Cat 5 Lee | peak 165 mph 926 mb | post-tropical

[Neoncyclone]

Did anyone see the first pass from recon for pressure? I missed it, the dropsondes should show up soon. 

[1816]

He's pulling a fake out. When it gets clear of the shear and into the bathwater between the Caribbean and the Bahamas its gonna show its ass again. 

[StretchCT]

Some of the trends for the track in spoiler

Spoiler

       

 

Intensities are all over.  SHIPS, HAFS A and B have it going back to Cat 5 briefly

Spoiler

     

 

[StretchCT]

A look at the ECMWF AI tools for the 9-8 runs. Two of three have landfall in New England still. 

Spoiler

0z Fourcast

12z fourcast

0z graphcast

12z graphcast

0z pangu

12z pangu

 

[Burr]

8 minutes ago, StretchCT said:

A look at the ECMWF AI tools for the 9-8 runs. Two of three have landfall in New England still. 

  Hide contents

0z Fourcast

12z fourcast

0z graphcast

12z graphcast

0z pangu

12z pangu

 

We have friends moving to Florida next week.  My wife asked me if there was any danger of problems from the hurricane

I told her they would be at more risk in Maine than Florida.  Can’t say that too often.

[Burr]

looks like a bit of a hot mess, but it’s still flashing some very cold cloud tops.
 

Edited September 9, 2023 by Burr

[StretchCT]

Top HDOBS so far. Must be getting hit pretty hard or something. May not even be a 3 anymore. Levi's video today mentions the unexpected/unmodeled shear. But it really seems to be taking it's toll.  5 and 6 are both in there now. 

Same look with Vort messages.  At least there are Cat 3 flight level winds. 

Lastly the sonde data

That 144mph in mission 5 was at 880mb. There was also a 143 mph at 920mb.

[StretchCT]

Was just looking at Jova and updating that thread.  It looks better than Lee and it's probably barely a hurricane at this point. 

[StretchCT]

A loop of the vortex sounding.  I'm watching the shr/maxshr and the 700-400 mb rh.  It's not until tomorrow afternoon that the average shear will relax.  GFS has the pressure at 970 in that frame. It deepens to 944 by 6z Sept 11 with really no shear.  What's odd is then it has 5 frames, or 30 hours, when it is in a low shear environment but it doesn't develop.  Shear picks up later as it starts north. 

Euro keeps the shear until 12z Sept 10, Sunday morning, and then despite heavier shear after a few frames of light shear, it goes to 914mb. 🤷‍♂️

 

Edited September 9, 2023 by StretchCT

[StretchCT]

The coldest cloudtops are on the south side of the storm

Yet the lightest winds are also on the south side of the storm. This is something I'd love an expert to explain. 

[StretchCT]

The vortex message has 103kt winds which should keep it at Cat 3. 960mb, eye shape not available 🤔, temp in the eye is still 25c, but outside where it was 6c last night is now 18c. Their altitude was not available though they noted the slp guess was made at 8,000 feet. 

Spoiler

Product: NOAA Vortex Message (URNT12 KWBC)
Corrected: This observation corrected a previous observation.
Transmitted: 9th day of the month at 1:19Z
Agency: National Oceanic and Atmospheric Administration (NOAA)
Aircraft: Lockheed WP-3D Orion (Reg. Num. N42RF)
Storm Name: Lee
Storm Number & Year: 13 in 2023 (flight in the North Atlantic basin)
Mission Number: 5
Observation Number: 15

A. Time of Center Fix: 9th day of the month at 0:35:07Z
B. Center Fix Coordinates: 19.04N 56.05W
B. Center Fix Location: 657 statute miles (1,058 km) to the E (86°) from San Juan, Puerto Rico (U.S.).
C. Minimum Height at Standard Level: Not Available
D. Minimum Sea Level Pressure: 960mb (28.35 inHg) - Extrapolated
E. Dropsonde Surface Wind at Center (Undecoded): NA
F. Eye Character: Not Available
G. Eye Shape: Not Available
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 103kts (118.5mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 8 nautical miles to the NNW (340°) of center fix at 0:33:12Z
J. Maximum Flight Level Wind Inbound: From 76° at 104kts (From the ENE at 119.7mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 10 nautical miles (12 statute miles) to the NNW (343°) of center fix at 0:32:31Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 60kts (69.0mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 8 nautical miles to the S (176°) of center fix at 0:37:21Z
N. Maximum Flight Level Wind Outbound: From 258° at 77kts (From the WSW at 88.6mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 6 nautical miles to the S (174°) of center fix at 0:36:37Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 2,435m (7,989ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 25°C (77°F) at a pressure alt. of 2,428m (7,966ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 15°C (59°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Level: Other - Not surface, 1500ft, 925mb, 850mb, 700mb, 500mb, 400mb, 300mb or 200mb
T. Navigational Fix Accuracy: 0.01 nautical miles
T. Meteorological Accuracy: 2 nautical miles

Remarks Section:
 

Sea Level Pressure Extrapolation From: 8000 feet
Maximum Flight Level Wind: 107kts (~ 123.1mph) which was observed 12 nautical miles (14 statute miles) to the ENE (60°) from the flight level center at 23:18:12Z

The latest fix from 6 has the temp difference a little cooler 13 and 20c, but it's at 700mb. It also couldn't describe the eye. And it's pressure was guessed at 966 since the sonde didn't make it to the surface.  Getting into noreaster territory.

Spoiler

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 9th day of the month at 1:30Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5304
Storm Name: Lee
Storm Number & Year: 13 in 2023 (flight in the North Atlantic basin)
Mission Number: 6
Observation Number: 12

A. Time of Center Fix: 9th day of the month at 1:11:20Z
B. Center Fix Coordinates: 19.12N 56.17W
B. Center Fix Location: 650 statute miles (1,046 km) to the E (86°) from San Juan, Puerto Rico (U.S.).
C. Minimum Height at Standard Level: 2,817m (9,242ft) at 700mb
D. Minimum Sea Level Pressure: 966mb (28.53 inHg) - Extrapolated
E. Dropsonde Surface Wind at Center (Undecoded): NA
F. Eye Character: Not Available
G. Eye Shape: Not Available
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 79kts (90.9mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 5 nautical miles to the SW (229°) of center fix at 1:05:30Z
J. Maximum Flight Level Wind Inbound: From 351° at 79kts (From the N at 90.9mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 7 nautical miles to the W (265°) of center fix at 1:04:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 73kts (84.0mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 10 nautical miles (12 statute miles) to the SE (135°) of center fix at 1:14:30Z
N. Maximum Flight Level Wind Outbound: From 235° at 77kts (From the SW at 88.6mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 3 nautical miles to the SE (141°) of center fix at 1:12:30Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 13°C (55°F) at a pressure alt. of 3,055m (10,023ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 20°C (68°F) at a pressure alt. of 3,056m (10,026ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 12°C (54°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Level: 700mb
T. Navigational Fix Accuracy: 0.02 nautical miles
T. Meteorological Accuracy: 1 nautical mile

Remarks Section:
 

Maximum Flight Level Wind: 105kts (~ 120.8mph) which was observed 12 nautical miles (14 statute miles) to the NE (54°) from the flight level center at 23:33:00Z
Sea Level Pressure Extrapolation From: 700mb

 

Edited September 9, 2023 by StretchCT

[StretchCT]

0z intensity. All over the place from just petering out to Cat5

[Burr]

You can see the CDO expand back into the west side in the second half of this IR view.  6 hours between screen grabs.

 

 

 

Edited September 9, 2023 by Burr

[Sentinel]

1 hour ago, StretchCT said:

The coldest cloudtops are on the south side of the storm

Yet the lightest winds are also on the south side of the storm. This is something I'd love an expert to explain. 

I am pretty sure that this is showing you the strength of the wind sheer. Wind sheer is measured in the vertical column and it pushes the storms lopsided. So the cloud tops are exploding, yet the winds translating down are being forced to the east (heavy shear from the SW). So you're seeing the heaviest winds mostly to the East of the center, which is where you would expect it to be with strong SW shear & a rotating hurricane as well. 

Those cloud tops would indicate downdrafts originating from 40-50k feet, so with recon around 8-10k, that would also stand to reason in my mind... Downdrafts start at 45k or so feet and then the shear and rotation interact, so by 8-10k feet, the winds have been forced to the E/NE.

[Neoncyclone]

Looks like Lee has slowed way way down in the last 3 hours, the COC may have even moved SW just a tiny bit, hard to tell. 

Definitely watching this because I don't remember models slowing Lee down as much as it has for the last couple of hours. 

[1816]

2 hours ago, Neoncyclone said:

Looks like Lee has slowed way way down in the last 3 hours, the COC may have even moved SW just a tiny bit, hard to tell. 

Definitely watching this because I don't remember models slowing Lee down as much as it has for the last couple of hours. 

Probably an optical illusion but it looks like it's wobbling south. 

North Caribbean Islands are like:

 

[MaineJay]

4 hours ago, Neoncyclone said:

Looks like Lee has slowed way way down in the last 3 hours, the COC may have even moved SW just a tiny bit, hard to tell. 

Definitely watching this because I don't remember models slowing Lee down as much as it has for the last couple of hours. 

Odds for an East coast LF are still pretty low, I think I saw maybe 2 or 3 in the EPS. The recent 6z GEFS did have a "slow camp" that does threaten the EC.

  I could see how a weaker Lee might drift less to the north and slow compared to guidance.

[MaineJay]

Microwave pass as of 1.5 hours ago suggests the eye is open on the West side. There is 60% of a concentric ring, so we could see that one become dominant, in a bit of ERC, albeit very messy.

[StretchCT]

2 hours ago, MaineJay said:

Odds for an East coast LF are still pretty low, I think I saw maybe 2 or 3 in the EPS.

The trend on the op favors an out to sea solution right now, compared to the 9/7 runs. But it's only to hr 168 and its trended much slower. 

GFS is faster and more definitive on a NS landfall at hr 168

UKIE is the furthest east out of its last runs

[StretchCT]

11:00 AM AST Sat Sep 9
Location: 20.3°N 58.2°W
Moving: WNW at 12 mph
Min pressure: 957 mb
Max sustained: 115 mph

Still looks pinched off to the SW and lopsided on the NE.  Margot doesn't seem healthy either. Disco is a good read and in spoiler. Talks about the recon flight and that it found a 5-10nm wide eye.  There is a SW/NE tilt of the storm. Discrepancies in models as to the relaxation of the shear today, looks like they split the difference between the Euro/Ukie which says it stays strong, and the other models which relax it (see post last night on GFS v Euro and shear).   

Spoiler

Hurricane Lee Discussion Number  17
NWS National Hurricane Center Miami FL       AL132023
1100 AM AST Sat Sep 09 2023

Satellite imagery shows that deep convection continues to pulse
near the center of Lee.  Recent reports from reconnaissance
aircraft and an earlier SSMIS microwave image indicates that Lee 
has a small (5 to 10 n-mi-wide) eye that is obscured by the
higher convective cloud tops.  The NOAA P-3 Hurricane Hunter
aircraft penetrated the eye around 1013 UTC this morning and found
that the pressure was down a few millibars.  The NOAA aircraft
measured peak SFMR surface winds of 100 kt, and 700-mb flight-level
winds of 103 kt.   An Air Force Reserve reconnaissance aircraft
remains in the storm environment, but due to safety concerns was
not able to penetrate the northeastern eyewall on its first pass
through the storm due to very strong convection and mesovortices
orbiting the small eye.  A recent center drop from the Air Force
plane suggest that the minimum pressure is around 957 mb.  Drops
from both aircraft and Doppler radar data from the earlier NOAA
aircraft indicate that there is some southwest to northeast tilt 
to the vortex.  Based on the aircraft data, the initial intensity
remains 100 kt for this advisory.

There is still some question as to how conducive the upper-level
environment will be during the next few days.  The GFS and regional
hurricane models indicate that the shear that has been affecting
Lee will decrease today, and that the upper-level wind pattern will
become much more favorable for restrengthening.  Meanwhile, the
ECMWF and UKMET models depict a less favorable environment, with a
continuation of at least some moderate shear.  The NHC forecast
follows the scenario that there will be at least some relaxation of 
the shear and it calls for gradual restrengthening during the next 
two to three days.  The official wind speed forecast is not as high 
as some of the dynamical model guidance, but is a blend of the HFIP 
corrected consensus model and the IVCN multi-model consensus.

Lee is still moving west-northwestward or 300/10 kt. A mid-level
ridge located over the central Atlantic is forecast to build
west-southwestward during the next few days.  This should keep Lee
on a general west-northwestward heading, but the building ridge is
expected to impede Lee's progress, and a much slower forward speed
is anticipated over the next several days. By Wednesday, Lee should
begin to turn northwestward, and then north-northwestward as a 
mid-latitude trough moves into the Great Lakes region and eastern 
United States.  While the cross track spread in the guidance 
remains fairly low, there is significant long track (forward speed) 
spread in the models.  The GFS and ECMWF depict similar overall 
tracks, but the cross-track spread between those two typically 
reliable models is more than 150 n mi by day 3. The NHC forecast 
splits these speed differences and lies near the various consensus 
aids.


KEY MESSAGES:

1. Lee's core is expected to move well north of the northern
Leeward Islands, the Virgin Islands, and Puerto Rico this weekend
and early next week.

2. Dangerous surf and life-threatening rip currents are affecting
portions of the northern Leeward Islands.  These conditions are
spreading westward and northward and will begin affecting Puerto
Rico, Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda
later today and Sunday.

3. It is way too soon to know what level of impacts, if any, Lee
might have along the U.S. East Coast, Atlantic Canada, or Bermuda
late next week, particularly since the hurricane is expected to
slow down considerably over the southwestern Atlantic.  Regardless,
dangerous surf and rip currents are expected along most of the U.S.
East Coast beginning Sunday and Monday.  Continue to monitor
updates to Lee's forecast during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT  09/1500Z 20.3N  58.2W  100 KT 115 MPH
 12H  10/0000Z 21.0N  59.3W  100 KT 115 MPH
 24H  10/1200Z 21.7N  60.6W  105 KT 120 MPH
 36H  11/0000Z 22.4N  61.9W  110 KT 125 MPH
 48H  11/1200Z 22.9N  63.1W  115 KT 130 MPH
 60H  12/0000Z 23.3N  64.2W  120 KT 140 MPH
 72H  12/1200Z 23.6N  65.3W  120 KT 140 MPH
 96H  13/1200Z 24.4N  67.0W  110 KT 125 MPH
120H  14/1200Z 26.8N  67.8W  105 KT 120 MPH

$$
Forecaster Brown

I thought I'd be camped in front of the computer all day today, but looks like I won't be.  

[StretchCT]

Something caught my eye as I was shutting down

There was some wispy outflow on the WV loop, and then this large bulge.  That's higher up and is beating the shear. 

Vis also shows some signs of a band finally making it to the SW side.

And lastly, if you look really close at the convection popping up over the islands, the cloud tops are now blowing off TO the SW, not indicative of a flow from the SW there.  Now that may be at lower levels still, and there still look like there are some clouds between the islands and Lee that have their tops blowing off NE, but that may be more of a function of the clouds moving so fast to the south. 

This is the 12 utc look at shear, which is neutral, but still 16kts.

Edited September 9, 2023 by StretchCT

[StretchCT]

Latest recon path showing center fixes that Lee is just south of going due west, likely a wobble. The eye was only 12nm wide and open to the east. Inside the eye was 19 and outside was 15c.  Not that great of a difference. 

 

 

[StretchCT]

 

In the early frames you see the lightning in the center.  I think that's the NW eyewall,  an you can see the western half of the storm looks pretty robust and the eastern side looks a bit pinched off.  So wondering if only the eastern side is in the higher shear now.  It also makes sense given the last vort message having the eye open on the east side. 

[Sentinel]

13 minutes ago, StretchCT said:

 

In the early frames you see the lightning in the center.  I think that's the NW eyewall,  an you can see the western half of the storm looks pretty robust and the eastern side looks a bit pinched off.  So wondering if only the eastern side is in the higher shear now.  It also makes sense given the last vort message having the eye open on the east side. 

World class analysis.. As usual

[MaineJay]

D6 ECMWF - GFS Comp.