ATL: KARL - Post Tropical - Discussion

[GCANE]

Shear continues to decrease across the GoM.
Most notably in the BoC.
Improvement in the ARWB continues.
The RW appears to be pulling a bit north over the southern coast of TX.

[GCANE]

Seeing an overall drop in rain-rate area.

[Aric Dunn]

Looks like 93L's 700mb vort is breaking off from the vort south of the IoT
Same with 500mb vort.

Low level steering will collapse which is why models eventually trap whatever weak system they have and loop it around. but mid and upper level steering would take this north then probably NNE if it were to get up to a strong TS>

[hipshot]

Looks like 93L's 700mb vort is breaking off from the vort south of the IoT
Same with 500mb vort.

What is IoT?

[wxman57]

almost certainly a TD/TS now. Models showing a weak trough/low getting trapped. and deeper TS would have a good shot of lifting N/NNE.

A TS now? Based on what evidence of a well-defined LLC and 34 kt winds? The last scatterometer pass indicated a trof axis. Absolutely nothing would indicate a track to the north or north-northeast (toward the northern Gulf Coast or Florida). This is trapped in the BoC and will move into southern Mexico as the strong jet to its north digs south Wed/Thu.

[Landy]

[Aric Dunn]

almost certainly a TD/TS now. Models showing a weak trough/low getting trapped. and deeper TS would have a good shot of lifting N/NNE.

A TS now? Based on what evidence of a well-defined LLC and 34 kt winds? The last scatterometer pass indicated a trof axis. Absolutely nothing would indicate a track to the north or north-northeast (toward the northern Gulf Coast or Florida). This is trapped in the BoC and will move into southern Mexico as the strong jet to its north digs south Wed/Thu.

No

[GCANE]

Looks like 93L's 700mb vort is breaking off from the vort south of the IoT
Same with 500mb vort.

What is IoT?

Isthmus of Tehuantepec

[Aric Dunn]

Latest SCAT pass also showing a MESO vort up n the deeper convection. likely reformation/getting pulled farther north into convection throughout today.

[underthwx]

Looks like 93L's 700mb vort is breaking off from the vort south of the IoT
Same with 500mb vort.

Low level steering will collapse which is why models eventually trap whatever weak system they have and loop it around. but mid and upper level steering would take this north then probably NNE if it were to get up to a strong TS>

Hi Aric, I'm just curious. You say this has potential to track Northward, or NNE, but everything I have read on NWS products being made available thru their discussions, and so forth, do not make mention of this as a possibility. Please understand me, I'm not challenging your posts, nor do I mean to be argumentative, i include myself among those who have a high regard for you, here on S2K, and elsewhere. I'm simply trying to understand. If I'm missing something, I stand to be corrected. Many thanks Aric, have a great day!...

[boca]

almost certainly a TD/TS now. Models showing a weak trough/low getting trapped. and deeper TS would have a good shot of lifting N/NNE.

A TS now? Based on what evidence of a well-defined LLC and 34 kt winds? The last scatterometer pass indicated a trof axis. Absolutely nothing would indicate a track to the north or north-northeast (toward the northern Gulf Coast or Florida). This is trapped in the BoC and will move into southern Mexico as the strong jet to its north digs south Wed/Thu.

No

I thought a trough would always pull a storm N or NE I don’t understand south into Mexico.

[GCANE]

 https://twitter.com/AndyHazelton/status/1579874928165531649

[Aric Dunn]

Looks like 93L's 700mb vort is breaking off from the vort south of the IoT
Same with 500mb vort.

Low level steering will collapse which is why models eventually trap whatever weak system they have and loop it around. but mid and upper level steering would take this north then probably NNE if it were to get up to a strong TS>

Hi Aric, I'm just curious. You say this has potential to track Northward, or NNE, but everything I have read on NWS products being made available thru their discussions, and so forth, do not make mention of this as a possibility. Please understand me, I'm not challenging your posts, nor do I mean to be argumentative, i include myself among those who have a high regard for you, here on S2K, and elsewhere. I'm simply trying to understand. If I'm missing something, I stand to be corrected. Many thanks Aric, have a great day!...

It has a small window to deepen in the next 24 hours to find an escape route before the steering at all levels would trap it. all the models keep it weak hence why all the official forecasts anywhere dont show it. but it is clearly further along than expected. also have to watch out for reformations which would possibly further open the door.

[wxman57]

I thought a trough would always pull a storm N or NE I don’t understand south into Mexico.

Not in this case. A ridge is building down into the northern Gulf by Thursday. The jet stream will dig farther south, all the way to the BoC. This will push whatever is left south into Mexico. The low may loop around a bit in the BoC before it moves inland, but it's not leaving the BoC.

[GCANE]

CAPE is increasing rapidly across the entire GoM

[THC_Scientist]

almost certainly a TD/TS now. Models showing a weak trough/low getting trapped. and deeper TS would have a good shot of lifting N/NNE.

A TS now? Based on what evidence of a well-defined LLC and 34 kt winds? The last scatterometer pass indicated a trof axis. Absolutely nothing would indicate a track to the north or north-northeast (toward the northern Gulf Coast or Florida). This is trapped in the BoC and will move into southern Mexico as the strong jet to its north digs south Wed/Thu.

No

Wxman57 is a master of his craft, I wouldn’t second guess him. This is clearly not a tropical cyclone nor will it be.

[underthwx]

Low level steering will collapse which is why models eventually trap whatever weak system they have and loop it around. but mid and upper level steering would take this north then probably NNE if it were to get up to a strong TS>

Hi Aric, I'm just curious. You say this has potential to track Northward, or NNE, but everything I have read on NWS products being made available thru their discussions, and so forth, do not make mention of this as a possibility. Please understand me, I'm not challenging your posts, nor do I mean to be argumentative, i include myself among those who have a high regard for you, here on S2K, and elsewhere. I'm simply trying to understand. If I'm missing something, I stand to be corrected. Many thanks Aric, have a great day!...

It has a small window to deepen in the next 24 hours to find an escape route before the steering at all levels would trap it. all the models keep it weak hence why all the official forecasts anywhere dont show it. but it is clearly further along than expected. also have to watch out for reformations which would possibly further open the door.

Thankyou for clarifying Aric!....makes sense....and I too was surprised this morning when I looked at what has become 93L, on satellite...I appreciate your help...I'm always on a quest for understanding

[GCANE]

Low level steering will collapse which is why models eventually trap whatever weak system they have and loop it around. but mid and upper level steering would take this north then probably NNE if it were to get up to a strong TS>

Hi Aric, I'm just curious. You say this has potential to track Northward, or NNE, but everything I have read on NWS products being made available thru their discussions, and so forth, do not make mention of this as a possibility. Please understand me, I'm not challenging your posts, nor do I mean to be argumentative, i include myself among those who have a high regard for you, here on S2K, and elsewhere. I'm simply trying to understand. If I'm missing something, I stand to be corrected. Many thanks Aric, have a great day!...

It has a small window to deepen in the next 24 hours to find an escape route before the steering at all levels would trap it. all the models keep it weak hence why all the official forecasts anywhere dont show it. but it is clearly further along than expected. also have to watch out for reformations which would possibly further open the door.

If they tag this a TS, I would say this is one of the better model fails I have seen in some time.

[tropicwatch]

HH is still at cruising altitude approximately 27,000ft. The flight level winds have been coming down the further south it goes. Would be nice to get a couple more readings at this altitude. Latest was 33kts.

[GCANE]

Looking at GFS 500mb run-to-run, it appears the steering trof lost its negative tilt and is moving a bit north.