed yet looking at the airborne radar data (I don't think I have permission to share this). There is also some tilting of the vortex, as the mid-level vortex is displaced to the southwest of the low-level center. The low-level vortex is also quite weak.

[Aric Dunn]

The vortex isn't closed yet looking at the airborne radar data (I don't think I have permission to share this). There is also some tilting of the vortex, as the mid-level vortex is displaced to the southwest of the low-level center. The low-level vortex is also quite weak.

That is all understandable.. but what is more logical.. flying around the decaying bottom end of the trough axis .... or the growing low to mid level circ with deep convection ?

it is much more likely that a vort max develops under the convection with the MLC then something that far south...

[GCANE]

Wind speed picked up dramatically on the west side of the axis.
Could be consolidating and closing off now.

[SouthDadeFish]

The vortex isn't closed yet looking at the airborne radar data (I don't think I have permission to share this). There is also some tilting of the vortex, as the mid-level vortex is displaced to the southwest of the low-level center. The low-level vortex is also quite weak.

That is all understandable.. but what is more logical.. flying around the decaying bottom end of the trough axis .... or the growing low to mid level circ with deep convection ?

it is much more likely that a vort max develops under the convection with the MLC then something that far south...

It is possible there was deep convection in that area that the plane had to avoid. Typically they do the best job they can trying to find the wind shift. In this case it seems they deviated around something, potentially. Luckily radar still sampled the region and NHC has access to this wind data in real-time too.

[GCANE]

AMSU estimating a very broad warm core.
Going to take time to consolidate

[wxman57]

So close…some of those new convective bursts should help close this off for good. Not sure if dry air is an issue because the structure of the storm on satellite looks good.

Dry air is not an issue for this system. There is very little Sharan dust in the Atlantic.

Dry air is definitely an issue in the eastern Caribbean: https://www.tropicaltidbits.com/analysis/models/gfs/2021081012/gfs_midRH_watl_2.png

[cycloneye]

 https://twitter.com/AndyHazelton/status/1425123921226092556

[xironman]

At least the MLC will be easy to track.