Hurricane Hurricane Beryl

[slenker]

The pressure can be explained by small size and background sea level pressures. Smaller storms have much tighter pressure gradients, especially if they’re being superimposed on by a ridge.

What’s puzzling is how did such stupidly extreme damage occur when similarly strong storms like Maria or Otis, both storms that struck mountainous terrain as Cat 4/5 storms did not.

I can only assume beryl had unusually strong and persistent wind gust for its strength, it was moving at 22mph which probably gave its northern eyewall even more of a boost in the form of wind gust.

On a side note, the fourth picture is unreal. That’s the type of damage I’d expect from a EF4 tornado, not a hurricane of any kind. Reminds me of Andrew, honestly probably more intense than even that.

 

[jiharris0220]

On a side note, the fourth picture is unreal. That’s the type of damage I’d expect from a EF4 tornado, not a hurricane of any kind. Reminds me of Andrew, honestly probably more intense than even that.

Way more intense than Andrew.

Both Michael and Andrew left a lot of slash pine and palm trees with their foliage still intact, and debarking was few and far between with both storms.

You could still pick out a few pieces of leaves that luckily survived in those hurricanes.

Typically low end cat5 storm damage, Beryl debarked at least 30% of the vegetation it touched, and I’m just basing that off of what I saw.

There isn’t a single piece of leaf even remotely left in these photos, not even the ground hugging brush were sparred. Which only occurs in high end cat5 storms, I have not seen that phenomenon in low end cat5 storms.

 

[Sawmaster]

After looking over at everything regarding wind damage in the windward islands, I can confidently say cat5 winds, (even high end) occurred in Carriacou, Petite Martinique, and especially Union Island.

I’ll go as far to say it was just as bad in Irma, even though there’s no evidence that Beryl was a cat5 at landfall. Although this can easily be explained by the mountains in which the infrastructure is built on.

Without further a do, here’s the physical evidence, with vegetation. In the first photo, all vegetation has been 100% denuded, regardless of the type, even the palm trees were reduced to match sticks.

In the second photo, you can even see moderate debarking on some of the use to be trees. Especially the third photo, the vegetation has that classic “bleached/burned” look, a phenomena that I’ve seen exclusive to only high end cat5 winds.

The fourth photo is the most impressive to me, as the damage here to vegetation is something I haven’t seen in many ef4 rated tornadoes. Just a slew of granulated pieces of debarked branches and trees that look like they went through a nuclear blast.

The last photo more or less shows the same thing, and that even trees with large trunks and branches were no match whatsoever.

I’ve already shown you guys the structural damage in earlier photos, mainly with the surprising amount of reinforced concrete buildings destroyed.

I’m telling you, there are way, waaay more, to the point that I’ve haven’t seen so many destroyed since Irma and even Haiyan. There’s so many of these destroyed structures it’s pointless to show all of them.

It’s to the point where the only explanation I can think of is that this storm must of had unusually high gust even for its strength, well into the 200mph range. Which is a phenomenon that can occur in rapidly strengthening hurricanes combined with mountainous terrain.

Which is the only explanation that makes sense other than saying that Beryl was a straight up 160knot storm. Because not even Maria in Dominic and Puerto Rico did anything like this despite supposedly being the stronger storm.

Finally, the death toll for beryl in the windward islands is 17, with one missing, all wind related fatalities involving people dying from flying debris and being crushed by heavy concrete walls that they thought should’ve protected them.

It’s very rare for a hurricane to get about 10 fatalities directly from wind, and if it does happen the explanation is shoddy construction. Obviously, this isn’t one of those situations where the structures failed because they were weak, but a situation where the structures failed because the hurricane was unfortunately just that strong.

I haven't seen or heard of much in detail, but some damage might be overstated here. I remember that Dorian was said to have damaged "reinforced concrete" structures when the pics clearly showed CMU construction with concrete-filled cells (often only at the corners) and similar construction of "beams" across openings and along the top of the walls where "trough block" should have been use but wasn't. Instead the beam strength lay mostly in lintels under the block, which does not have nearly as much lateral strength. Rebar was used in these locations, and was likely adequate for the methods used. Far better than CMU only, or flled cells without rebar, but nowhere near what we in the US understand to be "Reinforced Concrete" although locally that is apparently the usual description for this type of construction.

Having said all that, such structures would still be quite strong and resistant to winds of perhaps low Cat 4 level- maybe less. And true reinforced concrete as we understand the term here, also needs to have at least ~6 inches on any side to have good strength, with 8 inches being much stronger. Anything but a slab-on-ground at ~4 inches is quite weak comparatively even with best practices for rebar and other reinforcements. Union Island seems to have been the most devastated as best I can tell, but most of the structures there were not of good strength because the of lower economic conditions found in these small islands compared to the large islands with better economies.

So I won't comment directly on strength or rating, my point is only to clarify the differences in definition regards "reinforced concrete" and elucidate on some of it's foibles in use. And once again I will state my wish that hurricanes windspeeds were rated at maximum instantaneous velocity same as tornadoes which would eliminate the ambiguity about gusts..

 

[jiharris0220]

I haven't seen or heard of much in detail, but some damage might be overstated here. I remember that Dorian was said to have damaged "reinforced concrete" structures when the pics clearly showed CMU construction with concrete-filled cells (often only at the corners) and similar construction of "beams" across openings and along the top of the walls where "trough block" should have been use but wasn't. Instead the beam strength lay mostly in lintels under the block, which does not have nearly as much lateral strength. Rebar was used in these locations, and was likely adequate for the methods used. Far better than CMU only, or flled cells without rebar, but nowhere near what we in the US understand to be "Reinforced Concrete" although locally that is apparently the usual description for this type of construction.

Having said all that, such structures would still be quite strong and resistant to winds of perhaps low Cat 4 level- maybe less. And true reinforced concrete as we understand the term here, also needs to have at least ~6 inches on any side to have good strength, with 8 inches being much stronger. Anything but a slab-on-ground at ~4 inches is quite weak comparatively even with best practices for rebar and other reinforcements. Union Island seems to have been the most devastated as best I can tell, but most of the structures there were not of good strength because the of lower economic conditions found in these small islands compared to the large islands with better economies.

So I won't comment directly on strength or rating, my point is only to clarify the differences in definition regards "reinforced concrete" and elucidate on some of its foibles in use. And once again I will state my wish that hurricanes windspeeds were rated at maximum instantaneous velocity same as tornadoes which would eliminate the ambiguity about gusts..

You may be correct in your assessment, but I can assure you that the damage is most definitely not overstated.

The structures in Union island despite most being unreinforced concrete, had plenty of structures made of solid concrete with rebar inside them.

And as far as I’ve seen, none appeared to have been made out of CMU. But regardless of the specifics of how strong the structures are, tree damage doesn’t lie.

I like to compare and contrast vegetation damage between strong hurricanes, because the degree of damage regarding vegetation is much more consistent with winds speeds.

You can genuinely tell the difference between a low end cat5 impact like Micheal or Andrew vs a high end cat4 impact like Charley or Ian. I’ve never seen a 130knot cat4 debark trees or strip every single piece of vegetation.

Maria in Puerto Rico and Beryl are exceptions though because the mountainous areas clearly experienced cat5 damage.

But Beryl is on an entirely different class, if someone showed me that fourth picture without context and told me to guess what tropical cyclone did that I would’ve guessed Haiyan or Irma.

 

[warneagle]

On a side note, the fourth picture is unreal. That’s the type of damage I’d expect from a EF4 tornado, not a hurricane of any kind. Reminds me of Andrew, honestly probably more intense than even that.

Might be kind of the same phenomenon as was observed in Andrew with the smaller mesovortices in the eyewall causing more intense damage than the "regular" eyewall winds did.

 

[jiharris0220]

Might be kind of the same phenomenon as was observed in Andrew with the smaller mesovortices in the eyewall causing more intense damage than the "regular" eyewall winds did.

Even though it would seem so, I don’t think it’s likely.

“Mini swirls” leave noticeable tracks in their path, it’s very easy to tell where those MV tracked.

Even Harvey had mini swirl damage, left hand side of all three apartments demolished in a straight line.

I have not seen this occur with Beryl.

What likely happened is that Beryl had much stronger wind gust for its intensity when taking into account rapid strengthening, fast forward speed (22mph), and the high terrain.

And now that I think about it, Maria and Otis were both weakening right before landfall, Maria from 150knots to 135knots, and Otis from 145knots to 140knots.

So despite the high terrain, which definitely makes it easy for cat5 winds to occur, the high end cat5 winds likely didn’t mix to the surface, not even down to the mountains.

So I will simply use that as an explanation as to why beryls damage is more impressive than the aforementioned storms.

 

[Equus]

I need to remember to come here more often during tropical weather instead of just severe weather lmao, tree damage in hurricanes is definitely a thing I have spent some time researching. I posted a now very outdated thread with many now-dead links on S2K several years ago comparing a ton of historical violent landfalls around the world. Some conclusions:

- A storm undergoing rapid strengthening causes far more violent tree damage than a weakening one of the same intensity (much higher gusts)
- Even a little elevation can bring in some insane gusts, with trees obliterated on hills in high end storms
- Tree species composition matters a lot at lower categories, but above the 145-150kt threshold, matters very little
- Some historical hurricane landfall intensities may be a good bit stronger or weaker than officially estimated based on consistency of tree damage vs. intensity

I hadn't seen those vegetation damage pics; that sort of shredded, lifeless vegetation obliteration is hard to get below 150kt, or at least 145kt. Forests of St Vincent and the Grenadines are composed of rainforest, some dry scrub forests, and at least some surviving coastal mangroves, in the Windwards Islands ecoregion comprised of both a lot of endemics and South American species. That of course is dramatically different than the forests of US/Cuba/Bahamas where you'll be dealing with slash pine or other subtropical pines, but the threshold where this starts making a difference is in the 120kt range or so. Notably, the southern Windwards have very few historical hurricanes on record to compare to of that intensity. Ivan is really the only comparable case for the southern Grenadines and Grenada, passing through as a 110kt storm on a strengthening trend. Ivan, on a strengthening trend, actually caused some really impressive tree damage for a category three storm; I'd argue it probably produced category four winds as vegetation on hills was shredded very effectively to category four typical levels in Grenada...



... however, on the other 110kt landfall in AL during a weakening trend, tree damage was not very impressive at all. Lots of uprooting, a bunch of snapped pines but not as whole forests, just here and there. Clearly storms intensifying with very strong surface winds and gusts (which we see in SFMR vs flight level profiles in intensifying storms!) do a lot more tree damage. Beryl was definitely extremely intense and RI'ing as it moved through, and I'd bet surface gusts were extremely strong before mixing settled in. We had the 197kt sonde not too far off the surface (906mb level) the following morning, so I would not at all be shocked if there were extreme 150+kt wind gusts on that elevated terrain where the forests were shredded during the RI periods, which of course SFMRs were not working very well for. Forward speed is definitely a factor too. Fast moving very intense storm rapidly intensifying with the RFQ moving onto a mountainous island = perfect recipe for extreme tree damage

 

[slenker]

I need to remember to come here more often during tropical weather instead of just severe weather lmao, tree damage in hurricanes is definitely a thing I have spent some time researching. I posted a now very outdated thread with many now-dead links on S2K several years ago comparing a ton of historical violent landfalls around the world. Some conclusions:

- A storm undergoing rapid strengthening causes far more violent tree damage than a weakening one of the same intensity (much higher gusts)
- Even a little elevation can bring in some insane gusts, with trees obliterated on hills in high end storms
- Tree species composition matters a lot at lower categories, but above the 145-150kt threshold, matters very little
- Some historical hurricane landfall intensities may be a good bit stronger or weaker than officially estimated based on consistency of tree damage vs. intensity

I hadn't seen those vegetation damage pics; that sort of shredded, lifeless vegetation obliteration is hard to get below 150kt, or at least 145kt. Forests of St Vincent and the Grenadines are composed of rainforest, some dry scrub forests, and at least some surviving coastal mangroves, in the Windwards Islands ecoregion comprised of both a lot of endemics and South American species. That of course is dramatically different than the forests of US/Cuba/Bahamas where you'll be dealing with slash pine or other subtropical pines, but the threshold where this starts making a difference is in the 120kt range or so. Notably, the southern Windwards have very few historical hurricanes on record to compare to of that intensity. Ivan is really the only comparable case for the southern Grenadines and Grenada, passing through as a 110kt storm on a strengthening trend. Ivan, on a strengthening trend, actually caused some really impressive tree damage for a category three storm; I'd argue it probably produced category four winds as vegetation on hills was shredded very effectively to category four typical levels in Grenada...

View attachment 29313

... however, on the other 110kt landfall in AL during a weakening trend, tree damage was not very impressive at all. Lots of uprooting, a bunch of snapped pines but not as whole forests, just here and there. Clearly storms intensifying with very strong surface winds and gusts (which we see in SFMR vs flight level profiles in intensifying storms!) do a lot more tree damage. Beryl was definitely extremely intense and RI'ing as it moved through, and I'd bet surface gusts were extremely strong before mixing settled in. We had the 197kt sonde not too far off the surface (906mb level) the following morning, so I would not at all be shocked if there were extreme 150+kt wind gusts on that elevated terrain where the forests were shredded during the RI periods, which of course SFMRs were not working very well for. Forward speed is definitely a factor too. Fast moving very intense storm rapidly intensifying with the RFQ moving onto a mountainous island = perfect recipe for extreme tree damage

Fascinating post. The links on a lot of the imagery for older cyclones understandably fail to work now, so I would be very interested in seeing the pictures for Zoe that were comparable to Winston. I also used to question Cyclone Winston’s true intensity being 884 mbar before, but those pictures are pretty absurd and support such an intensity.

 

[Equus]

Fascinating post. The links on a lot of the imagery for older cyclones understandably fail to work now, so I would be very interested in seeing the pictures for Zoe that were comparable to Winston. I also used to question Cyclone Winston’s true intensity being 884 mbar before, but those pictures are pretty absurd and support such an intensity.

Here's the Zoe pic, luckily the Internet Archive managed to snag it before that page went down. Mainly was looking at the hillside back there devoid of anything green and some of the foreground trees stripped and shredded of branches, but looking at it again, this is probably pretty comparable to other 145-150kt storms instead of being way worse



Low res but some other pretty good pics from Tikopia here; definitely looks like lots of shredding and debarking https://www.rambocam.com/archive/zoe.html

 

[jiharris0220]

Fascinating post. The links on a lot of the imagery for older cyclones understandably fail to work now, so I would be very interested in seeing the pictures for Zoe that were comparable to Winston. I also used to question Cyclone Winston’s true intensity being 884 mbar before, but those pictures are pretty absurd and support such an intensity.

Winston is an interesting case, despite it’s immaculate satellite presentation which is becoming of a high end cat5, the tree damage it did to Fuji doesn’t look anything more than a 130knot/135knot impact.

I’ve looked at countless photos, and clearly vegetation was thoroughly stripped, but not shredded down or debarked. And the palm trees didn’t look to bothered by the wind either.

Storms in the western and southern pacific south of 20 degrees north have very cold CDOs due to high tropopause, and so that can tend to inflate Dvorak estimates.

My guess is that Winston was a 135-140knot storm, and the low pressure can again be contributed to extremely low background sea level pressures. Winston was quite a large storm too so pressure gradients weren’t particularly steep.

 

[jiharris0220]

Here's the Zoe pic, luckily the Internet Archive managed to snag it before that page went down. Mainly was looking at the hillside back there devoid of anything green and some of the foreground trees stripped and shredded of branches, but looking at it again, this is probably pretty comparable to other 145-150kt storms instead of being way worse

View attachment 29319

Low res but some other pretty good pics from Tikopia here; definitely looks like lots of shredding and debarking https://www.rambocam.com/archive/zoe.html

Yea, for some reason the damage Zoe did looked a lot worse back then.

Those palm trees in the back even from here I can tell they have palm fronds battered but intact.

And the other trees have only minor debarking on them, Zoe was a slow mover too.

The damage definitely doesn’t have the “bleached/burned” look that was present in storms like Irma, Haiyan, and (I can’t believe I’m saying this), Beryl, so a low to mid end cat5 impact looks reasonable just basing of off a damage standpoint.

 

[Equus]

This is the worst Winston damage I could find for that post (thanks Internet Archive) - probably as bad as it gets in the SHem given the rarity of high end landfalls there but the burned, grey and brown scorched look of the really high end TCs is a lot more limited. With the slow movement one would expect slightly worse damage but it's still pretty impressive.



Fantala had some pretty high end stuff too; snapped and denuded palms and did a good bit of debarking.

Speaking of high end landfalls though, here's Dorian on Grand Bahama, in Pinus caribaea var. bahamensis forest

 

[jiharris0220]

This is the worst Winston damage I could find for that post (thanks Internet Archive) - probably as bad as it gets in the SHem given the rarity of high end landfalls there but the burned, grey and brown scorched look of the really high end TCs is a lot more limited. With the slow movement one would expect slightly worse damage but it's still pretty impressive.

View attachment 29320

That’s the photo that kinda convinced me Winston was not a strong as Satellite estimates suggest, even though it looks impressive at first glance, (as in high end cat5 impressive) upon closer inspection, there’s a little to much in the way of branches still intact.

And even though the shot is quite far away, I still to this day fail to find any sort of sign of debarking in this photo. Although it passes the “100% denuded test” and so 135knot to 140knots is what I’d but the windspeed at this particular location.

 

[Equus]

I think the key is long duration high (130-140kt) winds will definitely defoliate every branch and strip stuff bare, but to strip branches off too and get into the serious debarking you need to be in the 150kt+ range; that said, a lot of that may have to do with the acceleration of winds, with higher gusts being able to rip branches off more effectively - more points for storms undergoing RI and producing extreme gusts with their weird mixing ratios (definitely points for Beryl)

 

[jiharris0220]

Going back to Michael and Andrew, here is a comparison between the two regarding tree damage, particularly pines, and hardy trees.

These damage picks of Micheal are classic examples of low end cat5 damage, spotty areas of debarking, and 100% denution of none pines.

Same thing with Andrew with the low end cat5 damage, 100% denution of none pines and again with minor debarking here and there.

In comparison to the Beryl picks I showed earlier, really puts things into perspective in that high end cat5s are an order of magnitude worse.

So I don’t blame people who say there should be a new level in the SSHWS, that being cat6. Although it’s really not necessary whatsoever and would cause more complications than not.

 

[jiharris0220]

Here is an island impacted by beryl that I’ve forgotten about, Canouan. It’s a smaller island like Petite Martinique that’s located approximately 9-10miles north of Union Island.

And looking at the damage, I’m even more convinced Union island experienced high end cat5 winds. Because the damage sustained in Canouan looks a lot more of what you would expect from a high end cat4 impact.

Notice the vegetation damage, 100% denuded, but no visible debarking, palm trees battered but still have palm fronds, and the large trees still have their branches mostly intact.

This is what I’d expected Union Island and Petite Martinique to look like, keep in mind Canouan was on the outer edge of the northern eyewall, and the damage is still this impressive. No doubt a symptom of the fast forward speed due to the Caribbean trades that allowed for such high winds to occur despite being on the outer edge.

 

[jiharris0220]

Mayreau, an island just south of Canouan, experienced the middle part of the northern eyewall, and as expected, the damage is a bit worse.

These pictures show what you would expect from a low end cat5 impact. With trees sustaining heavy loss of branches and debarking being few and far between.

It’s actually interesting to see the difference levels of damage on each island. It’s fascinating that you can actually tell what’s high end cat4, low end cat5, and high end cat5.

I send my condolences to the people who inhabit these islands, they will have a much tougher time recovering as they don’t have the benefit of being on a mainland. As these small populations usually tend to be forgotten by mainstream media sources.

 

[Sawmaster]

Jonathan Petramala has revisited Caricau and Petit Martinique, and posted a very touching video of the current conditions there.

 

[jiharris0220]

So I thought I should let y’all know that google earth has updated the imagery of the leeward islands right after hurricane Beryl.

You guys can go see yourselves but all I have to say the damage isn’t any less impressive even from space.

I honestly can’t recall when a tropical cyclone produced such complete destruction from pure winds alone other than Andrew.

But that was shoddy mobile home parks that got annihilated, these were full blown homes made of reinforced concrete. Although the roofs by themselves were definitely not a strong suit and blew away easily.

The tree damage is the worst I’ve seen from satellite since Irma, maybe just a tad worse, though to be fair to Irma, she hit the BVI with the “weak side” of her eyewall and still managed to do high end cat5 damage on top of the hills.

 

[Sawmaster]

Jonathan Petramala just dropped his follow-up vid of Caricau. Includes much new footage including their hotel room losing the roof and the eye coming and going continuously as it happened, plus more damage footage. Plus a lot with the people there.