Cat 5 Major Hurricane Patricia

[ncforecaster89]

The report draws 5 major conclusions, which are conveniently outlined at the beginning. Two of them: 1) we were definitely in the eye and 2) the pressure gradient in PATRICIA’s inner core was nuclear—apparently over 11 mb/n mi in one place! (That’s just insane.) 

 

I just had enough time (before I head off to work for the next 12 hours) to very briefly skim over your chase repot.  As usual, it was very well written.  However, I did notice a mathematical error in the pressure gradient calculations contained therein.  To be specific, you used a quotient consisting of 5 minutes equals 1 nm...which isn't equivalent to 12 kt. (13 mph).  The same problem exists when you used the secondary figure of 13 kt. (15 mph) to come up with 1.08 miles per 5 minute interval for those equations.  

 

Not sure why you even used 12 kt. (13 mph) in the first place given that the translation speed was listed as 14 mph by the NHC at the 615 CDT advisory update and then 15 mph at the subsequent 7 pm CDT advisory.  Given that the forward speed is always averaged out over a period of generally 3 hours and Patricia was continuing to increase in forward speed...even the NHC advisory translational speeds were likely slower than those listed (especially in much shorter durations).  By their 10 pm CDT advisory, they had Patricia accelerating at a rate exceeding 20 mph.   Given all these factors, the absolute minimum distance Patricia covered at the time of your steepest pressure gradient would be no less than 15 mph (1.25 nm/5 min.)

 

This doesn't change the fact that you no doubt observed a very extreme PG, but that simply the calculations listed in your report aren't entirely accurate.  

 

As I suggested in previous posts, it seemed pretty apparent that you did get inside the eye...based on your obs and personal description of the conditions at that specific time. 

[ncforecaster89]

I was reading the posts on this thread as the storm was making landfall. You were one of two people declaring the storm to be a "category 4" while the sustained winds at the time were reported to be ~185 mph.

Perhaps the real question is why it's so important to you that it gets downgraded? The strongest winds did not extend far from the center. We've known this the entire time. The NHC and Josh (who was there) both agree that the storm was Cat 5 intensity. Who are you to argue?

First, you are incorrect in your recollection for I never said it was likely a high-end category-four until right at landfall. Regardless, my personal opinion was, and is, based on the data available both then and now. At the time I first suggested it may have weakened below category-five intensity, it was well after RECON had already measured a 31 mb increase in the central pressure in a 3 hour period (2.75 hours prior to landfall). The significant degradation of the satellite appearance and the obvious fact that the eye was continuing to fill at a very rapid pace, made it conceivable (if not likely) that Patricia had weakened below category-five intensity at landfall.

The answer to your other question is that my best educated guess is just as valid as Josh's, as we both have access to the same evidence by which to form an opinion. This may seem difficult for you to understand, but I just simply care about the absolute accuracy of the HURDAT record. As a result, I have assisted HRD in identifying various errors contained therein over the years. Hope this helps answer the question regarding my supposed motives. If it was the other way around and the evidence suggested to me that it was a category-five landfall, when they were calling it a category-four, I'd be doing the exact same thing. Keep in mind, it wasn't I that suggested those with a desenting opinion should not post any further.

P.S. I have to leave for work, and will not have time to reply to any further responses (to my own posts) until likely sometime tomorrow. That said, I sincerely wish you and everyone else a great rest of the day!

[Morris]

Hey, folks! My chase report is for Hurricane PATRICIA is complete!

Go to this page and click the Chase Report button: http://icyclone.com/chases/patricia-2015.html

Because of 1) the great stature of PATRICIA (the strongest landfalling hurricane in the history of the Eastern Pacific), 2) our fortunate location right at the landfall point, and 3) the lack of other data and observations from the inner core, I spent extra time on this report. I’m hoping it will really help the National Hurricane Center with their postanalysis work on PATRICIA.

The report draws 5 major conclusions, which are conveniently outlined at the beginning. Two of them: 1) we were definitely in the eye and 2) the pressure gradient in PATRICIA’s inner core was nuclear—apparently over 11 mb/n mi in one place! (That’s just insane.) The report is loaded with damage pictures for folks who are less technical.

Finally, the report draws no conclusions Re: wind speeds or intensity. I am aware one or two folks here believe it was a Cat 4. This viewpoint need not be reiterated. Your feelings are clear.

Video coming next!

Amazing job! Thanks! I just finished reading it

[HurricaneJosh]

Why is it so important to you that Patricia be kept at its current category-five designation? Why does it appear to be somewhat offensive to you that anyone else might honestly believe it had weakened to a high-end category-four hurricane at landfall? I just don't understand why an honest and respectful debate has to be taken so personally.

As I mentioned in my previous post, I believe you should be most thankful it wasn't at category-five intensity at landfall...for there's a real possibility you might not have survived to tell about it. For me, your safety, and that of all others in harms way, were far more important.

I'm sorry if my completely unbiased and objective review of the available data may differ from your own (or that of anyone else here), but my own personal opinion, and best educated guess, is no less valid than your own.

That said, I will give a more thorough and detailed explanation of my reasoning as to why it appears highly likely Patricia didn't retain category-five intensity at landfall, as time permits.

 

I don't understand your post. I said above that the storm may be downgraded and I will live by whatever the NHC says. I haven't argued for one classification or another. Are you thinking of someone else?

[HurricaneJosh]

I just had enough time (before I head off to work for the next 12 hours) to very briefly skim over your chase repot.  As usual, it was very well written.  However, I did notice a mathematical error in the pressure gradient calculations contained therein.  To be specific, you used a quotient consisting of 5 minutes equals 1 nm...which isn't equivalent to 12 kt. (13 mph).  The same problem exists when you used the secondary figure of 13 kt. (15 mph) to come up with 1.08 miles per 5 minute interval for those equations.  

 

Not sure why you even used 12 kt. (13 mph) in the first place given that the translation speed was listed as 14 mph by the NHC at the 615 CDT advisory update and then 15 mph at the subsequent 7 pm CDT advisory.  Given that the forward speed is always averaged out over a period of generally 3 hours and Patricia was continuing to increase in forward speed...even the NHC advisory translational speeds were likely slower than those listed (especially in much shorter durations).  By their 10 pm CDT advisory, they had Patricia accelerating at a rate exceeding 20 mph.   Given all these factors, the absolute minimum distance Patricia covered at the time of your steepest pressure gradient would be no less than 15 mph (1.25 nm/5 min.)

 

This doesn't change the fact that you no doubt observed a very extreme PG, but that simply the calculations listed in your report aren't entirely accurate.  

 

As I suggested in previous posts, it seemed pretty apparent that you did get inside the eye...based on your obs and personal description of the conditions at that specific time. 

 

Huh?12 kt is what they said in the 4 pm package (read the Discussion and Forecast Advisory).12 kt =13.8 mph which rounds to 14 mph-- which is what they used in the public advisories at 4 pm and 6:30 pm. So obviously the NHC feels 12 kt = 14 mph, since they used these two values at the same time (4 pm).

 

You suggested I should have used 15 mph in my calculations. I did. I did calculations for 12 kt and 13 kt. 13 kt = 14.95 mph, which rounds to 15 mph.

 

I don't mind discussing the report, but I do have concerns with you skimming it and then suggesting it has errors where it doesn't. And it especially concerns me that, in "correcting" the report, you write things that are factually incorrect. 12 kt is not 13 mph. It rounds to 14 mph, as per the NHC.

[winterymix]

Josh,

 

Those of us that have known you a long time realize that you adhere to scientific integrity

and that speaks for itself.

[shaggy]

Huh?12 kt is what they said in the 4 pm package (read the Discussion and Forecast Advisory).12 kt =13.8 mph which rounds to 14 mph-- which is what they used in the public advisories at 4 pm and 6:30 pm. So obviously the NHC feels 12 kt = 14 mph, since they used these two values at the same time (4 pm).

You suggested I should have used 15 mph in my calculations. I did. I did calculations for 12 kt and 13 kt. 13 kt = 14.95 mph, which rounds to 15 mph.

I don't mind discussing the report, but I do have concerns with you skimming it and then suggesting it has errors where it doesn't. And it especially concerns me that, in "correcting" the report, you write things that are factually incorrect. 12 kt is not 13 mph. It rounds to 14 mph, as per the NHC.

Regardless of the nitpicking you've had an epic chase season Josh. Continue to chase safe and report back the facts as you have them and just be glad you get to do what you.

[ncforecaster89]

 

 

Huh?12 kt is what they said in the 4 pm package (read the Discussion and Forecast Advisory).12 kt =13.8 mph which rounds to 14 mph-- which is what they used in the public advisories at 4 pm and 6:30 pm. So obviously the NHC feels 12 kt = 14 mph, since they used these two values at the same time (4 pm).

 

You suggested I should have used 15 mph in my calculations. I did. I did calculations for 12 kt and 13 kt. 13 kt = 14.95 mph, which rounds to 15 mph.

 

I don't mind discussing the report, but I do have concerns with you skimming it and then suggesting it has errors where it doesn't. And it especially concerns me that, in "correcting" the report, you write things that are factually incorrect. 12 kt is not 13 mph. It rounds to 14 mph, as per the NHC.

 

 

 

Hey Josh.  I will always be the first to admit when I make a mistake and I did just that in stating 12 kt equals 13 mph...which is incorrect (rounds to 14 mph).  That said, my main point remains.  See  below:

 

"As per NHC advisories, PATRICIA was accelerating from 12 to 13 kt during its passage through Emiliano Zapata, Therefore, I calculated gradients using forward speeds of 12 and 13 kt:

• For a forward speed of 12 kt, I assumed my fixed location sampled 1 n mi of the cyclone every 5 minutes.

• For a forward speed of 13 kt, I assumed my fixed location sampled 1.08 n mi of the cyclone ever 5 minutes." 

These calculations are inaccurate (If my math is correct), as I noted in my previous post:  

 

12 kt. = 14 mph.  Therefore, 14/12 = 1.17 nm every 5 minutes (not 1.0 nm used in your calculation). 

13 kt. = 15 mph.  Therefore, 15/12 = 1.25 nm every 5 minutes (not 1.08 nm).

 

In both cases, you used the specific number listed in knots without converting it into miles per hour.  That's why i was saying those calculations aren't mathematically correct.  Consequently, all of the pressure gradient calculations listed in your report are off, accordingly...without taking any of the other factors into consideration.

[bdgwx]

Great report Josh! It'll take me some time to go through all of that.

 

We now have coordinates of the only two pressure readings.

 

Josh: 19.38973, -104.96391

CCXJ1:19.49833, -105.04472 

 

The distance between these points is 14.75km, 9.17m, or 7.97nm.

[HurricaneJosh]

Hey Josh.  I will always be the first to admit when I make a mistake and I did just that in stating 12 kt equals 13 mph...which is incorrect (rounds to 14 mph).  That said, my main point remains.  See  below:

 

"As per NHC advisories, PATRICIA was accelerating from 12 to 13 kt during its passage through Emiliano Zapata, Therefore, I calculated gradients using forward speeds of 12 and 13 kt:

• For a forward speed of 12 kt, I assumed my fixed location sampled 1 n mi of the cyclone every 5 minutes.

• For a forward speed of 13 kt, I assumed my fixed location sampled 1.08 n mi of the cyclone ever 5 minutes." 

These calculations are inaccurate (If my math is correct), as I noted in my previous post:  

 

12 kt. = 14 mph.  Therefore, 14/12 = 1.17 nm every 5 minutes (not 1.0 nm used in your calculation). 

13 kt. = 15 mph.  Therefore, 15/12 = 1.25 nm every 5 minutes (not 1.08 nm).

 

In both cases, you used the specific number listed in knots without converting it into miles per hour.  That's why i was saying those calculations aren't mathematically correct.  Consequently, all of the pressure gradient calculations listed in your report are off, accordingly...without taking any of the other factors into consideration.

 

Tony, I am not using miles or mph in any calculations. I am using only nautical miles and knots (which is nautical miles per hour). Statute miles have zero to do with my work.

[wxmx]

Hey Josh.  I will always be the first to admit when I make a mistake and I did just that in stating 12 kt equals 13 mph...which is incorrect (rounds to 14 mph).  That said, my main point remains.  See  below:

 

"As per NHC advisories, PATRICIA was accelerating from 12 to 13 kt during its passage through Emiliano Zapata, Therefore, I calculated gradients using forward speeds of 12 and 13 kt:

• For a forward speed of 12 kt, I assumed my fixed location sampled 1 n mi of the cyclone every 5 minutes.

• For a forward speed of 13 kt, I assumed my fixed location sampled 1.08 n mi of the cyclone ever 5 minutes." 

These calculations are inaccurate (If my math is correct), as I noted in my previous post:  

 

12 kt. = 14 mph.  Therefore, 14/12 = 1.17 nm every 5 minutes (not 1.0 nm used in your calculation). 

13 kt. = 15 mph.  Therefore, 15/12 = 1.25 nm every 5 minutes (not 1.08 nm).

 

In both cases, you used the specific number listed in knots without converting it into miles per hour.  That's why i was saying those calculations aren't mathematically correct.  Consequently, all of the pressure gradient calculations listed in your report are off, accordingly...without taking any of the other factors into consideration.

The knot (/nɒt/) is a unit of speed equal to one nautical mile (1.852 km) per hour. No need to convert anything.

[Mallow]

Hey Josh.  I will always be the first to admit when I make a mistake and I did just that in stating 12 kt equals 13 mph...which is incorrect (rounds to 14 mph).  That said, my main point remains.  See  below:

 

"As per NHC advisories, PATRICIA was accelerating from 12 to 13 kt during its passage through Emiliano Zapata, Therefore, I calculated gradients using forward speeds of 12 and 13 kt:

• For a forward speed of 12 kt, I assumed my fixed location sampled 1 n mi of the cyclone every 5 minutes.

• For a forward speed of 13 kt, I assumed my fixed location sampled 1.08 n mi of the cyclone ever 5 minutes." 

These calculations are inaccurate (If my math is correct), as I noted in my previous post:  

 

12 kt. = 14 mph.  Therefore, 14/12 = 1.17 nm every 5 minutes (not 1.0 nm used in your calculation). 

13 kt. = 15 mph.  Therefore, 15/12 = 1.25 nm every 5 minutes (not 1.08 nm).

 

In both cases, you used the specific number listed in knots without converting it into miles per hour.  That's why i was saying those calculations aren't mathematically correct.  Consequently, all of the pressure gradient calculations listed in your report are off, accordingly...without taking any of the other factors into consideration.

 

1kt = 1 nautical mile per hour.

 

EDIT:

Tony, I am not using miles or mph in any calculations. I am using only nautical miles and knots (which is nautical miles per hour). Statute miles have zero to do with my work.

The knot (/nɒt/) is a unit of speed equal to one nautical mile (1.852 km) per hour. No need to convert anything.

 

[ncforecaster89]

Regardless of the nitpicking you've had an epic chase season Josh. Continue to chase safe and report back the facts as you have them and just be glad you get to do what you.

 

I agree with everything you stated here, for the most part.  However, it's not "nitpicking" to point out errors in data calculations (just as he rightfully corrected me when I wrongly stated 12 knots equals 13 mph), when one is suggesting the NHC use their report in its reanalysis.  

 

As time permits, I will provide a much clearer and more detailed summary as to why I feel all of the data currently available  strongly indicates that Patricia weakened below category-five intensity prior to crossing the coast.  Reanalysis is all about "nitpicking" and thoroughly examining all available evidence to come to the most accurate conclusions.  That's what science is all about.

[ncforecaster89]

The knot (/nɒt/) is a unit of speed equal to one nautical mile (1.852 km) per hour. No need to convert anything.

 

You're all correct on that point.  I was erroneously thinking in terms of statue miles, and should have known better!  That's what sleep deprivation will do to you.

[ncforecaster89]

Tony, I am not using miles or mph in any calculations. I am using only nautical miles and knots (which is nautical miles per hour). Statute miles have zero to do with my work.

 

Yep.  My mistake and I sincerely apologize for not catching my own error in that regard.    

[H2O]

Well that's two things erroneously nitpicked in the last few posts.  Someone has an agenda

[HurricaneJosh]

Yep.  My mistake and I sincerely apologize for not catching my own error in that regard.    

 

Thanks.

[ncforecaster89]

Well that's two things erroneously nitpicked in the last few posts.  Someone has an agenda

 

Uh, no! No agenda H20.  I stand by all of my previous points that are soundly based on all of the available data and evidence available to date.  I acknowledged my own error resulting from a brief skimming over Josh's report (due to time constraints) and impairment due to sleep deprivation.  Happens to the best of us.  You, on the other hand, wrongly made an unfounded accusation presented as fact...which is wholly inaccurate!  

[ncforecaster89]

Thanks.

 

 

You're welcome, Josh. I most certainly owed you that apology.  

 

Although we may interpret the available data/evidence somewhat differently, it doesn't affect my genuine appreciation for the job you did in obtaining the data you collected or the extreme intensity this particular hurricane contained when it hit the coast of SW Mexico.  

 

I presume (maybe incorrectly) that you might lean towards a 140 kt. category-five landfall intensity, whereby I interpret the data to correspond to a 130 kt. high-end category-four landfall.  In reality, there's not too much differential (10 kt.) in our respective interpretations of the available evidence, and we both agree that Patricia is very likely the most intense EPAC hurricane landfall in recorded history.  Another common characteristic we share is that we each care deeply about the integrity of the HURDAT record.  In this case, we appear to just simply disagree slightly on whether or not Patricia retained category-five strength upon landfall.  For us, as has been the case for the NHC best-track committee conducting HURDAT reanalysis, there is added scrutiny when reanalyzing category-four and category-five operationally derived intensities.          

[eekuasepinniW]

Why does someone with relentless verbal diarrhea always show up to obnoxiously dominate these storm threads? 

[ncforecaster89]

 

Why does someone with relentless verbal diarrhea always show up to obnoxiously dominate these storm threads? 

 

 

If you're referring to me, my own posts are typically in response to those responding to my own.  If you don't want to read my posts...don't reference me.  Thanks.

 

In contrast to your post, at least mine are actually focused on the topic being discussed, as opposed to making unnecessary personal attacks.

[HurricaneJosh]

You're welcome, Josh. I most certainly owed you that apology.  

 

Although we may interpret the available data/evidence somewhat differently, it doesn't affect my genuine appreciation for the job you did in obtaining the data you collected or the extreme intensity this particular hurricane contained when it hit the coast of SW Mexico.  

 

I presume (maybe incorrectly) that you might lean towards a 140 kt. category-five landfall intensity, whereby I interpret the data to correspond to a 130 kt. high-end category-four landfall.  In reality, there's not too much differential (10 kt.) in our respective interpretations of the available evidence, and we both agree that Patricia is very likely the most intense EPAC hurricane landfall in recorded history.  Another common characteristic we share is that we each care deeply about the integrity of the HURDAT record.  In this case, we appear to just simply disagree slightly on whether or not Patricia retained category-five strength upon landfall.  For us, as has been the case for the NHC best-track committee conducting HURDAT reanalysis, there is added scrutiny when reanalyzing category-four and category-five operationally derived intensities.          

 

Thanks. I haven't expressed an opinion about the landfall intensity either way.  I call it a Cat 5 now simply because that's what the NHC has called it operationally. As I've said, I think there are many factors at play, and many ways to look at it. The NHC can come back with anything from 130 to 145 kt and support the figure with reasonable arguments. Whatever their verdict is, that's how I'll refer to the storm in the future.

[bdgwx]

Here is a breakdown of how JOSH1 and CCXJ1 compare. An asterix is used to indicate that I interpolated a pressure value using a time-weighted mean between nearest neighbor samples to get JOSH1 and CCXJ1 time aligned.

 

        JOSH1  CCXJ1   JOSH-winds   CCXJ1-winds
16:30   989    988     
17:00   984    985     
17:30   973    979     damaging     42 / 103
17:40   965*   977     damaging     46 / 129
17:50   957    973     damaging     49 / 139
18:00   946    969     damaging     66 / 161
18:10   940    963     calm         89 / 211
18:15   938    960*    damaging
18:20   941*   956     damaging     104
18:30   947    951     violent      149
18:40   961*   947     violent      133
18:50   971    949     violent      185
19:00   978    953     damaging
19:10   982*   965     damaging
19:20   985    971     damaging
19:30   988    976     windy        162
19:40   990    981     windy        81
19:50   992*   984     windy        66 / 143
20:00   994    986     windy        76 / 149
20:30   998    992     
21:00  1001    995     

 

[Roger Smith]

Whatever, I imagine the good people of Emiliano Zapata will be hoping you don't show up a third time Josh, at least not to stay overnight. Awesome photo gallery in your report. The people at the nearby coastal Cuixmala resort might have some evidence to resolve the landfall intensity question, I wonder if the NHC would overfly the coast on a clear day and check the tree damage around that resort (their website just makes mention of a lot of local damage).

 

I notice in your time sequence of satellite images the intensity of echoes on the west side appeared to peak around the time that the biological station had its peak wind reports, and presumably when that nearby village of Chamela was badly damaged, so maybe there was a bit of embedded tornadic activity over on that side of the eye.

 

Hopefully the Mexican government will see fit to add a radar in Puerto Vallarta or maybe Emiliano Zapata since that seems to be their equivalent of Galveston. One thing I learned from this storm was the phenomenon of satellite parallax, it was noticeable all day that the NHC positions were 0.2 deg west of the apparent satellite locations, while at the correct latitude. Any qualified met, can you enlighten us as to whether this parallax phenomenon increases with distance from the equator? I think the direction of the parallax is determined by side of the image, is there an easy way to tell what longitude the satellite is located? I'm assuming that not all satellite images are directly below the satellite in question (or are they?).  

[HurricaneJosh]

 

Here is a breakdown of how JOSH1 and CCXJ1 compare. An asterix is used to indicate that I interpolated a pressure value using a time-weighted mean between nearest neighbor samples to get JOSH1 and CCXJ1 time aligned.

 

        JOSH1  CCXJ1   JOSH-winds   CCXJ1-winds
16:30   989    988     
17:00   984    985     
17:30   973    979     damaging     42 / 103
17:40   965*   977     damaging     46 / 129
17:50   957    973     damaging     49 / 139
18:00   946    969     damaging     66 / 161
18:10   940    963     calm         89 / 211
18:15   938    960*    damaging
18:20   941*   956     damaging     104
18:30   947    951     violent      149
18:40   961*   947     violent      133
18:50   971    949     violent      185
19:00   978    953     damaging
19:10   982*   965     damaging
19:20   985    971     damaging
19:30   988    976     windy        162
19:40   990    981     windy        81
19:50   992*   984     windy        66 / 143
20:00   994    986     windy        76 / 149
20:30   998    992     
21:00  1001    995     

 

 

Pretty cool! If you'd like, here are the missing actual values:

 

17:40: 965.4 mb

18:20: 941.6 mb

18:40: 956.9 mb

19:10: 981.9 mb

19:50: 992.4 mb

 

As you can see, most of your estimates were very close except 18:40, which was during a period of violent change.

 

Two quick things I want to emphasize:

• My times are CDT. Not sure if that station is CDT or CST, but just wanted to note that.
• My values are sea-level pressure. Not sure if that station's values are sea-level or station pressure.

I'm sure you're mindful of these things but just wanted to make sure.

[wxmx]

There's a radar in Cuyutlán, Colima...a bit down the coast of Manzanillo, and that radar would have been great during Patricia had it been functional. Currently only 8 out of 13 radars are working, usually they take a few months to make them operative after failure.

[bdgwx]

Pretty cool! If you'd like, here are the missing actual values:

 

17:40: 965.4 mb

18:20: 941.6 mb

18:40: 956.9 mb

19:10: 981.9 mb

19:50: 992.4 mb

 

As you can see, most of your estimates were very close except 18:40, which was during a period of violent change.

 

Two quick things I want to emphasize:

• My times are CDT. Not sure if that station is CDT or CST, but just wanted to note that.
• My values are sea-level pressure. Not sure if that station's values are sea-level or station pressure.

I'm sure you're mindful of these things but just wanted to make sure.

 

Sweet. Thanks Josh! I knew the time-weighted interpolation I was using near 18:40 wasn't correct, but I didn't know what else to do. That certainly clears things up.

• I believe the CCXJ1 station was reporting in CDT at the time.
• Actually the raw dump of CCXJ1 had station pressure. I adjusted all of the values by +10mb (using 100m height and 23C temperature) to reduce to sea level manually.

 

Here is the corrected table.

        JOSH1  CCXJ1   JOSH-winds   CCXJ1-winds
16:30   989    988     
17:00   984    985     
17:30   973    979     damaging     42 / 103
17:40   965    977     damaging     46 / 129
17:50   957    973     damaging     49 / 139
18:00   946    969     damaging     66 / 161
18:10   940    963     calm         89 / 211
18:15   938    960*    damaging
18:20   942    956     damaging     104
18:30   947    951     violent      149
18:40   957    947     violent      133
18:50   971    949     violent      185
19:00   978    953     damaging
19:10   982    965     damaging
19:20   985    971     damaging
19:30   988    976     windy        162
19:40   990    981     windy        81
19:50   992    984     windy        66 / 143
20:00   994    986     windy        76 / 149
20:30   998    992     
21:00  1001    995     

[bdgwx]

It is also important to note that Josh reported that the center could have been 2nm to the west of his location. That would place the center between JOSH1 and CCXJ1 but closer to JOSH1. So yes, the pressure at the center of the eye was likely much lower than the minimum reading observed at JOSH1.

 

For the experts...I envision (possibly incorrectly) that the laplacian of the pressure field is > 0 (positive) inside the eye at the center to the point where cyclostrophic balance is achieved and < 0 (negative) from this point outward to the environment. Is that correct? If that's the case then I don't think we can take ~10mb/nm (like what Hurricane Andrew was claimed to have had in it's eye wall) to extrapolate a minimum centeral pressure from the JOSH1 reading. However, we can easily get into the upper 920s by using a more modest (relatively speaking) 5mb/nm. The official NHC lanfalling pressure was 924mb right?

 

Edit: changed "eye" to "center" in the 1st paragraph to clarify meaning

[HurricaneJosh]

To be clear: the center was a little to my W, but I was in the eye. (Center and eye are not the same thing: the center is just a theoretical point (likely at exact midpoint of the eye), whereas the eye is a calm region that actually occupies space and distance.)

 

My report uses my minimum pressure reading at the edge of the eye to estimate a central-pressure range at landfall: 931-935 mb.

 

The NHC estimated the landfall pressure to be 920 mb operationally, but that was probably too low.

[clskinsfan]

Really a great report Josh. That gradient is unbelievable. I know you said in some previous statements that Patricia had some of the worst winds you have experienced. After having a little time to digest the storm and compare to your other chases. Do you still feel that way? The videos I have seen of yours from Haiyan are crazy thats why I ask.