Was Beryl Only A Cat 4?

By Paul Homewood

We’ve now got more data in for Hurricane Beryl, and as we have seen many times recently, it appears that the wind speeds have been grossly overestimated.

According to the official reports, Beryl has sustained winds of 165mph (145kts), and a minimum central pressure of 934mb.

But according to the official satellite Dvorak measurements, the wind speeds were well below the warning intensity, around 135kts. On the Saffir Simpson scale, Cat 5s are 137kts and over, so it seems that Beryl was probably a top end Cat 4:

http://rammb-data.cira.colostate.edu/tc_realtime/archive.asp?product=dgtldvor&storm_identifier=al022024

As usually happens nowadays, the National Hurricane Center tends to overestimate wind speeds, to be “on the safe side”. This may make sense from a public safety point of view, but unfortunately it is these warnings which appear in the media as “actual”.

http://rammb-data.cira.colostate.edu/tc_realtime/about.asp#strmstat

Further evidence that the windspeeds were overstated is provided by that central pressure of 934mb. In pre-satellite days, winds were estimated from air pressure.

The chart below plots windspeed against pressure for all Atlantic Cat 5s which had Beryl’s air pressure or below.

As you would expect, low pressure means high windspeed. Beryl, however, bucks the trend. Five other hurricanes have recorded 165 mph, but all have had much lower central pressure, ranging from 910 to 927mb. And a further six storms have had lower pressure, but only speeds of 160mph:

https://en.wikipedia.org/wiki/List_of_Category_5_Atlantic_hurricanes

Below are all of the 165mph ones:

Quite clearly the likes of Cuba, Hattie and Ivan were in a different league to Beryl. It is significant too that Matthew in 2016 has been overstated in exactly the same way as Beryl. This is plainly a new phenomena.

Aftermath of Hurricane Hattie 1961 – Belize

I should perhaps make it clear that I accept that modern measurements are the ones that are accurate. But if this is the case, all of the others that have gone before must be underestimated.

Just to finish, the following describes how Dvorak works:

I make no comment as to the accuracy or reliability of Dvorak.

	Year	mb
Cuba	1924	910
Hattie	1961	914
Inez	1966	927
Isabel	2003	915
Ivan	2004	910
Matthew	2016	934
Irma	2023	926
Beryl	2024	934