ATL: LEE - Post-Tropical - Discussion

[ScottNAtlanta]

Unrelated to feline villains of yore...
I included all our Caribbean friends in my prayers today that they avoid any impacts from Lee.

[Sciencerocks]

[REDHurricane]

Up to 60kt.

AL, 13, 2023090612, , BEST, 0, 139N, 451W, 60, 994, TS

Yesterday it was 30 kt at 15z so that's a 30 kt increase in 21 hours. Does that still count as RI since the 30 kt value was when it was still a TD instead of a TS? If so than Lee already meets the RI criteria.

Yes, I believe so. The NHC definition of RI is "an increase in the maximum sustained winds of a tropical cyclone of at least 30 kt in a 24-h period," and since a tropical depression is categorized as a tropical cyclone, I think that this would have to qualify. Pretty impressive for a storm that hasn't really even gotten going yet

[kevin]

A big burst of convection now directly over the COC. Might be enough to take Lee to the next stage of its RI process.

[ElectricStorm]

BULLETIN
Tropical Storm Lee Advisory Number 5
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Wed Sep 06 2023

...LEE CLOSE TO HURRICANE STRENGTH...
...LIKELY TO RAPIDLY INTENSIFY INTO AN EXTREMELY DANGEROUS MAJOR
HURRICANE BY SATURDAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.1N 45.5W
ABOUT 1200 MI...1930 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...994 MB...29.36 INCHES

[Buck]

...LEE CLOSE TO HURRICANE STRENGTH... ...LIKELY TO RAPIDLY INTENSIFY INTO AN EXTREMELY DANGEROUS MAJOR HURRICANE BY SATURDAY...
11:00 AM AST Wed Sep 6
Location: 14.1°N 45.5°W
Moving: WNW at 14 mph
Min pressure: 994 mb
Max sustained: 70 mph

[Iceresistance]

ASCAT's luck finally runs out, it missed Lee.

[Sciencerocks]

 https://twitter.com/philklotzbach/status/1699438885452026231

[hipshot]

BULLETIN
Tropical Storm Lee Advisory Number 5
NWS National Hurricane Center Miami FL AL132023
1100 AM AST Wed Sep 06 2023

...LEE CLOSE TO HURRICANE STRENGTH...
...LIKELY TO RAPIDLY INTENSIFY INTO AN EXTREMELY DANGEROUS MAJOR
HURRICANE BY SATURDAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.1N 45.5W
ABOUT 1200 MI...1930 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...994 MB...29.36 INCHES

This may be nothing, but I recall the last heading as 290 and this one is 285, just a little more southern droop. I may be wobble watching
already though.

[cycloneye]

For our friends in the Leeward Islands, here is an important message from NHC.

1. Lee is forecast to become a major hurricane by early Saturday and
could bring impacts to the northern Leeward Islands this weekend.
While it is too soon to determine the location and magnitude of
these possible impacts, interests in this area should monitor the
progress of Lee and further updates to the forecast.

2. Swells generated by Lee are expected to reach portions of the
Lesser Antilles on Friday. These swells are likely to cause
life-threatening surf and rip current conditions.

[SconnieCane]

https://twitter.com/philklotzbach/status/1699438885452026231

Impressive company there, even beating out the prolific 2020 which was one of the most bizarre years I (and I'd wager most of us) have ever tracked. Sky-high expectations going in, spamming tropical cyclogenesis from late spring onward, but being extremely lean on quality (apart from Laura's last 12 hours before landfall)/ACE-generators until quite late in the season; add to that COVID making that year and all since kind of blur together.

[Ken711]

 https://twitter.com/RyanMaue/status/1699440008912937443

[cycloneye]

Video shortly.

 https://twitter.com/TropicalTidbits/status/1699443142179860737

[Iceresistance]

That convective burst at the southern side of the CoC might be the beginning of Lee's forecasted RI


https://s11.gifyu.com/images/Sgyox.gif

[Woofde]

https://twitter.com/philklotzbach/status/1699438885452026231

Impressive company there, even beating out the prolific 2020 which was one of the most bizarre years I (and I'd wager most of us) have ever tracked. Sky-high expectations going in, spamming tropical cyclogenesis from late spring onward, but being extremely lean on quality (apart from Laura's last 12 hours before landfall)/ACE-generators until quite late in the season; add to that COVID making that year and all since kind of blur together.

What was so impressive about 2020 was how it kept pace the entire season. Constant named storms and even strong majors into November. If 2023 does that with an El nino I'd be concerned.

[Iceresistance]

ADT is increasing again

Final T# Adj T# Raw T#
2.6 2.9 3.3

[Teban54]

https://twitter.com/philklotzbach/status/1699438885452026231

Impressive company there, even beating out the prolific 2020 which was one of the most bizarre years I (and I'd wager most of us) have ever tracked. Sky-high expectations going in, spamming tropical cyclogenesis from late spring onward, but being extremely lean on quality (apart from Laura's last 12 hours before landfall)/ACE-generators until quite late in the season; add to that COVID making that year and all since kind of blur together.

I love how everyone collectively forgets the existence of Teddy in 2020.

[TheBigO]

Kind of. The more intense the storm, the lower the height the mb is. For example, typhoon tips 850mb was only a few hundred feet above the surface.

Well, this is different, this is the atmospheric height level.

Yes, these maps are standard atmospheric heights from MSLP. Keep in mind, when referring to cyclones, a cyclone typically peaks at 500mb in height (i.e., it does not extend beyond this point in the atmosphere), so we consider this the upper levels. Truly, 200mb is a more accurate description of the upper levels of the atmosphere, but the features at 200mb are completely different (jet streams, Rossby waves, upper/lower-level highs/lows, atmospheric fronts, etc.) . While the levels of the atmosphere are not uniform throughout all location points on earth, a general guideline for tropical systems is:

Surface (950-1000mb) < 5k ft (1.5 km)
Low levels (850mb) < 10k ft (3 km)
Mid levels (700mb) < 18k ft (5.5 km)
Upper levels (500mb) < 30k ft (9.2 km)
Upper troposphere (200mb) > 39k ft (11.8 km)

Thanks! This is great educational/contextual info! Helped me a lot.

[mantis83]

lee still looks a little disjointed on satellite, low and mid level centers aren't aligned quite yet. that will sort itself out soon enough. after that, look out!

[eastcoastFL]

Not much out there to stand in his way