ATL: LAURA - Post-Tropical - Discussion

[Chris90]

I don't know if this has already been mentioned, but I think it's a bit interesting that Laura was the replacement name picked for Lili in 2002, which also affected the Caribbean and made landfall in Louisiana, not terribly far away from Laura's landfall point. They took similar paths too, Laura was just a little farther to the north as she traversed the Caribbean.

Really really similar peak intensities as well:
Laura 130kts/937mb
Lili 125kts/938mb

A bit eerie. Kind of like terrible twins separated by 18 years.

I mentioned it at some point, but I think it's buried somewhere in the depths of this thread. As I recall, Lili was supposed to go to Texas, but landfalled in central LA instead (I was living in NOLA at the time). She made me more than a little nervous at one point when she made a big northward wobble almost due south of the city. Especially since I didn't know at the time if it was a wobble or an actual turn.

Ahhh, my apologies on repeating the same info you already posted, I promise I wasn’t ignoring your post, these ATL threads move so fast I definitely skip pages when I catch up.

I don’t remember Lili all that well, except that my version of tracking her was watching the Weather Channel at 50 past the hour for the tropical update and dialing up AOL so I could go to the weather channel website.

I’ve never lived in a hurricane vulnerable area due to being a lifelong Midwesterner, but I imagine that must be very stressful watching the wobbles and wondering if you are going to get hit. In the Midwest we get a little heads up on severe weather events from the SPC obviously, but we don’t have to agonize over making a plan and deciding if we need to evacuate. If a tornado happens, we go to the basement, and that doesn’t rack up a monetary cost for evac that could end up being for naught.

I also feel like we’ve been going through a very 2000s-esque period of activity since 2017 with these big Gulf storms like Harvey, Michael, and now Laura. The 2005 vibes have been a bit too much this year. We keep setting early storm records, and now Laura felt a bit Katrina-like due to being a central gulf major impact in late August. I hope we enter a fish recurve pattern ASAP.

I hope all of you in the Caribbean and on the Gulf who have gone through Laura are starting to recover and everything is going well and you’re safe, sound, and doing well!

[CrazyC83]

** The highest flight-level winds were 148 kt, which translate to 133 kt at the surface.
** The SFMR peaked at 138 kt, however, that was likely a bit on the high side. SFMR readings become unreliable in shallow water.
** The strongest radar returns I saw were 156 kt at about 8,000 feet. That would support an intensity of 140 kt. However, the highest echoes may have been transient.
** The highest Dvorak rating I saw was T6.5. It didn't appear the white ring completely wrapped around. That would support 127 kt.
** The pressure I estimate at landfall was 936 mb. That was based on a combination of multiple land observations including 939 mb in Cameron and in the 940s inland, plus readings from aircraft of 936 to 939 mb when adjusted. Using the P-W relationship, that would translate to about 125-130 kt. It had a high bias throughout the storm though.
** Surface observations in Lake Charles clearly suggest a major hurricane hit, and that was likely before the absolute maximum winds hit. The station also failed. That clearly supports an intense hurricane.
* Conclusion: My estimate for the peak intensity was 135 kt. That was based on a blend of all the data, under the assumption the radar echoes were probably a tad high. The tree damage was similar to, but a touch less than, Michael.

I just wanted to say I fully agree with this, and underpinned my thinking behind 135 knots, as well. I doubt the NHC will upgrade to 140 knots in post-season analysis, although if they do, I'd be fascinated to see the data that underpinned it, of course.

Wasn't the 138 knot reading contaminated by rain, or was that the earlier 137 knot reading? I thought the highest unflagged SFMR was 133 knots (but I was switching tabs pretty rapidly during those last few passes, so I might have missed an unflagged 138 knot reading), on the same pass as the 137 knot reading, and then again just before landfall.

It wasn't so much contaminated by rain as opposed to by the shallow water below creating shoaling issues. I'd have been skeptical for all near-shore SFMR readings.

[Craters]

In hindsight, Eric Blake deserves a lot of credit for not over doing the westward shift on Tuesday morning. It was looking like a Houston storm after those early morning runs, but he kept the NHC forecast on the eastern side of the guidance with a landfall near the TX/LA border.

Agreed- and yet another example of humans doing a good job of blending scientific data, analysis, climatology, experience and good old fashioned forecasting for an outcome that exceeds any single computer model or group of models.

Probably should tell that to a physics professor I know who thinks meteorologists are useless and just can be replaced with computer models. They grew up in Israel and live in California now, so I'm really tempted to tell them "if you lived on the Gulf Coast you'd know better."

Rant mode ON:

Not that it matters, but that is the principal reason I left physics around umm...hmm... years ago: a prevailing snotty, dismissive attitude toward "real-world" science and the embracing of a "spherical cow" approach (https://en.wikipedia.org/wiki/Spherical_cow) to reality. Hurricanes, earthquakes, biological systems -- these are not the idealized systems of, say, particle physics. They're mind-bogglingly complex phenomena, and to consign them to the world of computer modeling as if they're subjects unworthy of a physicist's time is either a pathetic act of cowardice or a poorly veiled admission of ignorance.

Please understand that I'm not trying to disparage their contributions -- far from it, because fundamental physics is, after all, as fundamental as it gets in science. The real scientific heroes in the real world, however, are those who put their scientific careers on the line as they apply their knowledge to almost infinitely complex phenomena -- um, meteorologists trying to figure out tropical cyclones would be a good example, yes -- and willingly go very, very far out on a very, very flexible and shaky limb in a lives-on-the-line effort to help people and advance the science.

If meteorology, geology, oceanography, geophysics, or any number of other "real-world" scienctific disciplines could be considered in the awarding of Nobel prizes, attitudes would change faster than the decay of a µ-meson.

So, there.

Rant mode OFF:

[HurricaneEdouard]

Agreed- and yet another example of humans doing a good job of blending scientific data, analysis, climatology, experience and good old fashioned forecasting for an outcome that exceeds any single computer model or group of models.

Probably should tell that to a physics professor I know who thinks meteorologists are useless and just can be replaced with computer models. They grew up in Israel and live in California now, so I'm really tempted to tell them "if you lived on the Gulf Coast you'd know better."

Rant mode ON:

Not that it matters, but that is the principal reason I left physics around umm...hmm... years ago: a prevailing snotty, dismissive attitude toward "real-world" science and the embracing of a "spherical cow" approach (https://en.wikipedia.org/wiki/Spherical_cow) to reality. Hurricanes, earthquakes, biological systems -- these are not the idealized systems of, say, particle physics. They're mind-bogglingly complex phenomena, and to consign them to the world of computer modeling as if they're subjects unworthy of a physicist's time is either a pathetic act of cowardice or a poorly veiled admission of ignorance.

Please understand that I'm not trying to disparage their contributions -- far from it, because fundamental physics is, after all, as fundamental as it gets in science. The real scientific heroes in the real world, however, are those who put their scientific careers on the line as they apply their knowledge to almost infinitely complex phenomena -- um, meteorologists trying to figure out tropical cyclones would be a good example, yes -- and willingly go very, very far out on a very, very flexible and shaky limb in a lives-on-the-line effort to help people and advance the science.

If meteorology, geology, oceanography, geophysics, or any number of other "real-world" scienctific disciplines could be considered in the awarding of Nobel prizes, attitudes would change faster thanthe decay of a µ-meson.

So, there.

Rant mode OFF:

I think this is a pervasive attitude in certain sciences, and I found it frustrating as well when studying palaeontology and taking some ribbing from physics students. I suspect the psychological underpinnings are as simple as this: it is impossible to learn every science to an expert level, certain sciences are more quantitative than others and are (at least ostensibly) more difficult to learn at undergraduate or graduate level, and thus when an intelligent person learns one particular scientific discipline to an appreciable level, they can sometimes feel insecure that, while simultaneously feeling extremely knowledgeable about the natural world and being lauded for it, they have only a slightly greater understanding of another vital aspect of the natural world than a layperson and can very easily be exposed as ignorant in a few minutes of conversation even with a non-expert... or they can feel extremely, falsely confident their science (e.g. the perfect computer models of particle physics) can swallow up another. This is an actual case of the much-misused Dunning-Kruger Effect mixed with a culture of elitism and good-natured ribbing (my science is better than yours) taken too far from a relatively young age.

A wise person takes the inability of the human mind to learn everything in its lifespan as an opportunity to espouse the vastness and wonder of science, the wonder of ignorance, the wonder of learning something new and always, always having more to learn (which is my favourite thing about science and learning in general; I'll never get bored, I'll never get to the end, I'll never reach Level 50 and have to reroll a new character! ). An insecure person pretends their tiny sliver of the pie is the whole pie. Fortunately, most scientists and science students I've encountered are the former, but there's too many of the latter!

[BobHarlem]

Highest recorded surge was around 15ft

 https://twitter.com/ulmwxr/status/1299153532734431234

[AnnularCane]

I don't know if this has already been mentioned, but I think it's a bit interesting that Laura was the replacement name picked for Lili in 2002, which also affected the Caribbean and made landfall in Louisiana, not terribly far away from Laura's landfall point. They took similar paths too, Laura was just a little farther to the north as she traversed the Caribbean.

Really really similar peak intensities as well:
Laura 130kts/937mb
Lili 125kts/938mb

A bit eerie. Kind of like terrible twins separated by 18 years.

I mentioned it at some point, but I think it's buried somewhere in the depths of this thread. As I recall, Lili was supposed to go to Texas, but landfalled in central LA instead (I was living in NOLA at the time). She made me more than a little nervous at one point when she made a big northward wobble almost due south of the city. Especially since I didn't know at the time if it was a wobble or an actual turn.

Ahhh, my apologies on repeating the same info you already posted, I promise I wasn’t ignoring your post, these ATL threads move so fast I definitely skip pages when I catch up.

No need to apologize, it was just one sentence somewhere in a (very) active storm thread. Not sure I could find it myself now without a search.

[EquusStorm]

Impressive environment for tornadoes just east of the remnant center across Tennessee as soon as we get some peak heating in; very favorable low level wind profiles.

[bohai]

Highest recorded surge was around 15ft

https://twitter.com/ulmwxr/status/1299153532734431234

Which would make a lot of sense because it was definitely in the right front quad with winds from the south.

[PandaCitrus]

I think the NHC needs to do some work on the messaging for storm surge. The media is taking the surge estimate which is a reasonably worst case scenario number (10% probability event) and issuing guidance based on it. Over time, this is going to cause people to disregard the warnings. Better to clearly message 2 scenarios ... a 50% probability event and the 10% worst case scenario event.

[cheezyWXguy]

I think the NHC needs to do some work on the messaging for storm surge. The media is taking the surge estimate which is a reasonably worst case scenario number (10% probability event) and issuing guidance based on it. Over time, this is going to cause people to disregard the warnings. Better to clearly message 2 scenarios ... a 50% probability event and the 10% worst case scenario event.

This too would cause issues though. The public doesn’t do well with probabilities. It would be a disaster if the public prepared for the 50% chance and ended up getting the 10% chance.

[p1nheadlarry]

Agreed- and yet another example of humans doing a good job of blending scientific data, analysis, climatology, experience and good old fashioned forecasting for an outcome that exceeds any single computer model or group of models.

Probably should tell that to a physics professor I know who thinks meteorologists are useless and just can be replaced with computer models. They grew up in Israel and live in California now, so I'm really tempted to tell them "if you lived on the Gulf Coast you'd know better."

Rant mode ON:

Not that it matters, but that is the principal reason I left physics around umm...hmm... years ago: a prevailing snotty, dismissive attitude toward "real-world" science and the embracing of a "spherical cow" approach (https://en.wikipedia.org/wiki/Spherical_cow) to reality. Hurricanes, earthquakes, biological systems -- these are not the idealized systems of, say, particle physics. They're mind-bogglingly complex phenomena, and to consign them to the world of computer modeling as if they're subjects unworthy of a physicist's time is either a pathetic act of cowardice or a poorly veiled admission of ignorance.

Please understand that I'm not trying to disparage their contributions -- far from it, because fundamental physics is, after all, as fundamental as it gets in science. The real scientific heroes in the real world, however, are those who put their scientific careers on the line as they apply their knowledge to almost infinitely complex phenomena -- um, meteorologists trying to figure out tropical cyclones would be a good example, yes -- and willingly go very, very far out on a very, very flexible and shaky limb in a lives-on-the-line effort to help people and advance the science.

If meteorology, geology, oceanography, geophysics, or any number of other "real-world" scienctific disciplines could be considered in the awarding of Nobel prizes, attitudes would change faster than the decay of a µ-meson.

So, there.

Rant mode OFF:

Funny because last I checked, much of physics became an engineering/computational field well before geophysical fluid dynamics. Cold war was when it really got going (of course pioneers like Rossby, Bjerknes etc started before then). Furthermore, Einstein's general relativity is described mathematically by a system of equations larger than the GFD version of Navier-Stokes, and it is EXTENSIVELY modeled mathematically. They do computer simulations as much as mets do. Theory is only as useful as it's testing.

[PTPatrick]

I think the NHC needs to do some work on the messaging for storm surge. The media is taking the surge estimate which is a reasonably worst case scenario number (10% probability event) and issuing guidance based on it. Over time, this is going to cause people to disregard the warnings. Better to clearly message 2 scenarios ... a 50% probability event and the 10% worst case scenario event.

This too would cause issues though. The public doesn’t do well with probabilities. It would be a disaster if the public prepared for the 50% chance and ended up getting the 10% chance.

Agreed. Surge is one of those things you simply to have to overwarn. If they would have hedged and said oh well the surge could be 8 feet or 16 people would hedge and not get out. And if the storm had been 20 miles west lake Charles would be a mess. You underwarn for for wind and people have some very scary nights in the bathtub. You underwarn for surge and people drown. Saw it with Katrina...they spoke loud and clear that surge would be bad but they tended to hug the normal surge models...they compared to Camille but nobody ever said it could be worse than Camille. If they had I think more people would have left. I think surge exceeded normal model expectations across all of Mississippi and Mobile, and people died and or found themselves on roofs. My god mother swam thru swamp in a nightgown to meet a man And his goat in a rowboat. My friends parents hid in their attic in Biloxi until it was over...including a 90 year old on a walker with a fractured hip who had to be pulled up there. Bottom line is there are probably some places in this country where you can hedge on surge due to normal angles of approach and coastal topography. You just can’t take the chance from a houston to the panhandle. I do think we need more emphasis on surge and we have seen that since Katrina and Rita and Ike in general. Maybe some of that language is an over correction. I do think that in general most locals understand their risk and if you are realistic about what can happen they will take heed. I know growing up in a surge zone nobody ever needed to be told to get out. But the bigger wetter storms of recent years still managed to catch many people off guard. Many people nowadays still don’t understand their elevations and their relative risks, esp as coastal areas have grown.

[Stormcenter]

I’m late to the party here in reference to
discussing how the NHC did with Laura.
I would give them a C- overall. I mean at one
point they Laura around Tallahassee.

[wx98]

I’m late to the party here in reference to
discussing how the NHC did with Laura.
I would give them a C- overall. I mean at one
point they Laura around Tallahassee.

Having the landfall time and place nailed to the hour and within a mile almost 90 hours out while the storm was south of Cuba very much deserves more than a C-. Any complicated track is going to be off at the very beginning.

[wx98]

Impressive environment for tornadoes just east of the remnant center across Tennessee as soon as we get some peak heating in; very favorable low level wind profiles.

https://horsesnhurricanes.files.wordpress.com/2020/08/download-5.png

There have been 4 tornado warnings so far in Middle TN. Nothing definite to have touched down as of yet.

[Craters]

I’m late to the party here in reference to
discussing how the NHC did with Laura.
I would give them a C- overall. I mean at one
point they Laura around Tallahassee.

I really have to disagree with that grade. Overall, yes, they were off in the beginning -- when it mattered the least. When push came to shove, though, and lives were on the line real-time, they absolutely, positively nailed it from close to three days out.

To me, that's A+ performance, without a doubt or reservation.

[Tireman4]

I’m late to the party here in reference to
discussing how the NHC did with Laura.
I would give them a C- overall. I mean at one
point they Laura around Tallahassee.

I really have to disagree with that grade. Overall, yes, they were off in the beginning -- when it mattered the least. When push came to shove, though, and lives were on the line real-time, they absolutely, positively nailed it from close to three days out.

To me, that's A+ performance, without a doubt or reservation.

I have to agree, I will give them an A.

[Steve]

I’m late to the party here in reference to
discussing how the NHC did with Laura.
I would give them a C- overall. I mean at one
point they Laura around Tallahassee.

There were two tropical storms with a pattern needing to resolve. I don't think many people will agree with you, but you are entitled to your opinion. If you were being sarcastic, sorry for missing that. Track moving toward landfall, they get an A+. Intensity, maybe a B- as they underforecast though did put out many notices that their intensity guidance might be underdone.

[toad strangler]

I’m late to the party here in reference to
discussing how the NHC did with Laura.
I would give them a C- overall. I mean at one
point they Laura around Tallahassee.

There were two tropical storms with a pattern needing to resolve. I don't think many people will agree with you, but you are entitled to your opinion. If you were being sarcastic, sorry for missing that. Track moving toward landfall, they get an A+. Intensity, maybe a B- as they underforecast though did put out many notices that their intensity guidance might be underdone.

No better unit than the NHC.

[toad strangler]

 http://twitter.com/weatherdak/status/1299196156057063424