NATL: MELISSA - Hurricane - Discussion

[Hurricane2022]

 https://x.com/WeathermanAAA_/status/1982859348184567829

[GCANE]

 https://x.com/AndyHazelton/status/1982837687045247295

[ScottNAtlanta]

 https://x.com/BryceShelton01/status/1982839457628950982

He was live streaming yesterday too

[USTropics]

About the NOAA plane that had to turn back this morning due to turbulence

“NOAA aircraft left the storm early after experiencing severe turbulence in the southwestern eyewall,” the National Hurricane Center wrote in Melissa’s latest forecast discussion.

Hurricane hunters are no stranger to powerful winds and intense turbulence, so what happened Monday morning is remarkable. These teams routinely fly specialized aircraft into the most powerful storms on the planet to collect weather data, which is used to improve track and intensity forecasts.

But this flight was “definitely the most turbulent I’ve ever experienced,” Andy Hazelton, a hurricane expert who confirmed he was on the plane, said on X.

Aircraft positioning data shows that the plane — a WP-3D Orion — was able to take at least two passes through Melissa’s center, collecting critical weather data before experiencing the dangerous turbulence that sent researchers heading for safety.

Was something damaged or can the WC-130 that's in there now handle more turbulence than the Orion?

I have some more information on this from my advisor here (Dr. Bourassa) who assists with recon flights from NOAA. The plane is fine to our knowledge, but on the second eye punch, it went through extreme turbulence (only the 2nd time ever in the past 10 years this has happened) and there was concern there was damage to the plane/instruments. The mission was canceled afterwards and sent back to Lakeland for inspection.

And to add to this, to give you an idea of how violent the mission into Melissa was this morning, that dropsonde in the NE eyewall that recorded 210 kt at 907mb was the highest ever recorded wind measurement from a dropsonde instrument.

[Hurricane2022]

 https://x.com/AndyHazelton/status/1982837687045247295

I found it interesting and funny that Andy’s eyes are somewhat similar to Melissa’s signature on the radar
I wish good luck to him!!!

[galaxy401]

Needs to pass 905 mb to reach the top 10 most intense Atlantic hurricanes. Hugging the threshold now.

[Teban54]

[GCANE]

Slight drying of the core.
Hopefully this is a trend but may be too late for Jamaica.

https://www.tropicaltidbits.com/recon/r ... 7-1647.png

[chaser1]

Whew, that was an interesting several hours.
This concludes our morning episode of Melissa - Rise to Cat 5!
Brought to you by Depends.... where even at 5,000', we've got your back for those special times when you just cant simply choose where you're sitting

Join us this afternoon for some eye-popping updates and a gusto of data!

[TeamPlayersBlue]

Unfortunate that this storm has crawled at the perfect amount of pace to keep it from upwelling enough water to weaken itself. Def seeing a slight jog to the north, but still could be in wobble territory.

[aaaaaa]

Poor birds
 https://x.com/Sausius_wx/status/1982860167860629782

Some birds like Desertas petrel go to hurricane eye to feed themselves when hurricane eye upwelling deep water to surface, so fishs in deep water can be dragged to surface by hurricane eye and bird like Desertas petrel see that like a opportunity to feed themselves by the hurricane

[hipshot]

About the NOAA plane that had to turn back this morning due to turbulence

“NOAA aircraft left the storm early after experiencing severe turbulence in the southwestern eyewall,” the National Hurricane Center wrote in Melissa’s latest forecast discussion.

Hurricane hunters are no stranger to powerful winds and intense turbulence, so what happened Monday morning is remarkable. These teams routinely fly specialized aircraft into the most powerful storms on the planet to collect weather data, which is used to improve track and intensity forecasts.

But this flight was “definitely the most turbulent I’ve ever experienced,” Andy Hazelton, a hurricane expert who confirmed he was on the plane, said on X.

Aircraft positioning data shows that the plane — a WP-3D Orion — was able to take at least two passes through Melissa’s center, collecting critical weather data before experiencing the dangerous turbulence that sent researchers heading for safety.

Was something damaged or can the WC-130 that's in there now handle more turbulence than the Orion?

I don't know about the P-3D but I flew as part of a crew in a P-3B during the late 60's and they ride rough. They have a pretty short
wingspan and they don't bend much as a large wingspan aircraft would. We did a lot of flying about 300 ft. off the ocean and you
can get some wild turbulence in that scenario. There's not much room for error at that altitude.

[edu2703]

 https://x.com/WxAtom/status/1982863271901409615

[Hurricane2022]

No comment
 https://x.com/WeathermanAAA_/status/1982863221125206207

[Hurricane2022]

NHC upgrades it to 150/906

[Iceresistance]

SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...16.5N 78.3W
ABOUT 145 MI...230 KM SW OF KINGSTON JAMAICA
ABOUT 325 MI...525 KM SW OF GUANTANAMO CUBA
MAXIMUM SUSTAINED WINDS...175 MPH...280 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...906 MB...26.76 INCHES

[zzzh]

Melissa's eye is one of the driest eye ever recorded.

[GCANE]

 https://x.com/AndyHazelton/status/1982860690860704089

[USTropics]

There are a lot of questions on how deep can Melissa get, or in other words what is the theoretical minimum pressure that this system can achieve. The answer is called maximum potential intensity (MPI). This is quite literally the most dangerous part of the Atlantic ocean in terms of MPI due to the sea surface temperatures (and the depth it goes to). Melissa could park over this region for days, and it would not upwell cooler waters:



If you want to know the exact details (it's a bit of a read), but here is a post I made a while ago that outlines the mechanics of a hurricane and how to calculate MPI.

Determining the maximum wind speed a tropical cyclone can reach involves applying some thermodynamics, namely we model the mechanisms of a tropical cyclone as a Carnot heat engine (not too dissimilar from a motor/car engine). This allows us to determine the MPI (maximum potential intensity) as others have mentioned by using the Carnot cycle. But what exactly is a Carnot cycle and how does this physically look?

The Carnot cycle is characterized by four stages of expansion and compression. I created a crude diagram below to better show these stages in a cross-section of a mature hurricane:
The first stage (A→B) is isothermal expansion. In this stage, air flows inward towards the low pressure center for the storm.
The second stage (B→C) is adiabatic expansion. Air begins to rise adiabatically up the eyewall to the top of the atmosphere (TOA).
The third stage (C→D) is isothermal compression. Air now flows outward at this point and radiative cooling begins.
The fourth stage (D→A) is adiabatic compression, as air now sinks and begins to warm. Pressure increases, and the cycle begins again.



Now that we can identify the inner mechanisms of a hurricane, what are we really trying to show here? First, we now know the ocean-hurricane interaction provides the fuel pump, and as a hurricane intensifies, a feedback loop begins. As wind speeds begin to increase, this also increases the evaporation rate, which in turn increases the latent heat supply that drives our Carnot engine.

Secondly, we can now apply some math equations to quantify what this value is. From our previous statement, we know our main source of latent heat/warm reservoir is our sea surface temperatures (i.e., through the evaporation process, latent heat is released). If we also treat our TOA as the outflow (think cool reservoir), we can now mathematically model a hurricane using the Carnot efficiency ratio. Skipping some of the setup using the First Law of Thermodynamics and determining work done for each leg of the cycle, we arrive at our most simplified equation:



Where Ts is our inflow surface temperature of the ocean (hot reservoir), To is our TOA outflow temperature (cold reservoir), and E is a ratio of enthalpy and surface drag (i.e., heat exchange coefficients). In this sense, we can state the mechanical energy produced by our heat engine (V, or work done) is the energy of the winds (hurricane intensity)!

If we consider E to be constant (not the safest assumption, but will do for now), our maximum potential intensity, as stated by thermodynamics, is simply governed by the outflow temperature and the inflow temperature. In other words, this means changes in our cloud top convection or sea surface temperature strictly dictates the maximum wind speeds a tropical cyclone can reach.

With all that said, it’s important to note that we’re discussing the theoretical maximum potential intensity. Cyclones rarely reach this intensity because this requires ideal atmosphere and oceanic conditions—in other words, environmental factors rarely allow a system to reach MPI. This includes
Land interaction: this obviously removes our fuel source (latent heat release from the ocean surface)
Vertical wind shear: This causes the cyclones core to become asymmetrical, weakening the convective pattern or even creating an absence of convection on the upshear side of the cyclone (this raises our To)
Ocean interaction: As stated previously, increased wind speed can increase evaporation, but too much wind speed over a very specific area of the ocean can also cause upwelling. This localized cooling of the ocean layer decreases our Ts variable.
Dry air entrainment: If our adiabatic cooling/expansion leg of the cycle becomes disrupted by dry air, this decreases the convective potential of our cyclone and To.

[Hurricane2022]

 https://x.com/NickKrasz_Wx/status/1982864599872684163