Hurricane Patricia; My Post-storm Analysis:

[ncforecaster89]

Hi everyone. This particular thread will focus on my own best educated guess/analysis regarding the landfall intensity of hurricane Patricia, and constitutes the thread I had promised to make, in the last post I made at 842 pm on 11/17/15, in the original Patricia thread.

As time permits, I will outline the various unbiased and objective scientific reasonings as to why I believe all of the available evidence strongly supports the conclusion that hurricane Patricia had weakened below category-five intensity, by the time it made landfall along the coast of SW MX.

[ncforecaster89]

PRESSURE GRADIENT DISCUSSION:

At one point, hurricane Patricia no doubt exhibited one of the most intense pressure gradients ever recorded (roughly six hours preceding landfall), at its peak intensity.

However, hurricane Patricia subsequently underwent an astonishing rate of weakening, during the last 5.75 hours prior to landfall, as the eye rapidly filled and the eyewall deteriorated. By the time Patricia was coming ashore, the eyewall appears to have been collapsing. Regardless, all available evidence (to include important obs taken by Josh M. and at the biological station) suggests Patricia still maintained a strong PG...as would be expected with a small category-four landfalling hurricane.

As mentioned in the other thread, the hurricane Andrew pressure-gradient I noted therein, was based solely on the PG observed between two separate locations. Consequently, one would be mistaken to make an apples to apples comparison between the suppossed 11 mb/nm PG theorized by Josh and the incredible 10 mb/nm PG observed between two fixed localities during the 145 kt. Cat 5 hurricane Andrew.

The PG assumed from the landfall point in Punta Gorda, Fl. and the observation taken at the Punta Gorda airport (3 nm E) was 7.7 mb/nm in the 125 kt. Cat 4 hurricane Charley, at its second U.S. landfall. These are actual PG's based on the lowest central pressure measured between two separate localities (within the inner-core at the same time), and aren't a presumed PG derived by extrapolation of the abrupt rise in the barometric pressure at a singular location for a rapidly weakening hurricane. In the latter case, one has to assume that there was no deviation of the respective isobars over a given distance, and based on a further assumed translational speed...all of which doesn't consider how much the rapid weakening influenced the ascending pressure increase at the singular location.

To put this in its proper perspective, hurricane Patricia would have to have had a minimum central pressure very close to the operational NHC value (920 mb) to match the PG in hurricane Charley, at a comparable distance to Josh's intercept location. It would have to have been closer to 912 mb to match Andrew's.

Based on PG alone, the actual data suggests hurricane Patricia was no more intense than hurricane Charley at landfall (relative to MSW).

[winterymix]

When is the final report from NHC?

[Hoosier]

When is the final report from NHC?

 

 

Not soon enough.

[ncforecaster89]

Not soon enough.

I agree! That said, there's nothing wrong with analyzing the various data, objectively, to make an educated guess about its landfalling intensity. The truth of the matter is that the NHC final report will be more subjective than they'd generally like, due to the limited amount of in-situ data available.

[Sampson]

So you think this was a Cat 4?

[ncforecaster89]

Another thing I noticed (during this research) is the very limited amount of barometric pressure readings taken where the maximum pressure gradient would typically be observed. In most cases, this is located just at the edge of the eye and at the inner edge of the NE eyewall.

The two PG's I referenced were each taken within 3 nm of the eye or within 3 nm of the NE edge of the inner-eyewall. Based on this, and the data collected by Josh, it appears highly likely that Josh was within the max PG (and RMW) when the eyewall crossed his position. Given the incredibly well-defined and completely closed eyewalls of the two aforementioned analog storms that were rapidly intensifying at landfall, it would seem to stretch scientific credibility to assume that Patricia maintained a PG equal to either at its own landfall.

It will be interesting to see what other evidence may be available to the NHC to help them determine just how close the geometrical center of the eye actually came to Josh's intercept location. At this point, it's difficult to argue that the collapsing eye and deteriorating eyewall of a rapidly weakening 932-936 mb (?) hurricane would support category-five intensity. That said, I'm just hoping the NHC is able to discover any additional evidence that might help them ascertain Patricia's true landfall intensity...with as little subjectivity involved as possible.

For the conspiracy theorists out there, let me reiterate that the only personal "agenda" I have (so to speak) is to simply and objectively analyze all of the available evidence to determine Patricia's genuine intensity at landfall. Nothing more and nothing less. I have spent a lot of my free time doing just the same thing for other previous hurricanes in the HURDAT database.

Far more importantly, I hope each and every member here has had, and is having, a wonderful Thanksgiving holiday!

[ncforecaster89]

So you think this was a Cat 4?

Most definitely...by the time it actually crossed the shoreline.

[ncforecaster89]

When is the final report from NHC?

Unfortunately, but understandably, the report won't likely be completed before mid January at the earliest. This guess is simply based on the typical time frame of when other previous significant hurricane events had their own reports released to the public...some as late as mid February, if I remember correctly.

Edit: I went back and saw that the Katrina report was released in late December, Charley's in late October, Ike's in mid January, and Sandy's in mid February. Based on this, it appears two months from the landfall date is generally the earliest we might expect Patricia's TCR to be completed. Of course, this is just a guess.