2023 TCR's

[ljmac75]

123 FL 116 SFMR justifies 115 knots well enough.

How reliable were the SFMR estimates do you think? My KZC relationship calculator is giving me around 110 kts, but of course pressure-wind relationships are finicky.

[DioBrando]

BREAKING NEWS: IDALIA IS UP (115KT/942MB)

https://www.nhc.noaa.gov/data/tcr/AL102023_Idalia.pdf

[MarioProtVI]

I fail to see how a possibly transient 115 kt SFMR is enough to support C4. FL>surface conversion worked way better and the fact NHC admits uncertainty in the landfall intensity (raising the possibility Idalia was never a major at landfall). No other data besides the one SFMR point supported C4, at best they supported 110 kt.

[DioBrando]

I fail to see how a possibly transient 115 kt SFMR is enough to support C4. FL>surface conversion worked way better and the fact NHC admits uncertainty in the landfall intensity (raising the possibility Idalia was never a major at landfall). No other data besides the one SFMR point supported C4, at best they supported 110 kt.

idk ask Humberto

[cycloneye]

The highest surge occured in unpopulated areas.

 https://twitter.com/NHC_Atlantic/status/1757421187812991143

[Hurricane2022]

Peak remained at 115 kt, pressure is now 942 mb
Landafall was at 100 kt
"Idalia rapidly intensified while it was over the Gulf of Mexico and reached an estimated
peak intensity of 115 kt (category 4 on the Saffir-Simpson Hurricane Wind Scale) at 0900 UTC 30
August (cover image). The estimated peak intensity is based on data collected by the Air Force
Reserve Hurricane Hunters between 0700 and 0900 UTC that day. The highest 700-mb flight-
level wind recorded was 123 kt, which adjusts to about 111 kt at the surface using a standard
reduction factor. The peak reliable SFMR wind was 116 kt around the same time. The minimum
pressure of 942 mb is based on dropsonde data and agrees well with the estimates from the
Knaff-Zehr-Courtney pressure-wind relationship."
https://www.nhc.noaa.gov/data/tcr/AL102023_Idalia.pdf

[cycloneye]

 https://twitter.com/iCyclone/status/1757508109428248728




 https://twitter.com/iCyclone/status/1757508710056755493

[CrazyC83]

I do agree that 100 kt might be a bit generous, although the area was not well sampled at landfall and the Recon didn't get a good picture of a storm that was filling quickly. The landfall pressure of 950 mb appears reasonable based on all the data, since it had likely filled some more up to the reading on land.

The official reporting site in Perry, Florida reported a minimum pressure of 957.7 mb at 1215 UTC 30 August. That station also reported a sustained wind of 54 kt at that time.

That would line up well with the measurements by Josh - the wind conversion would be 953 mb as a central pressure at that time. It's likely Josh was near the true center and the ASOS site was just outside of it.

As far as the peak intensity, I do also think that 116 kt SFMR reading should be thrown out as (a) transient, and (b) questionable over shallow water near shore. That was the only data point to support such an intensity - the pressure reading on its own was marginal, radar didn't support it and neither did the Dvorak reading of T5.5 at the time.

Going back to Hilary, I'm really not too sure about their analysis. Looking at the pressure readings show quite low pressures over the California coast, and those were clearly the lowest all the way through (lowest was 992 mb at San Clemente Pier). I'd actually throw out the Baja landfall, have it analyzed as post-tropical over water instead of land (meaning no TC landfalls at all), and then have it with a (remnant low) landfall in California. It's possible the MLC made landfall, but I think the LLC remained offshore and was the new system instead, at least from what I can see.

[ljmac75]

They should have had Idalia as 100 kts at landfall but then 95 kts 15 minutes later for the 1200 best track intensity to emphasize how low end 100 kts it was. Kind of like how Michael was down to 135 kts half an hour after landfall in the best track. I can't believe I just compared those two storms. At least it bucked the trend of intensifying or only weakening very slightly before landfall we've had the past few years.

[Yellow Evan]

123 FL 116 SFMR justifies 115 knots well enough.

How reliable were the SFMR estimates do you think? My KZC relationship calculator is giving me around 110 kts, but of course pressure-wind relationships are finicky.

There have been questions of SFMR in both directions over the years but it's the most surface-based wind observation we have so I'm generally inclined to trust it.

[CrazyC83]

They should have had Idalia as 100 kts at landfall but then 95 kts 15 minutes later for the 1200 best track intensity to emphasize how low end 100 kts it was. Kind of like how Michael was down to 135 kts half an hour after landfall in the best track. I can't believe I just compared those two storms. At least it bucked the trend of intensifying or only weakening very slightly before landfall we've had the past few years.

That's what I had analyzed in real time and I agree, plus they had a higher pressure at that point (953 vs. 950). I also would have had 110 kt at the peak for the reasonings given. I believe Recon last was in Idalia about 1 1/2 hours before landfall and supported 105 kt at that point, but the radar presentation deteriorated so that supports a lower intensity.

[Hurricane2022]

TD 21L is out
https://www.nhc.noaa.gov/data/tcr/AL212 ... ty-One.pdf

And TS Irwin as well
https://www.nhc.noaa.gov/data/tcr/EP102023_Irwin.pdf

[ljmac75]

TD 21L is out
https://www.nhc.noaa.gov/data/tcr/AL212 ... ty-One.pdf

And TS Irwin as well
https://www.nhc.noaa.gov/data/tcr/EP102023_Irwin.pdf

I can't lie, I completely forgot about TD21. When I first saw there was a report for it out I thought it was something they'd uncovered in post-season analysis.

[DioBrando]

TD 21L is out
https://www.nhc.noaa.gov/data/tcr/AL212 ... ty-One.pdf

And TS Irwin as well
https://www.nhc.noaa.gov/data/tcr/EP102023_Irwin.pdf

I can't lie, I completely forgot about TD21. When I first saw there was a report for it out I thought it was something they'd uncovered in post-season analysis.

Spat out my gatorade ngl

[cycloneye]

 https://twitter.com/tbrite89/status/1759320831182749704

[galaxy401]

Sean got published:

https://www.nhc.noaa.gov/data/tcr/AL192023_Sean.pdf

[cycloneye]

I think Otis will be among the last ones or maybe the last to be released because of the Acapulco landfall. They have to go thru all the data from recon and from surface observations on the ground there including looking at data from hurricane chasers.

[cainjamin]

TD 21 is out. Kept at 25kt, no real changes as expected.

[cycloneye]

Ophelia is up.

 https://twitter.com/NHC_Atlantic/status/1761016598758854897




 https://twitter.com/NHC_Atlantic/status/1761017082924224593

[ElectricStorm]

I mean I understand the reasoning I guess but it seems to me like Ophelia has a much better case for 65kts than Idalia does for 115kts. I know it doesn't really matter since it's just 5kts difference but i just find that interesting.