aspen wrote:I think there’s a decent possibility of Dorian’s peak being slightly increased, either with winds getting upped by 5-10 kt or the pressure being dropped a few mbar. It maintained 170+ kt SFMR measurements around its peak intensity and one pass recorded an extrapolated pressure of 907 mbar. I don’t think Dorian did get up to 170 kt, but 165 kt is more believable. However, there’s a chance it could also be downgraded to 155 kt like Irma. How did Dorian’s SFMR readings compare to Irma’s, and what justified its downgrade?
I think Dorian did get to 170kt. I understand that the NHC believes the SFMR might be running too hot, but when you compare the SFMR readings to the eyewall profiles shown by dropsonde, it makes sense to me that the SFMR winds would be higher than flight level. Dropsondes consistently showed the eyewall had stronger winds between 850mb down to the surface as compared to 850mb up to the 700mb flight level. There was also a wealth of SFMR readings supporting 170kt, it wasn't just a one-off reading.
Flagged readings: 172kt, 168kt, 176kt, 169kt, 172kt, 171kt, 172kt, 170kt, 176kt
Unflagged readings: 170kt, 176kt, 172kt, 168kt, 170kt, 177kt, 168kt, 166kt, 166kt, 167kt, 167kt, 166kt
That's 9 flagged readings and 12 unflagged readings for a total of 21 SFMR readings that support a 170kt intensity (in my opinion). Highest 10 second flight level wind was 161kts.
In comparison to Irma, her highest 10 second flight level wind was 171kts, and she had 2 SFMR readings at 160kt.
Despite Dorian not having the flight level winds to support a 170 kt intensity, I still think huge variations exist in eyewalls and a 10% reduction standard from 700mb just doesn't work for every storm. In my opinion, dropsondes in eyewalls have demonstrated the huge variety in eyewall structures and behaviors.
For example, the eyewall dropsonde that measured a 176kt gust at the surface:
Between 904mb to 939mb at the surface, every single reading was 170kts or greater. So, the lowest 35mb of the eyewall was entirely producing winds equal to or in excess of 170kts, with a peak wind of 195kts at 912mb, 27mb above the surface.
Now, between 751mb to 870mb, the highest wind reported was 161kts, with winds dipping as low at 124kts.
Now, dropsondes aren't completely reliable because they're essentially data tubes falling through the atmosphere and sometimes they get blown out of the eyewall and land in different regions, but Dorian pretty consistently showed the strongest wind energy being generated in the lower levels as measured by dropsonde.
I personally think Dorian beat Allen's sustained wind record, but I'm not expecting the NHC to up him that high.
