Cat 5 Major Hurricane Patricia

[ncforecaster89]

Katrina was a bigger storm though in terms of size, right?

 

Correct!  But, I believe the point he may have been alluding to is the significant difference it makes between a storm that is coming ashore while intensifying (or steady state) and one that is rapidly weakening...with an equivalent central pressure.  

[ncforecaster89]

Big difference between Katrina analogy which was a large cyclone ~vs~ Patricia which was very compact. Smaller tightly wrapped tropical cyclones with a very smaller inner core typically remain very strong for a longer period of time. And lol at all this hoopla over whether it was a CAT 5 or not. Arguing semantic less than 3 days after landfall is pointless.

 

Actually, the opposite is true.  In general, a small TC will both rapidly intensify and also rapidly weaken, all other things being equal. 

[JC-CT]

I should have simply stated that it was no longer unprecedented.

My mistake....but saying that the system did not weaken a bit prior to LF is every bit as incorrect.

Pure and utter folly that you guys geek out over if it stronger or weak.

Storm was strong. wait 2 days prior to calling a bust.

This is Mexico for weenie's stake.

Matt

Actually, this is a weather board, where people come to discuss weather.

Is he supposed to hop on the first available flight to Mexico to personally assist with the recovery efforts, or is posting on some obscure internet forum that he prays for the well-being of people directly affected by the storm sufficiently helpful?

[Ginx snewx]

these are from Fb,the motel Josh was in, doesn't look Cat 5 ish

[ncforecaster89]

 NC, about the landfall "point" as per the NHC, don't they just give a location to the nearest tenth of a degree and then a location from the map? There would be a 10-mile uncertainty associated if we choose 105.0 W and not 105.1 or 104.9. I think Josh was two miles east of 105.0 W, and that means he could have been anywhere between 7 miles east to 3 miles west of the actual landfall, then factor in that the storm might have tracked slightly east of due north but probably not enough to adjust that range of uncertainty.

 

Yes, Roger, you are correct that they do round the coordinates to the nearest tenth of a degree.  That said, I was calculating the apparent distance (in nm) by the coordinates for Josh's intercept location and the geometric center shown on satellite.  Granted, that too could be a little off on exact distance.  If the distance was off in any direction, there appears to be little doubt Josh was still to the E of the center.  These are all valid points that I'm sure the NHC will consider.  

 

The biggest issue will likely remain the extreme rate of filling that was occurring in the last 5.5 hours prior to landfall (observed by RECON 2.75 hours preceding landfall) and the significant degradation of the satellite appearance during that time.

 

Whatever the NHC ultimately determines, I just hope they get it right and the various data supports their decision.

[TropicalAnalystwx13]

I'm not sure if it was mentioned here, but a NOAA HADS station at an elevation of 295ft in Cuixmala measured peak sustained winds of 185 mph gusting to 211 mph. This observation is unofficial until it's been quality controlled, but if it turns to valid then not only did Patricia fail to weaken below Category 5 strength before landfall, but it also was actually stronger than initially assessed.

[OSUmetstud]

I'm not sure if it was mentioned here, but a NOAA HADS station at an elevation of 295ft in Cuixmala measured peak sustained winds of 185 mph gusting to 211 mph. This observation is unofficial until it's been quality controlled, but if it turns to valid then not only did Patricia fail to weaken below Category 5 strength before landfall, but it also was actually stronger than initially assessed.

Standard sea level reduction gives 136 kt. (19 percent at 300 ft).

[Roger Smith]

Well here's two more bits of actual evidence:

 

Facebook posting from Punta Perula confirming no local deaths, extensive damage especially to trees and power likely to be out for up to four days although some power available from generators made available in advance of the storm by the government. (search for Punta Perula Huerta Jalisco on facebook, go down below pinned earlier posts)

 

Video shot nearby at San Mateo (to see it, search for San Mateo Jalisco on facebook) which to my eye looks cat-3 intensity, palm trees flapping around violently, occasional sheets of rain but nearby structures not coming apart, looks to be shot looking southeast through a window.

 

Sorry I can't link directly, I am having issues with my facebook page admin status getting into the http line which is rendering the saved link useless to anyone but me.

 

The big question now would seem to be, what happened at Cayeres? I have sent an e-mail to my contact at the resort near Punta Perula asking for any specific information.

[Amped]

Standard sea level reduction gives 136 kt. (19 percent at 300 ft).

 

People will just have to take a chill pill until more info and a professional assessment is released.  Hopefully in the future NHC gets funds some sort of a program to place ruggadized mobile weather stations ahead of every major land-falling storm.

[wxmx]

Inner eyewall was still present, so like it happens with intensification, winds take time to lower during weakening (if the inner eyewall had completely collapsed, then a more dramatic wind reduction would have been expected). And as I alluded earlier, if the experts find the weather station to be reliable, then that's all the evidence needed to support cat 5 at landfall

[Ginx snewx]

Inner eyewall was still present, so like it happens with intensification, winds take time to lower during weakening (if the inner eyewall had completely collapsed, then a more dramatic wind reduction would have been expected). And as I alluded earlier, if the experts find the weather station to be reliable, then that's all the evidence needed to support cat 5 at landfall

Do you think that the entire hour plus that station recorded Cat 5 winds is accurate? With the forward speed and size that seems highly unreliable. Josh estimated a 20 minute period of  high intensity, damage pictures do not represent winds of that magnitude. plus the 162.3 sustained for 19 mins is a huge red flag I am suspect.

[Rjay]

Do you think that the entire hour that station recorded Cat 5 winds is accurate? With the forward speed and size that seems highly unreliable. Josh estimated a 20 minute period of high intensity, damage pictures do not represent winds of that magnitude. I am suspect.

Wasn't the forward motion of the storm 14 to 15 mph? If so the NHC report Cat 5 winds were up to 15 miles out from the center. I think it's plausable but idk if it's accurate yet.

[Ginx snewx]

Wasn't the forward motion of the storm 14 to 15 mph? If so the NHC report Cat 5 winds were up to 15 miles out from the center. I think it's plausable but idk if it's accurate yet.

i added the image above 162.3 sustained for 19 straight mins, I suspect this anemometer had technical issues.

[Rjay]

I agree with Ginx about the 162.3 sustained for 19 mins being suspect. I think there could have been a malfunction at some point.

[Rjay]

i added the image above 162.3 sustained for 19 straight mins, I suspect this anemometer had technical issues.

Yea I saw you added that so I made the above post.

[Ginx snewx]

I agree with Ginx about the 162.3 sustained for 19 mins being suspect. I think there could have been a malfunction at some point.

I can't say anything about that station as there is no technical data on it but we shall hear eventually about the validity, strikes me as suspect at this time.

[Ground Scouring]

these are from Fb,the motel Josh was in, doesn't look Cat 5 ish

The middle image looks quite similar to the damage that some areas sustained in Haiyan. In both cases the coconut palms often retained their fronds while other vegetation was violently shredded nearby. I'm not saying that this was as intense as Haiyan was, but I would hesitate to make judgments one way or another. Vegetative damage is notoriously subjective and dependent on variables such as density, hardwood vs. softwood, depth of roots, soil type, etc. The surrounding area looks hilly, and in a compact but weakening system, the circulation was likely producing very intense winds just above the standard 10-m elevation. Terrain would have further enhanced such winds.

So even if the system was below Category 5 status at landfall, sustained winds just above 10 m likely still retained 140+ kt. A conversion to 10 m would likely still yield 125-135 kt (if not 140 kt) at landfall, meaning a storm at least as strong as Madeline 1976 (125 kt), which is the strongest eastern Pacific landfall on record. I also think that the pressure reports from both iCyclone and the biological station support a landfall value pretty close to the preliminary NHC estimate of 920 mb, given both sites' inland locations, the brief lull (far from a true calm) at each site, and the small size of the RMW. An application of the Schloemer (1954) equation actually yields 918 mb at landfall based on the 948 mb (27.98") peripheral sea-level reading from the biological station.

 

Do you think that the entire hour plus that station recorded Cat 5 winds is accurate? With the forward speed and size that seems highly unreliable. Josh estimated a 20 minute period of  high intensity, damage pictures do not represent winds of that magnitude. plus the 162.3 sustained for 19 mins is a huge red flag I am suspect.

Keep in mind that the system was moving rather quickly at landfall, so, given the compact size, areas at or inside the RMW would have only experienced the most extreme conditions for a very brief period. (To be honest, based on the data that have come out, I think that my initial landfall estimate of 115-120 kt is substantially too low, even if Patricia was just short of 140 kt as it hit.)

[Fergal]

Here are two charts of sustained and gusts from that station. The link is here

 

I am very suspicious of the report as it is at the base of a very peculiar spike (gust of 1138 mph anyone?). The question arises, where do the reliable data stop and the crazy start? 

 

Sustained (mph)

 

Gusts (mph)

 

Pressure (hPa)

 

 

[Ginx snewx]

The middle image looks quite similar to the damage that some areas sustained in Haiyan. In both cases the coconut palms often retained their fronds while other vegetation was violently shredded nearby. I'm not saying that this was as intense as Haiyan was, but I would hesitate to make judgments one way or another. Vegetative damage is notoriously subjective and dependent on variables such as density, hardwood vs. softwood, depth of roots, soil type, etc. The surrounding area looks hilly, and in a compact but weakening system, the circulation was likely producing very intense winds just above the standard 10-m elevation. Terrain would have further enhanced such winds.

So even if the system was below Category 5 status at landfall, sustained winds just above 10 m likely still retained 140+ kt. A conversion to 10 m would likely still yield 125-135 kt (if not 140 kt) at landfall, meaning a storm at least as strong as Madeline 1976 (125 kt), which is the strongest eastern Pacific landfall on record. I also think that the pressure reports from both iCyclone and the biological station support a landfall value pretty close to the preliminary NHC estimate of 920 mb, given both sites' inland locations, the brief lull (far from a true calm) at each site, and the small size of the RMW. An application of the Schloemer (1954) equation actually yields 918 mb at landfall based on the 948 mb (27.98") peripheral sea-level reading from the biological station.

 

Keep in mind that the system was moving rather quickly at landfall, so, given the compact size, areas at or inside the RMW would have only experienced the most extreme conditions for a very brief period. (To be honest, based on the data that have come out, I think that my initial landfall estimate of 115-120 kt is substantially too low, even if Patricia was just short of 140 kt as it hit.)

Is it possible that brief spin ups could account for the worst damage. I look at damage from Hurricane David and see total baring of hills and extreme damage. I would like to see aerial views to verify high cat 4 low 5, not saying it wasn't fierce. The bold confirming the wind data is probably suspect

[OSUmetstud]

For example, hurricane fabian hit Bermuda with at 100 kt (1 min mean) but cable and wireless at 280 ft asl recorded a 105 kt 10 minute mean. (This corresponds to about 120 kt 1 min mean).

[Ground Scouring]

 

Here's the first view I've found of Costa Careyes, apparently taken just after the peak winds arrived. The image appears to show extreme shredding of coconut palms in the background, with similar decapitation of several royal palms on the right. Apparently the concrete structures in the resort village survived the storm, but vegetative damage is extreme.

[ncforecaster89]

GS...those are some fairly large assumptions you made in the above posts. Case in point, the damage you referenced in the pics doesn't look remotely similar to the Haiyan photos. Moreover, I've personally seen similar damage (first-hand) to coconut palms following category-three winds...so that's not a reliable judgement not indicator of intensity, either.

EDIT: If it weren't for that one station reporting such extraordinary winds, I doubt (although I could be wrong) you'd changed the initial call you made at landfall. That's the only evidence one can really point to in support of retaining category-five at landfall...even though it appears clear to me those readings are very suspect.

[ncforecaster89]

For all the reasons both Ginx and I noted is why I feel fairly confident the wind data measured at the aforementioned site is inaccurate and not representative of the true landfalling intensity.

Objectively, look at all the atypical assumptions one has to make in an attempt to account for those wind readings as well as Patricia retaining category-five intensity at landfall.

One thing I'm most certain of is that there's virtually no chance that the operational landfalling central pressure is accurate and was very likely closer to 930 mb.

[Ground Scouring]

GS...those are some fairly large assumptions you made in the above posts. Case in point, the damage you referenced in the pics doesn't look remotely similar to the Haiyan photos. Moreover, I've personally seen similar damage (first-hand) to coconut palms following category-three winds...so that's not a reliable judgement not indicator of intensity, either.

 

 

For all the reasons both Ginx and I noted is why I feel fairly confident the wind data measured at the aforementioned site is inaccurate and not representative of the true landfalling intensity.

Objectively, look at all the atypical assumptions one has to make in an attempt to account for those wind readings as well as Patricia retaining category-five intensity at landfall.

One thing I'm most certain of is that there's virtually no chance that the operational landfalling central pressure is accurate and was very likely closer to 930 mb.

The Haiyan images that I've seen mostly showed coconut palms uprooted or snapped, but with their fronds intact, with some spotty exceptions. I could have missed other images and descriptions, of course, so I could very well be wrong. But as far as intensity is concerned, Josh explicitly said that the pressure would likely have been around 930 mb at landfall if the landfall location (~2 nm to his west) was correct. Given the extreme pressure gradient that he also mentioned, even a slight difference in the landfall location could mean a pressure 5-10 mb lower. (See wxmx's posts.) In his discussion with Dr. Postel, both seemingly agreed that Patricia will keep its Category-5 status at landfall when post-analysis is completed.

Now, that does not mean that Patricia actually was a Category 5 at landfall, but if not, it was almost certainly fairly close (within 10 kt or so). As for the anemometer, the initial 161-kt reading could have been accurate; the real anomalies indicating malfunction may have occurred just afterward, with the 141 kt for 19 consecutive minutes. Of course, given surrounding terrain, even if the 161-kt reading were accurate, whether it is representative of the storm's strength is another matter. There are good, scientific, meteorological cases for and against Patricia's maintaining at least 140 kt at landfall. Personally, I would go with 125-135 kt at landfall, but 140 kt is quite plausible, in my opinion.

[ncforecaster89]

So even if the system was below Category 5 status at landfall, sustained winds just above 10 m likely still retained 140+ kt. A conversion to 10 m would likely still yield 125-135 kt (if not 140 kt) at landfall, meaning a storm at least as strong as Madeline 1976 (125 kt), which is the strongest eastern Pacific landfall on record. I also think that the pressure reports from both iCyclone and the biological station support a landfall value pretty close to the preliminary NHC estimate of 920 mb, given both sites' inland locations, the brief lull (far from a true calm) at each site, and the small size of the RMW. An application of the Schloemer (1954) equation actually yields 918 mb at landfall based on the 948 mb (27.98") peripheral sea-level reading from the biological station.

Keep in mind that the system was moving rather quickly at landfall, so, given the compact size, areas at or inside the RMW would have only experienced the most extreme conditions for a very brief period. (To be honest, based on the data that have come out, I think that my initial landfall estimate of 115-120 kt is substantially too low, even if Patricia was just short of 140 kt as it hit.)

There are quite a few contradictory assumptions made in this post to derive at a possible 140 kt./920 mb category-five intensity.

One, it only matters what the estimated 1-minute maximum sustained winds are at 10 m. Secondly, the two pressure readings you mentioned are a significant basis for discounting the operational 920 mb estimate as being much too low. If there was a "true calm" at Josh's location (just a couple miles inland), then his 937 mb measurement would've been pretty close to the landfalling pressure-since it was moving at a fairly brisk translational speed. So, the quicker forward motion you noted is actually contradictory to your argument. Thirdly, you claim that the faster translational speed could be supportive of the biological station reporting category-five MSWs for an hour (roughly 10 nm NW of the geometric center no less), but then emphasize how these supposed category-five wind speeds would've only lasted "a brief period."

In all of those assumptions, you are ignoring a very significant factor involved here (which is common amongst those arguing for retention of category-five intensity)..the rapid weakening of the storm. There's a huge difference between Patricia coming ashore as a steady-state or strengthening hurricane, and one that was actually rapidly weakening at landfall. That is the main reason the wind-pressure relationship you mentioned most certainly isn't applicable here.

Not to mention, a small TC will continue to weaken at a much faster rate than one that is much larger. In addition, a hurricane weakening at landfall will also have more difficulty transporting the higher sustained winds to the surface...which is often times why you will get a larger wind gust to sustained wind ratio (irrespective of the frictional effects from land that will cause the same thing). This is another reason why you will see pockets of more extreme damage that isn't representative of the associated MSW attributed to the storm.

[ncforecaster89]

In his discussion with Dr. Postel, both seemingly agreed that Patricia will keep its Category-5 status at landfall when post-analysis is completed.

Now, that does not mean that Patricia actually was a Category 5 at landfall, but if not, it was almost certainly fairly close (within 10 kt or so).

There are good, scientific, meteorological cases for and against Patricia's maintaining at least 140 kt at landfall. Personally, I would go with 125-135 kt at landfall, but 140 kt is quite plausible, in my opinion.

I agree with this portion of your post. I too suspect the NHC will likely retain the current category-five designation, whether it's actually merited or not. For all the scientific reasons and the corresponding data consistently discussed here, I feel 140 kt. is just a little too high and agree with the idea of a 125-135 kt. high-end category-four landfalling intensity with a pressure around 930 mb.

I should add that I feel I owe you an apology for my initial couple of posts in response to your own in that I feel as though I came acrossed unjustly too combatively after rereading those posts. No excuse, but I haven't slept much the past few days and it's starting to catch up with me.

[ncforecaster89]

Here are two charts of sustained and gusts from that station. The link is here

I am very suspicious of the report as it is at the base of a very peculiar spike (gust of 1138 mph anyone?). The question arises, where do the reliable data stop and the crazy start?

Sustained (mph)

sustained.JPG

Gusts (mph)

gusts.JPG

Pressure (hPa)

pressure.JPG

Exactly! That's why I can't see how anyone can objectively find those observations credible...but that's just me.

[vortex95]

There are quite a few contradictory assumptions made in this post to derive at a possible 140 kt./920 mb category-five intensity.

One, it only matters what the estimated 1-minute maximum sustained winds are at 10 m. Secondly, the two pressure readings you mentioned are a significant basis for discounting the operational 920 mb estimate as being much too low. If there was a "true calm" at Josh's location (just a couple miles inland), then his 937 mb measurement would've been pretty close to the landfalling pressure-since it was moving at a fairly brisk translational speed. So, the quicker forward motion you noted is actually contradictory to your argument. Thirdly, you claim that the faster translational speed could be supportive of the biological station reporting category-five MSWs for an hour (roughly 10 nm NW of the geometric center no less), but then emphasize how these supposed category-five wind speeds would've only lasted "a brief period."

In all of those assumptions, you are ignoring a very significant factor involved here (which is common amongst those arguing for retention of category-five intensity)..the rapid weakening of the storm. There's a huge difference between Patricia coming ashore as a steady-state or strengthening hurricane, and one that was actually rapidly weakening at landfall. That is the main reason the wind-pressure relationship you mentioned most certainly isn't applicable here.

Not to mention, a small TC will continue to weaken at a much faster rate than one that is much larger. In addition, a hurricane weakening at landfall will also have more difficulty transporting the higher sustained winds to the surface...which is often times why you will get a larger wind gust to sustained wind ratio (irrespective of the frictional effects from land that will cause the same thing). This is another reason why you will see pockets of more extreme damage that isn't representative of the associated MSW attributed to the storm.

 

Excellent point about difference between an intensifying or steady-state hurricane at landfall vs. a weakening one.  That

makes a huge difference in sfc sustained winds.  Look at Katrina...920 mb pressure but only 125 mph at landfall, yet

Charley was "only" 941 mb at landfall but winds were 150 mph!  It is all about gradient and tightness of the inner core,

not absolute pressure values.  Perhaps the most amazing example of extreme winds and higher pressure was Felix from

2007,  929 mb but winds were 175 mph!   You simply can't use eye central pressure without looking at the storms inner

core structure and its intensity trend.   I don't care how intense a hurricane gets, the inner core can unravel/fall apart

very quickly, especially if it is small.  Conditions to support a 200 mph sustained wind inner core have to be absolutely perfect,

so any one of several things becoming less favorable, it's going to feel it.  In Patricia's case, I believe we had lower OHCs

near the coast, increasing shear, and a bit of dry air wrapping in (subsidence from the downslope flow wrapping from the

mountains inland into the storm's SE quadrant).  And much of western Mexico is an arid climate, far from say Florida or

the Yucatan.

[ncforecaster89]

Excellent point about difference between an intensifying or steady-state hurricane at landfall vs. a weakening one. That

makes a huge difference in sfc sustained winds. Look at Katrina...920 mb pressure but only 125 mph at landfall, yet

Charley was "only" 941 mb at landfall but winds were 150 mph! It is all about gradient and tightness of the inner core,

not absolute pressure values. Perhaps the most amazing example of extreme winds and higher pressure was Felix from

2007, 929 mb but winds were 175 mph! You simply can't use eye central pressure without looking at the storms inner

core structure and its intensity trend. I don't care how intense a hurricane gets, the inner core can unravel/fall apart

very quickly, especially if it is small. Conditions to support a 200 mph sustained wind inner core have to be absolutely perfect,

so any one of several things becoming less favorable, it's going to feel it. In Patricia's case, I believe we had lower OHCs

near the coast, increasing shear, and a bit of dry air wrapping in (subsidence from the downslope flow wrapping from the

mountains inland into the storm's SE quadrant). And much of western Mexico is an arid climate, far from say Florida or

the Yucatan.

I concur with every point you made in this post. Very well said!

[wxmx]

Anything from Sinaloa south in the Western coast it's actually a far cry from arid, actually very close to the Yucatan.