NATL: MELISSA - Hurricane - Discussion

[aspen]

Unbelievable drop in the S eyewall — 172 kt at the surface and increasing to 203 kt (!!!) at 916mb and 219 kt (!!!) at 906mb. Could 170 kt be justifiable with this?

[gib]

Utterly stunned. This is historic and incredible and catastrophic and tragic.

[NotoSans]

Planes are still at operational level at 700mb. Flight path could be different because the storm is now close to land, but there could be another pass.

[GCANE]

Over 700' drop in elevation in a few seconds in recon.
Momentarily weightless and breakfast less.

Heading back to the barn due to exceeding g-limit

[Fancy1002]

Over 700' drop in elevation in a few seconds in recon.
Momentarily weightless and breakfast less.

Heading back to the barn due to exceeding g-limit

What’s g limit?

[Chris_in_Tampa]

About that most recent sonde. (OB06 from NOAA mission 23)

Sondes have momentary winds, not 1 minute sustained.

I was looking up information about interpreting the two things mentioned below yesterday:


From:
https://www.noaa.gov/sites/default/file ... nan-sm.pdf



Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding):
- Wind Direction: 210° (from the SSW)
- Wind Speed: 192 knots (221 mph)

Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding:
- Lowest 150m: 157 gpm - 7 gpm (515 geo. feet - 23 geo. feet)
- Wind Direction: 195° (from the SSW)
- Wind Speed: 188 knots (216 mph)



192 * 0.8 = 153.6 knots = 177 mph based on mean boundary level
188 * 0.83 = 156.04 knots = 179 mph based on lowest 150 meters

So that sonde is in line with the 180mph wind.

[MEANINGLESS_NUMBERS]

Over 700' drop in elevation in a few seconds in recon.
Momentarily weightless and breakfast less.

Heading back to the barn due to exceeding g-limit

What’s g limit?

2.5Gs

[Michele B]

 https://x.com/iCyclone/status/1983174867462537491

Will Josh be streaming live?

I pray for his safety. It doesn't sound like his "safe" place is very safe.

[Teban54]

[sbcc]

Over 700' drop in elevation in a few seconds in recon.
Momentarily weightless and breakfast less.

Heading back to the barn due to exceeding g-limit

What’s g limit?

The amount of g forces an airframe is rated to handle. Exceed it and parts can start coming off.

[CrazyC83]

Based on that dropsonde, I would go with 175 kt for the intensity.

[storm_in_a_teacup]

Holy cow!!! I cannot believe what I'm waking up to, SUB 900 landfall!!? No way, this is the Atlantic's Haiyan - are we seriously tying 1935, or even beating the 892 mb landfall!?

Melissa might just be the mother of all landfalling Atlantic hurricanes, prayers for Jamaica!!

I’m kinda disappointed Melissa got stronger than Labor Day as Labor Day is one of my main hurricane characters.

Especially given it’s kind of in poor taste to have a recent hurricane with survivors in living memory as a protagonist.

(Humor=tragedy+time and all that)

[MEANINGLESS_NUMBERS]

Based on that dropsonde, I would go with 175 kt for the intensity.

Surely that dropsonde captured a gust and doesn't represent 1-minute sustained winds.

[Fancy1002]

Heading back to the barn due to exceeding g-limit

What’s g limit?

2.5Gs

Not what’s the G limit, what is G limit, the term?

[GCANE]

Over 700' drop in elevation in a few seconds in recon.
Momentarily weightless and breakfast less.

Heading back to the barn due to exceeding g-limit

What’s g limit?

g-force.
Apparent force one feels in the plane.
g=1 is normal downward gravity.
g=2 is twice the force of gravity.
g= -1 is standing on your head.
etc

[PavelGaborik10]

Based on that dropsonde, I would go with 175 kt for the intensity.

They won't though.

[Snoopie]

Over 700' drop in elevation in a few seconds in recon.
Momentarily weightless and breakfast less.

Heading back to the barn due to exceeding g-limit

What’s g limit?

When an aircraft has to making abrupt maneuvers they put extra forces on the aircraft measured in Gs. 1 g is just standard earth gravity. So must people are always experiencing 1g. Fighter jets can pull up to 8ish g's but they're specially designed for it. Most passenger aircraft experience maybe 1.2, 1.3 g's.

[MEANINGLESS_NUMBERS]

What’s g limit?

2.5Gs

Not what’s the G limit, what is G limit, the term?

It is a measure of force, relative to earth's gravity. You are currently experiencing 1 g of force due to gravity. If you are accelerating upwards at 9.8 m/s^2 you are experiencing 2 g. The plane's structural components are rated for +3.0 and -2.0 Gs. The squishy humans inside may have lesser tolerances.

[USTropics]

Based on that dropsonde, I would go with 175 kt for the intensity.

Surely that dropsonde captured a gust and doesn't represent 1-minute sustained winds.

That 219kt was instantaneous and aloft. If you consider the entire vertical measurements though (gusts would be smoothed out), what CrazyC83 is stating is justifiable. It was a southern quadrant drop too, which is where the strongest winds have been this morning.

[Beef Stew]

Based on that dropsonde, I would go with 175 kt for the intensity.

I could see 165; what's your line of thought for sustained 175?

(P.S.- I say that not intending to sound critical, but out of curiosity and as someone who really appreciates all your insight!)