Cat 5 Major Hurricane Patricia

[wxmx]

 

I got a call today from a NWS met who was just in Mexico surveying the landfall zone with a ground team. (He called me to thank me for my report, which they found helpful.) They found some very intense tree damage near the open coast, and I'm eager to see these pics, as they'll be more indicative of the max winds than what we had a couple of miles inland.

 

So you had to spread the eagerness, right? >  

[andyhb]

you couldn't be more wrong in your original post about what a Cat 5 or 200 mph winds would do. yes building codes are more stringent but 200 mph is going to level everything, lets not forget gusts not sustained.

 

TCs do not have the same vertical velocities that tornadoes do. Since this added vertical component counteracts gravity, this added lifting makes a tornado with 200+ mph winds (and a 75-100+ mph vertical velocity) much more destructive than a hurricane with 200+ mph winds (given similar duration of this level of windspeed) over the areas that are affected.

[Normandy]

Josh,

 

What are your thoughts re: the difference in the two sides of the storm?  I'm assuming the cyclone approached you from the south, so u first went thru the NE eyewall and then the SE (correct me if i'm wrong)?  Have you ever seen such a discrepancy in the winds on either side?

[Ginx snewx]

TCs do not have the same vertical velocities that tornadoes do. Since this added vertical component counteracts gravity, this added lifting makes a tornado with 200+ mph winds (and a 75-100+ mph vertical velocity) much more destructive than a hurricane with 200+ mph winds (given similar duration of this level of windspeed) over the areas that are affected.

I never made a comparison. I took exception with his statement about 200 mph winds not leveling houses due to more stringent construction codes. Josh I have no idea what Patricia came ashore at. Thats for reanalysis, but I believe Doppler measured 318 in an OK tornado, another Josh.

[Normandy]

^Thats the problem though.  Construction Codes have everything to do with the amount of damage 200 mph hurricane wind will do to structures.  Or the amount of damage ANY hurricane wind will do.  If construction codes had nothing to do with it, then Josh would never chase any Category 5 cyclones because he would never survive.  Josh could chase the most violent cyclone this earth has to offer, right on the coast, and survive if he is in an enclosed stairwell of a concrete parking garage (and above surge obviously).  This is just one example, but the point is there are structures that these winds will level, and there are those they wont.  its that simple.

 

The point of this whole statement is that people need to understand hurricane damage potential and use that knowledge to act accordingly.  This is the reason you have mass evacuations of major cities....even by those who are MILES inland and protected from surge.  And its the same reason people are disappointed when a Category 5 cyclone hits and a city isn't erased.  The sensationalist nature of this new generation is really to blame, and its why everytime i see "bye bye Florida" i cringe because its an asinine statement.  Not saying you feel this way but it really is a problem with some posters on this forum.

[Ground Scouring]

I got a call today from a NWS met who was just in Mexico surveying the landfall zone with a ground team. (He called me to thank me for my report, which they found helpful.) They found some very intense tree damage near the open coast, and I'm eager to see these pics, as they'll be more indicative of the max winds than what we had a couple of miles inland.

Along with the wind-testing of the anemometer at the Cuixmala biological station, this survey--and your data!--should be very useful in gauging the true strength of PATRICIA at landfall. I'm very gratified to see that this historic event is being (and has been!) documented to the best of everyone's ability. Hopefully, the data will culminate in raw material suited to in-depth studies, aside from that contained in the official, post-seasonal report. I would also love to see Mexico make investments in new radar sites.

[Ginx snewx]

^Thats the problem though. Construction Codes have everything to do with the amount of damage 200 mph hurricane wind will do to structures. Or the amount of damage ANY hurricane wind will do. If construction codes had nothing to do with it, then Josh would never chase any Category 5 cyclones because he would never survive. Josh could chase the most violent cyclone this earth has to offer, right on the coast, and survive if he is in an enclosed stairwell of a concrete parking garage (and above surge obviously). This is just one example, but the point is there are structures that these winds will level, and there are those they wont. its that simple.

The point of this whole statement is that people need to understand hurricane damage potential and use that knowledge to act accordingly. This is the reason you have mass evacuations of major cities....even by those who are MILES inland and protected from surge. And its the same reason people are disappointed when a Category 5 cyclone hits and a city isn't erased. The sensationalist nature of this new generation is really to blame, and its why everytime i see "bye bye Florida" i cringe because its an asinine statement. Not saying you feel this way but it really is a problem with some posters on this forum.

tell ya what if a Cat 4-5 ever threatened my area, very very unlikely, I am out of Dodge. Flying debris,trees alone,never mind 90 % of the houses were built pre 92. I have seen what a lousy 1 can do.You can stay and trust your house, you will have a great story to tell.

[NorthNJwx]

I echo what others have said about the footage -- it's phenomenal, both from a human interest perspective and, of course, a meteorological perspective.  Amazing job.  Your Kestrel data is incredibly valuable as well.

 

 

Re: categories... A storm's landfall category is based on the estimated absolute maximum wind occurring in the storm over water or at the open coast when it comes ashore. These max winds would not occur 2.5 n mi inland over rough/coarse terrain. Therefore, the wind damage pics in Emiliano Zapata wouldn't show Cat-5 damage, even if the storm was Cat 5. Expecting Cat-5 damage pics in Emiliano Zapata completely disregards the physics of these things, the terrain, and the friction that occurs.

 

Yes.  Exactly.  Sustained wind measurements are super sensitive to exposure, even moreso than gusts.  I have a weather station on a barrier island in southern NJ, with a clear fetch (over 5+ miles of open water and salt marsh) to the W and WNW and varying degrees of less-than-perfect exposure to the rest of the compass rose, so I've been lucky enough to be able to observe this phenomenon first-hand.

 

As an example, a March 2014 post-cold frontal gale produced a max 2-min sustained wind of WNW 47 mph and max 3-second gust of 54 mph at my anemometer, which is about 11m AGL.  That's a gust factor of 1.15 -- which is essentially indicative of marine exposure.  But to my NE, on the other hand, there are other houses directly upwind of me.  So, during a nor'easter about a month ago, my max 2-min sustained wind was NE 34 and max 3-second gust was 51.  That's a gust factor of 1.5 -- far from marine exposure.  A station on the open beach, in contrast, probably would've measured a max 2-min sustained wind of at least 45 mph during that storm.  A nearby, fully-exposed WeatherFlow station, for example, actually measured a max 5-min wind of 44 mph.

 

So, truly, the maximum sustained wind on land during any landfalling TC necessarily occurs, quite literally, at 10m above the open beach.  If you were to instead measure the wind 50 feet inland and  25 feet behind a row of 10' tall dune shrubs, your measurements would be noticeably lower -- as even obstructions well below the height of the anemometer will result in a reduction in sustained wind (and an increase in gust factor).

[thewxmann]

TCs do not have the same vertical velocities that tornadoes do. Since this added vertical component counteracts gravity, this added lifting makes a tornado with 200+ mph winds (and a 75-100+ mph vertical velocity) much more destructive than a hurricane with 200+ mph winds (given similar duration of this level of windspeed) over the areas that are affected.

 

 

Re: categories... A storm's landfall category is based on the estimated absolute maximum wind occurring in the storm over water or at the open coast when it comes ashore. These max winds would not occur 2.5 n mi inland over rough/coarse terrain. Therefore, the wind damage pics in Emiliano Zapata wouldn't show Cat-5 damage, even if the storm was Cat 5. Expecting Cat-5 damage pics in Emiliano Zapata completely disregards the physics of these things, the terrain, and the friction that occurs.

 

These are important points. You can't compare a 145 kt Cat 5 to an EF4 tornado. The friction alone would cut down the maximum sustained winds by 10-20% (a rough estimate) a few miles inland. You can probably increase those reduction estimates in a hilly area with a bunch of trees. And tornadoes have such a strong vertical component to wind velocities. Those put a lot more load on structures (e.g. roofs) than horizontal winds.

[ncforecaster89]

Just for the record, I've yet to see any pics posted online, thus far, that exceed anything I've witnessed first-hand following 115 kt. wind gusts (not suggesting the storm wasn't much more intense, as my best educated guess is 125-130 kt. MSW).

Secondly, the tornado damage scale has always been used (since its inception) to provide a best estimate of wind speed to observed damage correlation following high-wind events that weren't tornadic in nature.

That said, let's consider Andrew and the post-storm damage survey that was conducted by no less than Dr. Ted Fujita, himself. I am attaching the map that corresponds to the aforementioned post-storm analysis.

The scale of miles on the map below can be calculated by the longitude markers (80.4, 80.5, etc.). Each .1 change is 6 miles.

The solid black triangles are F-3 damage points from the study by Dr. Fujita. F-3 is 162-209 mph. As you can see, several of the F-3 markers are over 5 miles inland.

In short, Andrew serves as an example of a 145 kt. category-five hurricane that did bring Cat 5 winds upwards of 5 nm inland from the land/sea interface. The main reason being that it was rapidly intensifying at landfall, as opposed to Patricia, which was rapidly weakening well before doing the same. The other obvious factor was the difference in terrain.

The main point of this particular post is to simply point out that category-five intensity wind speeds have theoretically been observed up to 5 miles inland from the shoreline. And, the tornado damage scale is used by the NWS to determine a best estimated guess as to the maximum winds produced by a particular high-wind event, based on damage alone.

All this aside, it's highly unlikely one will discover any category-five hurricane damage because Patricia didn't come ashore at category-five intensity. All of the observed data and emperical evidence strongly supports that conclusion, at this time.

[Normandy]

I am not going to argue with you especially about this.  But you are missing the entire point of what everybody else is saying to you because you have an agenda for Patricia not being a 5 at lantdall.

[Windspeed]

Patricia will likely be left a Category 5 at landfall. Even though the inner eyewall was open/weakening and the overall pressure was rising rapidly from the 879mb measured six hours prior to landfall, the sharp pressure gradient change experienced at Josh's location is among the most violent that has been recorded. The crazy backside winds in his video match up with the western eyewall, which was still intact even if the eye was only partially closed on radar and much weaker/open in the eastern semi-circle. The front half of the eye was weak and the backside of the eye was extremely violent.

 

I'd imagine had Patricia made landfall even a few hours later, the inner eyewall would have completely collapsed as the outer eyewall was choking it off. The gradient would have had time to flatten out by then. I will say this with absolute certainty though: Josh, you're lucky!! As frightening as the experience was on the backside where you probably experienced 130-140kt winds at your location, can you imagine if Patricia had not been undergoing an ERC prior to landfall? Recon had recorded and evidenced the outer wind maxima, cloud-filling and rapid rise in pressure, so we know the inner eye was weakening even if it was still a Cat 5. But had Patricia came ashore at near peak intensity, you're hotel would have been completely annihilated. That extra 30kts of wind, and also taking into consideration a fully closed eyewall, the front side of the storm would have also been violent. The interior of your hotel may not have survived both sides of the storm.

[ncforecaster89]

I am not going to argue with you especially about this. But you are missing the entire point of what everybody else is saying to you because you have an agenda for Patricia not being a 5 at lantdall.

I presume this post was directed to me. If so, I want to commend you on such an excellent scientific response to my post.

Secondly, I don't know why some of you continue to resort to unjustified personal attacks and/or false assumptions, such as I supposedly have some sort of agenda; whatever that means.

I'm simply sharing my opinion based on actual scientific data that strongly suggests Patricia was not at category-five intensity upon landfall. How hard is that to understand? Another incorrect statement you made is that "everyone" agrees it was category-five at landfall...which also isn't true.

Oh yeah, what is this grandiose "point" I'm supposedly missing because of my alleged agenda?

[Normandy]

Because you are ignoring factors/data that indicate it was a Category 5.  There are arguments for both and that is the point you don't get.  You keep beating it down our throats, making matter of fact declarations that Patricia was not a Category 5 when in actuality you CANNOT prove it one way or another.  That is what makes it seem like you have an agenda.

[winterymix]

...

I got a call today from a NWS met who was just in Mexico surveying the landfall zone with a ground team. (He called me to thank me for my report, which they found helpful.) They found some very intense tree damage near the open coast, and I'm eager to see these pics, as they'll be more indicative of the max winds than what we had a couple of miles inland.

...

 

Josh, the implication is that the NWS considers you an expert correspondent with sound

scientific integrity.

[1900hurricane]

Starting to see the vegitation damage floating around Twitter now, and at first glance, it looks pretty brutal. Here are some before and after shots from John Galetzka.

 

 

 

 

 

I don't have any expertise in differentiating between category 4 and category 5 damage, so I'm not going to speculate about that, but the damage to that forestland will likely take many years to completely undo.

[ncforecaster89]

Because you are ignoring factors/data that indicate it was a Category 5. There are arguments for both and that is the point you don't get. You keep beating it down our throats, making matter of fact declarations that Patricia was not a Category 5 when in actuality you CANNOT prove it one way or another. That is what makes it seem like you have an agenda.

Uh, no. I have never made any "matter of fact declarations that Patricia was not a category 5" at landfall. Rather, I've consistently stated that it's "highly likely" it wasn't, and the available data/evidence "strongly suggests" Patricia had weakened below category-five intensity at landfall. Those are my opinions based on my own best educated guess; nothing more and nothing less.

That said, my best educated guess is based on factual data and the available evidence. Since I've consistently stated it's "highly likely" Patricia had weakened below category-five strength at landfall...I'm also saying there's still a slight chance Patricia did retain category-five intensity.

The simple fact (intentionally using this word now) is that no one will ever truly know for certain whether Patricia came ashore at category-four or category-five intensity. One of the main reasons being that there wasn't any RECON data obtained within the last hour preceding landfall. Consequently, we'll never know just how much the MSWs had actually decreased during the final three hours before the center crossed the coast.

We are very fortunate to have the data from both Josh and the biological station...but, neither can answer the aforementioned question. Thus, the final determination will always remain more subjective than cases where a TC wasn't rapidly weakening at such an astonishing rate, for instance.

Oh yeah, my so-called agenda is simply trying my best to make the most scientifically accurate estimation of Patricia's landfall intensity, and doing so in a completely unbiased and objective manner; something alot of others aren't doing, themselves.

[Stebo]

Uh, no. I have never made any "matter of fact declarations that Patricia was not a category 5" at landfall. Rather, I've consistently stated that it's "highly likely" it wasn't, and the available data/evidence "strongly suggests" Patricia had weakened below category-five intensity at landfall. Those are my opinions based on my own best educated guess; nothing more and nothing less.

That said, my best educated guess is based on factual data and the available evidence. Since I've consistently stated it's "highly likely" Patricia had weakened below category-five strength at landfall...I'm also saying there's still a slight chance Patricia did retain category-five intensity.

The simple fact (intentionally using this word now) is that no one will ever truly know for certain whether Patricia came ashore at category-four or category-five intensity. One of the main reasons being that there wasn't any RECON data obtained within the last hour preceding landfall. Consequently, we'll never know just how much the MSWs had actually decreased during the final three hours before the center crossed the coast.

We are very fortunate to have the data from both Josh and the biological station...but, neither can answer the aforementioned question. Thus, the final determination will always remain more subjective than cases where a TC wasn't rapidly weakening at such an astonishing rate, for instance.

Oh yeah, my so-called agenda is simply trying my best to make the most scientifically accurate estimation of Patricia's landfall intensity, and doing so in a completely unbiased and objective manner; something alot of others aren't doing, themselves.

Can you just let the analysis happen and then if it comes back that you are right then so be it. I mean this might be the most beaten horse I have ever seen around here. I mean at this point, the discussion has grown tired, you have outlined why you think it wasn't a category 5. Now you are just being repetitive and expecting everyone to suddenly have an epiphany and agree with you...  

[ncforecaster89]

Can you just let the analysis happen and then if it comes back that you are right then so be it. I mean this might be the most beaten horse I have ever seen around here. I mean at this point, the discussion has grown tired, you have outlined why you think it wasn't a category 5. Now you are just being repetitive and expecting everyone to suddenly have an epiphany and agree with you...

I understand your point, but why shouldn't I be permitted to respond to others who reference my posts? That's what I just did in the preceding post.

As I noted in the aforementioned post, the final NHC report will be the official determination, but it will still be more subjective in nature than otherwise might be the case. So, it wouldn't necessarily mean I am right even if they come back with a 130 kt. category-four landfall intensity...just as it wouldn't necessarily mean I was wrong if they retained it's current category-five designation.

All I'm doing is critically examining all of the available evidence (the most basic premise of science) and sharing my own best educated guess as to how it translates to Patricia's landfalling intensity. No different than anyone else.

[ncforecaster89]

Can you just let the analysis happen and then if it comes back that you are right then so be it. I mean this might be the most beaten horse I have ever seen around here. I mean at this point, the discussion has grown tired, you have outlined why you think it wasn't a category 5. Now you are just being repetitive and expecting everyone to suddenly have an epiphany and agree with you...

Maybe I should emphasize that hurricane history, research, and the reanalysis of past TCs is most fascinating to me. The purpose of my posts aren't meant to disparage the opinions of others, that are based on factual evidence, who may simply interpret the evidence differently than myself.

All that being said, I've continued to examine the available data/evidence, as well as how it compares to other TCs of similar intensity, during the past week. These are things I have yet to share. I haven't done so for the specific reason you alluded to (a loss of interest in this particular discussion), and may never do so.

[Rainman]

No one said you aren't permitted to reply.  They are just begging you to stop.

[Stebo]

No one said you aren't permitted to reply.  They are just begging you to stop.

This, ncforecaster you have belabored your point several times over. There is no point to keep replying with the same stuff we have already seen, several people have come out and said as such. No one is trying to snuff out your thoughts, we just don't need them rehashed daily as if we are all clueless with no memory.

[Rjay]

Ok enough. NCforecaster, we get it.

I wasn't kidding. You're not breaking any rules and you're respectful but you're driving me nuts! Please move on until further analysis is made public.

[Ginx snewx]

I wasn't kidding. You're not breaking any rules and you're respectful but you're driving me nuts! Please move on until further analysis is made public.

dont read the thread or ignore his posts,don't understand the angst,geezus.He has every right to respond. Never was a fan of censorship and thats exactly what you are doing. There are features you can employ to not see his posts or just scroll through or dont click. Hive thought is the worst.

[Rjay]

dont read the thread or ignore his posts,don't understand the angst,geezus.He has every right to respond. Never was a fan of censorship and thats exactly what you are doing. There are features you can employ to not see his posts or just scroll through or dont click. Hive thought is the worst.

This isn't hive thought. This is me moderating. He made his point and it's time to move on.

[HurricaneJosh]

I think it comes down to conversational etiquette. Of course everyone should express their views. Of course. But if you're at a social gathering and someone repeats the same viewpoint again and again-- even if that viewpoint is totally valid-- it's natural for other participants to grow weary and object to the repetition. It's not about free speech or even the merits of the viewpoint being expressed. (It could be that PATRICIA wasn't a Cat 5 at landfall, and arguments can be made either way.) It's about basic conversational etiquette.

[HurricaneJosh]

Back on topic...

 

Postanalysis on PATRICIA is underway. I've been in contact with NHC specialists who are reviewing my data, and also a NOAA team that did a two-day survey of the landfall zone. The NOAA team's report should be released any day-- I've seen an early draft-- and I'll share a link when it's publicly available. Their survey, which factors in stuff like which way the trees fell, puts the track of the center basically right over my hotel. I disagree slightly with their timing-- they have the center passing over my location between 6:20 and 6:40 pm CDT, whereas my lowest pressure (and the lull) happened ~6:05 to 6:15 pm, so I've given them this feedback.

 

The NOAA report assesses a substantial area of Cat-4 wind damage that includes Emiliano Zapata (the largest town in the cyclone's inner core, and where I was). That finding makes perfect sense, whether it was a strong Cat 4 or Cat 5.

[thewxmann]

I think it comes down to conversational etiquette. Of course everyone should express their views. Of course. But if you're at a social gathering and someone repeats the same viewpoint again and again-- even if that viewpoint is totally valid-- it's natural for other participants to grow weary and object to the repetition. It's not about free speech or even the merits of the viewpoint being expressed. (It could be that PATRICIA wasn't a Cat 5 at landfall, and arguments can be made either way.) It's about basic conversational etiquette.

 

Message boards need a like or upvote botton for posts like these.

[HurricaneJosh]

Message boards need a like or upvote botton for posts like these.

 

Hey, thanks.

[ncforecaster89]

I think it comes down to conversational etiquette. Of course everyone should express their views. Of course. But if you're at a social gathering and someone repeats the same viewpoint again and again-- even if that viewpoint is totally valid-- it's natural for other participants to grow weary and object to the repetition. It's not about free speech or even the merits of the viewpoint being expressed. (It could be that PATRICIA wasn't a Cat 5 at landfall, and arguments can be made either way.) It's about basic conversational etiquette.

Conversational etiquette? Please! No one seems to object much to some who resort to unjustified personal attacks and false accusations. If you guys would read my posts in the context and order for which they're made...you'd see I'm most often simply replying to those who respond to my own.

I suspect if I consistently made posts repeatedly arguing for a category-five landfall designation...I highly doubt I'd be subjected to the same type of ridicule or objection. Just saying.