ncforecaster89 wrote:
As far as Dorian is concerned:
The data can legitimately be analyzed to suggest an intensity as high as 170 kt to as low as 145 kt...although it's highly likely the actual MSW was between those two extremes.
Curious as to others thoughts on whether the NHC modifies the operational peak intensity in the forthcoming TCR?
I'm putting my bets on retaining 160kts as peak and landfall. It was a historic landfall, matching the '35 Labor Day Hurricane, and if they had sufficient evidence to downgrade it, I think they would, but I don't think they do.
If you compare Irma and Dorian purely on flight level, it would make sense for them to nudge Dorian's intensity down to 150-155kts based on what they did with Irma, but Dorian has Irma beat by far in regards to SFMR and eyewall dropsondes.
1. Irma produced 2 SFMR readings at 160kts. That's it. All the rest were lower. I'm going off memory for this, I believe my full post is in the "Intense Tropical Cyclones" thread, but if memory serves correctly, Dorian produced 21 SFMR readings to support 170kts, 9 of them were flagged, 12 were unflagged. That's a lot more than Irma.
2. Dorian's eyewall dropsondes consistently showed stronger winds in the lower half of the storm as opposed to closer to the 700mb flight level, the dropsondes frequently suggested surface winds that would exceed the 700mb winds in my opinion. I believe the one dropsonde set a dropsonde record (for the Atlantic anyway) measuring 176kts at the surface (giving a bit more credibility to those SFMR readings, even if it is an instantaneous wind), and I think it was that same dropsonde that showed the strongest winds were confined to something like the lowest 30mb of the eyewall. I don't know a huge ton about eyewall dynamics as I'm not an expert nor am I studying meteorology as a student, but I have a theory that the top of the boundary layer may have been lower than what is typical, and that inflated the surface winds somewhat, just based off what the eyewall drops kept showing.
I know the NHC likes to blend with flight level and doesn't fully trust the SFMR, but I think 161kts flight level combined with a multitude of SFMR readings supporting 170kts will be enough for them to assume a 1:1 ratio between flight level and surface is logical and they'll keep the peak intensity at 160kts. I even think there's an outside chance at 165kts, but very unlikely.
What I'm actually most curious about is if they make him a Cat 5 sooner than they did operationally. I'm of the opinion (and many others were at the time too), that there was sufficient evidence to upgrade Dorian on the 31st. I think they've got data to support walking back the time he officially intensified to Cat 5, it's just a matter of waiting for their report to see if they do it. I'm split 50/50 on this. I can see them doing it, but I can also see them doubling down on their operational reasoning and keeping his initial Cat 5 point the same.