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Tropical Atlantic
@tropicalatlantic.com
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Hurricane hunter reconnaissance data and models. Website: https://tropicalatlantic.com/ Backup systems hosted at: @hurricanecity.com Our site is not affiliated with any governmental entity.
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The Air Force & NOAA hurricane hunters conducted 33 missions into, and around, #Melissa. Additional information appears in the alternate text for the images.
Thanks. I'll add the disclaimer to all the decoded dropsonde data in my archive when I have a chance. People too often get confused by that and I wanted to make it more clear.
Thanks for checking into it. I'll work on adding a note about that to that sonde in my archive.
Part 3 of 3: "Near the beginning and end of the descent, the effective averaging period shortens as the filter tapers to zero. Earlier dropsondes used a 10-second filter." Thanks.
Part 2 of 3: "Before transmission, the data is processed through a low-pass filter whose half-power amplitude occurs at a 5-second wavelength. This means that wind fluctuations occurring faster than about every five seconds are increasingly damped, reducing short-term noise and turbulence."
But the conversation isn't important. I was wondering what the result sounded like to add. I have to ask scientists when I add something like it:

Part 1 of 3:

"A dropsonde's reported winds represent roughly a five-second smoothed average derived from measurements taken about every 0.25 seconds."
I was trying to put together a disclaimer for my website to add to dropsonde data. I'm not a meteorologist, instead I code things, so I inputted what you had said to ChatGPT to help me understand it some.

That long conversation is here & probably has errors:
tropicalatlantic.com/reconnaissan...
I was able to find raw sonde. Link is commented out on this page:
www.aoml.noaa.gov/hrd/Storm_pa...
So that the link doesn't appear. But file still is:
www.aoml.noaa.gov/ftp/hrd/data...

With launch time of 2005/08/28, 14:21:03.92

I included some screenshots of that section. (truncating part of it)
Reposted by Tropical Atlantic
I deeply respect the work that's been invested into exploring our approaches to tracking high-end tropical cyclones, but I can't in good conscience remain silent regarding the Saffir-Simpson hurricane wind scale (SSHWS) and discussion around a so-called category 6. 🧵 [1/5]
From presentation about Katrina sonde (continued): "If valid, these would be the highest winds recorded to date in the eight years that GPS sondes have been sampling these BL maxima." Thanks.
From presentation about Katrina sonde: "A dropsonde released into the inner edge of that northeast eyewall descended into a mesovortex that contained a boundary layer (BL) wind peak of 120 meters per second (m/s), or 234 knots, at the 866 mb level (approximately 600 meters above the Gulf surface)."
I couldn't really find much about that Katrina sonde. I found one mention of it here from a presentation in 2006:
ams.confex.com/ams/27Hurric...

"The Intensity of Wind Gust Underneath Areas of Deep Eyewall Convection in Hurricanes Katrina and Dennis at Landfall"

PDF:
ams.confex.com/ams/pdfpaper...
Thanks. Does that mean it currently takes 2.5 seconds of data above the pressure altitude and 2.5 seconds below it and averages it all together for the reported pressure altitude? And then for surface wind is it less than 5 seconds or the last five seconds before the sonde terminates?
Also, do you know what the wind reported in the dropsonde message is averaged over? (The ones released in WMO messages) Such as a half second perhaps? Or 0.25, or 1? I would like to put that information on my site. Maybe it has varied over the years and I can put a range if so.
Was 234 knot sonde at the 866mb level in Katrina unreliable?

tropicalatlantic.com/recon/recon....

Nothing really matches close to it for that storm though, expect one with 182 knots on another mission at the 839mb level.

Melissa had another mission with one with 210 knots & other high readings.
Reposted by Tropical Atlantic
WCK is in Jamaica ahead of Category 5 Hurricane Melissa’s landfall. The storm is expected to bring destructive winds, torrential rain & widespread flooding. We’re working with local partners to serve meals as quickly as possible.
Read more: wck.org/news/hurricane-melissa
#ChefsForJamaica
Reposted by Tropical Atlantic
One factor that supported Melissa reaching this record: an Argo float southeast of Jamaica shows a dramatic decrease in upper-level ocean temperature before (18 Oct) and after (28 Oct) the storm.

My heart goes out to the folks in Jamaica facing this powerful hurricane's numerous hazards today. 💔
Reposted by Tropical Atlantic
A climate justice disaster is underway in Jamaica as Hurricane Melissa moves over the island.
Reposted by Tropical Atlantic
Major Hurricane Melissa makes a historic landfall near New Hope, Jamaica.
1:00pm EDT on Oct 28, 2025: #Melissa has made landfall near New Hope, Jamaica with 185mph wind & pressure of 892mb. For wind, ties for strongest landfalling Atlantic hurricane matching Labor Day hurricane in 1935 in Florida Keys & Dorian in 2019 in Bahamas. For pressure, ties for Labor Day hurricane
Katrina had one a bit higher, but I don't if it is valid (234 knots, 269 mph):
tropicalatlantic.com/recon/recon....
At 11:15 am EDT, Air Force hurricane hunters posted about returning to Curacao "after encountering heavy turbulence today while entering the eye of Hurricane Melissa". "During the event, the aircraft briefly experienced forces stronger than normal due to turbulence" www.facebook.com/hurricanehun...
A catastrophic, historical event is about to unfold in Jamaica.

Hurricane warnings are also in effect for parts of eastern Cuba and parts of the Bahamas which will also experience the impact of #Melissa.
If #Melissa makes landfall with a pressure of 892 millibars, it would tie as the lowest pressure on record for a landfalling Atlantic hurricane. The "1935 Labor Day" hurricane in 1935 made landfall in the Florida Keys with a pressure of 892mb.