ATL: KAREN - Remnants - Discussion

[jlauderdal]

Bones is waiting to see what happens with Karen over the next few days. Even though Karen is really a tropical wave rather than a depression (a tropical depression classification really requires an LLC), tropical waves can develop into hurricanes. They have no memory of their previous lives. One such system that weakened to a wave but was reborn was Katrina in 2005. I'm not suggesting that Karen will become Katrina, just that there is a fair chance it will develop an LLC and regenerate. Maybe an equal chance it won't survive.

That's as bullish as you will see 57 for a weakend system like Karen. Doesn't mean it will develop.

[Blown Away]

Bones is waiting to see what happens with Karen over the next few days. Even though Karen is really a tropical wave rather than a depression (a tropical depression classification really requires an LLC), tropical waves can develop into hurricanes. They have no memory of their previous lives. One such system that weakened to a wave but was reborn was Katrina in 2005. I'm not suggesting that Karen will become Katrina, just that there is a fair chance it will develop an LLC and regenerate. Maybe an equal chance it won't survive.

That's as bullish as you will see 57 for a weakend system like Karen. Doesn't mean it will develop.

You know he wants to pull the plug, clearly the potential for something significant and track to the West is still there...

[GCANE]

Ring signature on rain-rate imagery indicates this is a long-duration vortical hot tower.

[AJC3]

I often talk about downshear reformation/consolidation of LLCs in weak sheared systems such as this. In this case, it's sort of bass-ackwards by 180 degrees in the sense that the shear is out of NE, thus displacing the convection toward the SW. More often than not it's the other way around. So instead of watching for vortex consolidation farther NE into the convection, as what occurred in Dorian, it's not out of the realm of possibility that this could try and take place farther SW of track. or at least tug it a bit in that direction. This could shift the track westward some, decreasing the chance for an escape out to the NE. Not saying it will happen like this, especially since Karen really doesn't have a well-defined COC anymore. Just something to consider...

[Aric Dunn]

I often talk about downshear reformation/consolidation of LLCs in weak sheared systems such as this. In this case, it's sort of bass-ackwards by 180 degrees in the sense that the shear is out of NE, thus displacing the convection toward the SW. More often than not it's the other way around. So instead of watching for vortex consolidation farther NE into the convection, as what occurred in Dorian, it's not out of the realm of possibility that this could try and take place farther SW of track. or at least tug it a bit in that direction. This could shift the track westward some, decreasing the chance for an escape out to the NE. Not saying it will happen like this, especially since Karen really doesn't have a well-defined COC anymore. Just something to consider...

yeppers it rarely happens but looking at sat and RECON sure seems like center is at the very least getting pulled/reformed to the SW some.

[AdamFirst]

Any particular reason why the storm is modeled to stay weak in the immediate (and forseeable) future?

[wx98]

I often talk about downshear reformation/consolidation of LLCs in weak sheared systems such as this. In this case, it's sort of bass-ackwards by 180 degrees in the sense that the shear is out of NE, thus displacing the convection toward the SW. More often than not it's the other way around. So instead of watching for vortex consolidation farther NE into the convection, as what occurred in Dorian, it's not out of the realm of possibility that this could try and take place farther SW of track. or at least tug it a bit in that direction. This could shift the track westward some, decreasing the chance for an escape out to the NE. Not saying it will happen like this, especially since Karen really doesn't have a well-defined COC anymore. Just something to consider...

I actually had this same thought this morning about it reforming to the SW...

[Visioen]

Any particular reason why the storm is modeled to stay weak in the immediate (and forseeable) future?

From last NHC discussion:

The environment ahead of Karen is forecast to remain quite hostile,
with dry mid-level air and strong northeasterly shear continuing
overnight.

[Blown Away]

Karen still pulsing...

[wxman57]

Bones is waiting to see what happens with Karen over the next few days. Even though Karen is really a tropical wave rather than a depression (a tropical depression classification really requires an LLC), tropical waves can develop into hurricanes. They have no memory of their previous lives. One such system that weakened to a wave but was reborn was Katrina in 2005. I'm not suggesting that Karen will become Katrina, just that there is a fair chance it will develop an LLC and regenerate. Maybe an equal chance it won't survive.

That's as bullish as you will see 57 for a weakend system like Karen. Doesn't mean it will develop.

You know he wants to pull the plug, clearly the potential for something significant and track to the West is still there...

Oh, I want to pull the plug, all right. I've had 3 days off since August 18th. Getting up at 3:30am-4am every day is getting tiring. I have 9 comp days saved up that I'd like to take. Plus, the Bahamas certainly don't need another storm. Die, Karen, die! There, I feel better...

[blazess556]

It appears to me Karen is holding together. Recon found a ~1008 mb closed LLC with plenty of westerly/southwesterly winds. Shear could also be decreasing slightly from earlier today as convection is firing and moving northward to the LLC.

18z SHIPS shows its downward from here in terms of shear. Of course, future land interaction with Peurto Rico lies ahead.

* ATLANTIC 2019 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* KAREN AL122019 09/23/19 18 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 30 28 27 26 26 29 34 39 45 47 51 53 57
V (KT) LAND 30 28 27 24 26 29 34 40 45 48 51 53 57
V (KT) LGEM 30 28 27 26 26 26 27 29 31 34 36 39 42
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 24 19 15 15 12 7 13 5 3 7 4 6 3
SHEAR ADJ (KT) 0 -1 -2 -1 -1 0 0 -2 0 -2 0 0 2
SHEAR DIR 32 28 21 14 15 20 57 360 19 272 296 286 226
SST (C) 29.8 29.6 29.6 29.8 29.7 29.4 29.3 29.3 29.0 28.7 28.7 28.7 28.6
POT. INT. (KT) 166 162 162 165 164 159 157 156 150 143 143 144 142
ADJ. POT. INT. 164 155 154 156 155 150 143 138 128 119 119 121 119
200 MB T (C) -52.8 -52.7 -52.8 -52.9 -52.9 -53.1 -53.0 -53.2 -53.2 -53.4 -53.6 -53.7 -53.8
200 MB VXT (C) 0.2 0.1 0.1 0.0 -0.1 -0.2 0.0 0.2 0.2 0.1 0.2 0.1 0.1
TH_E DEV (C) 9 9 9 8 8 7 7 6 4 4 3 4 5
700-500 MB RH 67 67 69 72 74 73 67 56 53 49 50 48 48
MODEL VTX (KT) 12 10 10 9 7 6 5 3 3 2 2 1 2
850 MB ENV VOR 3 8 7 15 11 -11 -22 -23 -18 -46 -28 -57 -37
200 MB DIV 26 20 16 23 48 30 42 25 21 11 5 1 7
700-850 TADV -6 -3 -1 -2 -4 -3 0 -1 0 0 -1 0 -1
LAND (KM) 283 184 89 -6 44 289 544 742 874 929 913 891 877
LAT (DEG N) 15.5 16.4 17.2 18.1 18.9 21.1 23.4 25.2 26.6 27.3 27.3 27.3 27.4
LONG(DEG W) 65.4 65.8 66.1 66.3 66.4 66.3 66.0 65.8 65.8 66.1 66.5 67.1 68.0
STM SPEED (KT) 11 9 9 9 9 12 10 8 6 2 2 4 4
HEAT CONTENT 74 84 77 74 81 80 34 29 29 26 27 27 29

[Aric Dunn]

looks like we are back to a TS.

[GCANE]

Ring structure is getting bigger.
Its trying to create a surface low and warm core.
If this keeps going for another couple hours, this will ramp up quickly.

[Aric Dunn]

It appears to me Karen is holding together. Recon found a ~1008 mb closed LLC with plenty of westerly/southwesterly winds. Shear could also be decreasing slightly from earlier today as convection is firing and moving northward to the LLC.

18z SHIPS shows its downward from here in terms of shear. Of course, future land interaction with Peurto Rico lies ahead.

* ATLANTIC 2019 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* KAREN AL122019 09/23/19 18 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 30 28 27 26 26 29 34 39 45 47 51 53 57
V (KT) LAND 30 28 27 24 26 29 34 40 45 48 51 53 57
V (KT) LGEM 30 28 27 26 26 26 27 29 31 34 36 39 42
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 24 19 15 15 12 7 13 5 3 7 4 6 3
SHEAR ADJ (KT) 0 -1 -2 -1 -1 0 0 -2 0 -2 0 0 2
SHEAR DIR 32 28 21 14 15 20 57 360 19 272 296 286 226
SST (C) 29.8 29.6 29.6 29.8 29.7 29.4 29.3 29.3 29.0 28.7 28.7 28.7 28.6
POT. INT. (KT) 166 162 162 165 164 159 157 156 150 143 143 144 142
ADJ. POT. INT. 164 155 154 156 155 150 143 138 128 119 119 121 119
200 MB T (C) -52.8 -52.7 -52.8 -52.9 -52.9 -53.1 -53.0 -53.2 -53.2 -53.4 -53.6 -53.7 -53.8
200 MB VXT (C) 0.2 0.1 0.1 0.0 -0.1 -0.2 0.0 0.2 0.2 0.1 0.2 0.1 0.1
TH_E DEV (C) 9 9 9 8 8 7 7 6 4 4 3 4 5
700-500 MB RH 67 67 69 72 74 73 67 56 53 49 50 48 48
MODEL VTX (KT) 12 10 10 9 7 6 5 3 3 2 2 1 2
850 MB ENV VOR 3 8 7 15 11 -11 -22 -23 -18 -46 -28 -57 -37
200 MB DIV 26 20 16 23 48 30 42 25 21 11 5 1 7
700-850 TADV -6 -3 -1 -2 -4 -3 0 -1 0 0 -1 0 -1
LAND (KM) 283 184 89 -6 44 289 544 742 874 929 913 891 877
LAT (DEG N) 15.5 16.4 17.2 18.1 18.9 21.1 23.4 25.2 26.6 27.3 27.3 27.3 27.4
LONG(DEG W) 65.4 65.8 66.1 66.3 66.4 66.3 66.0 65.8 65.8 66.1 66.5 67.1 68.0
STM SPEED (KT) 11 9 9 9 9 12 10 8 6 2 2 4 4
HEAT CONTENT 74 84 77 74 81 80 34 29 29 26 27 27 29

Shear just to the west 100 miles is 10 to 15 kts less.

[jlauderdal]

Ring structure is getting bigger.
Its trying to create a surface low and warm core.
If this keeps going for another couple hours, this will ramp up quickly.

https://i.imgur.com/BJ3kxjH.png

it cant ramp up too much, there is too much shear pressing on the system...we have to be careful looking at cool IR presentations

[wx98]

Finding FL and SFMR of 30-35 kts displaced well to the SE of the center

[Blown Away]

I often talk about downshear reformation/consolidation of LLCs in weak sheared systems such as this. In this case, it's sort of bass-ackwards by 180 degrees in the sense that the shear is out of NE, thus displacing the convection toward the SW. More often than not it's the other way around. So instead of watching for vortex consolidation farther NE into the convection, as what occurred in Dorian, it's not out of the realm of possibility that this could try and take place farther SW of track. or at least tug it a bit in that direction. This could shift the track westward some, decreasing the chance for an escape out to the NE. Not saying it will happen like this, especially since Karen really doesn't have a well-defined COC anymore. Just something to consider...

yeppers it rarely happens but looking at sat and RECON sure seems like center is at the very least getting pulled/reformed to the SW some.

Weak circulation pulsing convection to the SE...

[GCANE]

Equatorward Outflow Channel is setting up.

[Blown Away]

The modeling seems to be trending a little east before this west turn, however if you look at the NHC track it has been shifting very slightly to the west with each advisory.

[GCANE]

Ring structure is getting bigger.
Its trying to create a surface low and warm core.
If this keeps going for another couple hours, this will ramp up quickly.

https://i.imgur.com/BJ3kxjH.png

it cant ramp up too much, there is too much shear pressing on the system...we have to be careful looking at cool IR presentations

This is not IR, its rain rate.
High rain rate creates quick mid-level latent heating creating a warm core which is the key ingredient for a TC.