ATL: LEE - Post-Tropical - Discussion

[ElectricStorm]

It appears as if Lee is going to underperform the models significantly. The HAFS models were consistently expecting Lee to break the 170-kt barrier, and even the NHC forecast had this peaking at 155 kt. For now, it appears as if Lee will peak at only 145 kt unless wind shear subsides.

I feel like we've normalized 145kt too much to say "only 145kt". Regardless, Lee still has several days to fluctuate in intensity so I wouldn't be surprised if it has a secondary peak maybe exceeding its first.

145 kt sure seems low in comparison to all the Irma/Dorian redux expectations and those insane HAFS-A/B runs. The odds of this actually breaking 170 kt were pretty low.

I mean it's only 10kts less than Irma. Really not that much lower. And the strongest storm in the basin in terms of windspeed since Dorian. Not to mention it could easily reintensify over the weekend.

No way Lee is an underperformance. At all

[Teban54]

Lee might be a good case study for the NHC to consider 7-day forecasts especially when models are in excellent agreement on some kind of turn north. Every model we have has pretty consistently showing a turn north for days and now it is just beyond the NHC 5-day track. In these situations, with such a powerful hurricane, it would be nice to show that turn with a wider cone of uncertainty after day 5 than a 5-day track with no turn at all to help ease some fears.

On the other hand, imagine if Dorian had 7-day forecasts with multiple advisories showing SE FL landfalls. Or Ian having 7-day forecasts with the windshield wiper forecast track.

[cycloneye]

130kt at Best Track.

AL, 13, 2023090818, , BEST, 0, 186N, 550W, 130, 941, HU

[mitchell]

Lee might be a good case study for the NHC to consider 7-day forecasts especially when models are in excellent agreement on some kind of turn north. Every model we have has pretty consistently showing a turn north for days and now it is just beyond the NHC 5-day track. In these situations, with such a powerful hurricane, it would be nice to show that turn with a wider cone of uncertainty after day 5 than a 5-day track with no turn at all to help ease some fears.

Its an interesting thought, and one that probably makes more sense for a system like this, and less sense with certain other scenarios like a system spinning up in the late fall in the GOM or Caribbean with unpredictable steering currents. The NHC seems to prefer a standard suite of products that are uniformly implemented for every system.

[dukeblue219]

Lee might be a good case study for the NHC to consider 7-day forecasts especially when models are in excellent agreement on some kind of turn north. Every model we have has pretty consistently showing a turn north for days and now it is just beyond the NHC 5-day track. In these situations, with such a powerful hurricane, it would be nice to show that turn with a wider cone of uncertainty after day 5 than a 5-day track with no turn at all to help ease some fears.

Its an interesting thought, and one that probably makes more sense for a system like this, and less sense with certain other scenarios like a system spinning up in the late fall in the GOM or Caribbean with unpredictable steering currents. The NHC seems to prefer a standard suite of products that are uniformly implemented for every system.

If it were me, I'd put it in the Discussion at least, that while the forecast ends at 120 hours and uncertainty exists (etc), long term model runs indicate a high probability of an eventual turn to the north, interests in New England and maritime Canada should be watching closely over the next 3-4 days as the forecast develops.

[Ken711]

 https://twitter.com/RyanMaue/status/1700202695489991040

[Deshaunrob17]

It appears as if Lee is going to underperform the models significantly. The HAFS models were consistently expecting Lee to break the 170-kt barrier, and even the NHC forecast had this peaking at 155 kt. For now, it appears as if Lee will peak at only 145 kt unless wind shear subsides.

The HWRF might be doing good with Lee. I remember asking myself on Wednesday, why is the HWRF model not bullish as the others. It kept having the peak in the 930s on Friday and from there remained steady in the 940s for like 4 days.
While other Hurricane models were going 910s, 900s and sub 900s

[WalterWhite]

130kt at Best Track.

AL, 13, 2023090818, , BEST, 0, 186N, 550W, 130, 941, HU

That shear is doing significant damage to Lee.

[Hurricane2022]

 https://twitter.com/Mike_Clay/status/1699962945449472037

[cycloneye]

Video by Dr Levi Cowan.

 https://twitter.com/TropicalTidbits/status/1700237106126454831

[eastcoastFL]

I’m not sure what to make of Lee right now. A lot of white and pink on IR but the eye is, collapsing?

[Craters]

I am somewhat confused on why Lee is moving NW and the steering patterns favor west motion

700-850 mb
https://s11.gifyu.com/images/S4247.gif
https://s11.gifyu.com/images/S4247.gif

200-700 mb
https://s11.gifyu.com/images/S424I.gif
https://s11.gifyu.com/images/S424I.gif

My completely unprofessional guess would be because of beta drift (Coriolis forces).

[galaxy401]

The moderate shear and dry mid-level air that has affected Lee
today is not expected to abate during the next 12-24 hours. After
that time, the upper-level wind pattern could become a little more
conducive for re-strengthening. However, the timing of eyewall
replacement cycles makes it difficult to predict when Lee might
re-intensify.

Seems like the NHC isn't confident on what the shear will do either. They seem to imply the shear might not go away anytime soon.

[Sciencerocks]

[aspen]

The moderate shear and dry mid-level air that has affected Lee
today is not expected to abate during the next 12-24 hours. After
that time, the upper-level wind pattern could become a little more
conducive for re-strengthening. However, the timing of eyewall
replacement cycles makes it difficult to predict when Lee might
re-intensify.

Seems like the NHC isn't confident on what the shear will do either. They seem to imply the shear might not go away anytime soon.

This shear really came out of nowhere. The hurricane models were forecasting a phenomenal environment until around Tuesday, a little before it starts its turn.

[Tekken_Guy]

The moderate shear and dry mid-level air that has affected Lee
today is not expected to abate during the next 12-24 hours. After
that time, the upper-level wind pattern could become a little more
conducive for re-strengthening. However, the timing of eyewall
replacement cycles makes it difficult to predict when Lee might
re-intensify.

Seems like the NHC isn't confident on what the shear will do either. They seem to imply the shear might not go away anytime soon.

What does that mean regarding Lee’s chance of returning to Category 5.

[galaxy401]

The moderate shear and dry mid-level air that has affected Lee
today is not expected to abate during the next 12-24 hours. After
that time, the upper-level wind pattern could become a little more
conducive for re-strengthening. However, the timing of eyewall
replacement cycles makes it difficult to predict when Lee might
re-intensify.

Seems like the NHC isn't confident on what the shear will do either. They seem to imply the shear might not go away anytime soon.

What does that mean regarding Lee’s chance of returning to Category 5.

Well if the shear goes away then a Cat 5 is likely. If it stays for the next couple days, the odds are quite low.

[TorSkk]

Eye is now completely gone on IR

[RevanTheJedi96]

Crazy how deteriorated Lee looks now

[GeneralChow]

https://tropic.ssec.wisc.edu/real-time/mimtc/2023_13L/web/last24hrs.gif

I’m not sure what to make of Lee right now. A lot of white and pink on IR but the eye is, collapsing?

I'm pretty sure that western eye-wall collapsed. Lee charged into the strongest SSW Shear, and it looks like the whole system is off balance. It actually looks like the vortex is starting to stretch toward the southern Convection on Satellite.