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WxWatcher007

Major Hurricane Laura

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Just now, Windspeed said:
4 minutes ago, jpeters3 said:
There are clearly several regions on the south end where echoes drop below 20 dBz though.  So the intense eyewall convection is fairly degraded down there.  I'm not saying that recon will find this region completely devoid of convection and bright moonlight shining in, and these asymmetric eyewall structures are somewhat common in event intense hurricanes.  All i'm saying is that this may but a damper on continued strengthening.  But this seemed to have ignited a massive controversy.

It is what it is. There is light echoes there for certain. But just look at the northern semicircle. This vorticity maximum isn't weakening anytime soon. It might have reached a steady-state. Good enough. Unfortunately the damage had already been cemented for landfall impacts.

 

That surge. I can't imagine the water about to rise along areas like Cameron and Holly Beach.

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Just now, Eskimo Joe said:

Probably birds. This has been observed before on other storms and even confirmed by some of the buoy cams.

I just suggested that this could be damage done to the oil rigs down there. Laura is spinning right over all of them. 

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Just now, hlcater said:

Nah, but Michael's eyewall was more intense all around. It still strikes me as odd that the southern eyewall is having a hard time pushing 20dbz and has for most of the day.

What about this one? This is frustrating because I am absolutely a know nothing, but we have this same discussion with every landfalling storm. The backside from the radar always looks terrible...I won't claim to know specific terms but this is extremely common.

 

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So to throw more fuel on the fire, Knabb on TWC just weighed on the side of "It's radar attenuation, the eyewall looks strong on IR."

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2 minutes ago, Windspeed said:
6 minutes ago, jpeters3 said:
There are clearly several regions on the south end where echoes drop below 20 dBz though.  So the intense eyewall convection is fairly degraded down there.  I'm not saying that recon will find this region completely devoid of convection and bright moonlight shining in, and these asymmetric eyewall structures are somewhat common in event intense hurricanes.  All i'm saying is that this may but a damper on continued strengthening.  But this seemed to have ignited a massive controversy.

 

It is what it is. There are light echoes there for certain. But just look at the northern semicircle. This vorticity maximum isn't weakening anytime soon. It might have reached a steady-state. Good enough. Unfortunately the damage has already been cemented for landfall impacts.

Yeah, I think the point of my original post was missed.  It seemed to have been interpreted as, "this has an open eyewall, it is going to weaken into an open wave before landfall."  In reality, i was just making an observation and speculating as to the influence of this observation on future strengthening.  To set the record straight:

2 images from different radars at the same time.  Along the line I have drawn, which goes from the eye out into the open air outside the storm, there are no echoes > 15 dBz.

 

RADAR.png

RADAR2.png

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Just now, KPITSnow said:

What about this one? This is frustrating because I am absolutely a know nothing, but we have this same discussion with every landfalling storm. The backside from the radar always looks terrible...I won't claim to know specific terms but this is extremely common.

 

The thing is though, that weakness is there from multiple different radars and in the same spot. I don't think this is an artifact that is being generated by the 88Ds. They are probably exaggerating it to an extent, but the fact the presentation is similar from several angles lends to legitimacy here. 

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Dr. Knabb (former NHC director) just addressed the southern eyewall radar issue... Stated that it likely was not degraded completely, and rather was being blocked by the high-returns from the northern eyewall. Lets let the former NHC director put that argument to bed...

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Rick Nab on weather channel just said, it could be that the radar can’t see through the northern part of the eyewall very well, so that’s why the southern eyewall looks somewhat open.  If that’s what folks mean by attenuation..I apologize.  Just repeating what Dr Nab said. 
 

He was the NHC Director after all...so??? 

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AF recon and NOAA recon may end up being in the eye at the same damn time. 

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1 minute ago, mimillman said:

This looks like an eyewall  replacement cycle. Were Laura still in the central Gulf, no doubt this would end up a strong cat 5, but the eyeball won’t have time to fully replace before landfall.

Definitely not any ERC ongoing.

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Just now, WinterWolf said:

Rick Nab on weather channel just said, it could be that the radar can’t see through the northern part of the eyewall very well, so that’s why the southern eyewall looks somewhat open.  If that’s what folks mean by attenuation..I apologize.  Just repeating what Dr Nab said. 
 

He was the NHC Director after all...so??? 

Explain this to me then.  How does "attenuation" show up in the same location from two completely different vantage points.  From KHGX, it should be on the eastern side, but it shows up on the south?

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Dr. Rick Knabb on TWC just was saying that the southern eyewall looks degraded on radar likely because it's 1) still far from radar and 2) that northern band is so intense that the beam is struggling to see through it to get better image of the southern eyewall. No y'all can get your panties out of a bunch ;)

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1 minute ago, Derecho! said:

So to throw more fuel on the fire, Knabb on TWC just weighed on the side of "It's radar attenuation, the eyewall looks strong on IR."

No no, he said he "thinks it might be" but not definitive enough evidence. I may be 8k miles across the globe but I'm watching the same feed.

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Looks like AF300 found FL winds of 145kt... ~166mph. SFMR seemed notably lower than you would expect.

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2 minutes ago, jpeters3 said:

Yeah, I think the point of my original post was missed.  It seemed to have been interpreted as, "this has an open eyewall, it is going to weaken into an open wave before landfall."  In reality, i was just making an observation and speculating as to the influence of this observation on future strengthening.  To set the record straight:

2 images from different radars at the same time.  Along the line I have drawn, which goes from the eye out into the open air outside the storm, there are no echoes > 15 dBz.

 

RADAR.png

RADAR2.png

Maybe we're using Laura as bait to catch a larger w pac typhoon. 

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1 minute ago, jpeters3 said:

Yeah, I think the point of my original post was missed.  It seemed to have been interpreted as, "this has an open eyewall, it is going to weaken into an open wave before landfall."  In reality, i was just making an observation and speculating as to the influence of this observation on future strengthening.  To set the record straight:

2 images from different radars at the same time.  Along the line I have drawn, which goes from the eye out into the open air outside the storm, there are no echoes > 15 dBz.

Where are the two radar sites located?  Are the images from exactly the same time.  Clearly the southern eyewall has lower intensity precipitation.  But depending on where the radars are located, there could also be some attenuation of the beams.  In one image, it looks like the radar is located almost due north.  In the other, it looks more like to the NNW.  I don't see how there wouldn't be some attenuation due to an intense hurricane eyewall.  But if one radar site is actually located far to the east or west, then maybe you are correct.

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Everyone is speculating, even Rick Knabb.  I'm having a conversation with another professor who is an expert in TCs, and he agrees with my explanation of the phenomena.  I also maintain that nobody has explained why the features shows up in the same spot from two different radars.  I guess we'll see if the VDM contains any remarks.

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1 minute ago, jpeters3 said:

Explain this to me then.  How does "attenuation" show up in the same location from two completely different vantage points.  From KHGX, it should be on the eastern side, but it shows up on the south?

Might want to ask the former NHC Director pal...cuz he’s the one who said it. Then he also referenced the infrared satellite view and said it looks very healthy.  His words, not mine . 

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