ATL: LEE - Post-Tropical - Discussion

[PavelGaborik10]

Feels like a make or break burst from Lee here, he's been trying these for days and yet continued to rapidly weaken.

[Airboy]

Movement the last seven hours or so:

00:18:30Z
Coordinates: 20.867N 59.583W
07:13:00Z
Coordinates: 21.267N 60.383W

[Airboy]

roduct: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 10th day of the month at 7:33Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5306
Storm Name: Lee
Storm Number & Year: 13 in 2023 (flight in the North Atlantic basin)
Mission Number: 10
Observation Number: 11

A. Time of Center Fix: 10th day of the month at 7:13:10Z
B. Center Fix Coordinates: 21.26N 60.39W
B. Center Fix Location: 419 statute miles (674 km) to the ENE (62°) from San Juan, Puerto Rico (U.S.).
C. Minimum Height at Standard Level: 2,767m (9,078ft) at 700mb
D. Minimum Sea Level Pressure: 957mb (28.26 inHg)
E. Dropsonde Surface Wind at Center: From 100° at 13kts (From the E at 15mph)
F. Eye Character: Not Available
G. Eye Shape: Not Available
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 86kts (99.0mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 14 nautical miles (16 statute miles) to the NE (50°) of center fix at 7:08:30Z
J. Maximum Flight Level Wind Inbound: From 127° at 93kts (From the SE at 107.0mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 21 nautical miles (24 statute miles) to the NE (49°) of center fix at 7:06:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 84kts (96.7mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 15 nautical miles (17 statute miles) to the SW (225°) of center fix at 7:17:30Z
N. Maximum Flight Level Wind Outbound: From 324° at 85kts (From the NW at 97.8mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 18 nautical miles (21 statute miles) to the SW (226°) of center fix at 7:18:30Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 13°C (55°F) at a pressure alt. of 3,044m (9,987ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 16°C (61°F) at a pressure alt. of 3,043m (9,984ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 13°C (55°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: 1.5 nautical miles

Remarks Section:

Maximum Flight Level Wind: 93kts (~ 107.0mph) which was observed 21 nautical miles (24 statute miles) to the NE (49°) from the flight level center at 7:06:30Z
Maximum Flight Level Temp: 19°C (66°F) which was observed 8 nautical miles to the SW (224°) from the flight level center
General Note About Vortex Messages:
- SFMR and flight level winds are usually averaged over a 10 second period. (The National Hurricane Center's advisory wind speeds are the highest expected winds averaged over a 1 minute period.)

[Teban54]

Is the lack of an eye report due to the EWRC, or has the eye disappeared again?

[Airboy]

Is the lack of an eye report due to the EWRC, or has the eye disappeared again?

I saw this earlier from Kermit:
"G. Eye Shape: Concentric (has an inner and outer eye)"

And with a pressue drope from 960 to 957, maybe an EWRC that has just ended?

[GCANE]

Finally got a good set of microwave soundings

https://tropic.ssec.wisc.edu/real-time/ ... _xsect.gif

Can see the center of the warm core at 200mb
Directly below it is a cold layer above the surface of the ocean, due to rain-induced down drafts.
This allows for efficient transfer of heat from the ocean.
Something that I haven't seen before with Lee.

[GCANE]

Appears the outflow from the core is becoming more symmetrical

https://tropic.ssec.wisc.edu/real-time/ ... plots.html

[GCANE]

960 to 957 mb

[Chris90]

The winds have definitely come down quite a bit since peak, but I do think it should be noted that the rapid weakening ended a day ago, the central pressure has been holding steady between 957-963mbs for the last 24 hours. He's definitely still been struggling with structure and rebuilding, but I do think Lee has a chance to consolidate energy back into a tighter core and intensify again. I would consider his chances a lot less if he was already recurving into the mid-latitudes and much closer to extratropical transition.

Based on microwave, it does look like Lee has nearly built a new eyewall that is getting closer to closing off completely. If he can start to really fully wrap convection without interruption, he should be able to start consolidating energy into a tighter core with some appreciable deepening. He needs a "Do Not Disturb" sign so shear will leave him alone.

[PavelGaborik10]

This thing has been mauled for the last 2 days, I wouldn't get excited about a small 3 MB pressure drop.

Junior has a long way to go before it attempts to make a run at cat 4 again, to say the least.

[Tekken_Guy]

Hurricane Lee is like a football player having an amazing rookie year then suffering a massive injury.

[PavelGaborik10]

One thing of note, Lee has seemingly doubled in size over the last couple of hours.

It appears to be trying to re-organize, but it won't be easy considering the current mess.

[Airboy]

Near the center, from Miss Piggy, so guess that means a pressure around 955-956.
Slow moving.

Time: 09:55:00Z
Coordinates: 21.350N 60.633W
Acft. Static Air Press: 696.3 mb
Acft. Geopotential Hgt: 2,781 m (9,124 ft)
Extrap. Sfc. Press: 951.7 mb (28.11 inHg)








Product: NOAA Vortex Message (URNT12 KWBC)
Transmitted: 10th day of the month at 10:24Z
Agency: National Oceanic and Atmospheric Administration (NOAA)
Aircraft: Lockheed WP-3D Orion (Reg. Num. N43RF)
Storm Name: Lee
Storm Number & Year: 13 in 2023 (flight in the North Atlantic basin)
Mission Number: 11
Observation Number: 04

A. Time of Center Fix: 10th day of the month at 9:54:44Z
B. Center Fix Coordinates: 21.35N 60.66W
B. Center Fix Location: 406 statute miles (654 km) to the ENE (60°) from San Juan, Puerto Rico (U.S.).
C. Minimum Height at Standard Level: 2,731m (8,960ft) at 700mb
D. Minimum Sea Level Pressure: 951mb (28.09 inHg) - Extrapolated
E. Dropsonde Surface Wind at Center (Undecoded): NA
F. Eye Character: Open in the northeast
G. Eye Shape: Elliptical (oval shaped)
G. Orientation of Major Axis in Elliptical Eye: 150° to 330° (SSE to NNW)
G. Length of Major Axis in Elliptical Eye: 30 nautical miles (35 statute miles)
G. Length of Minor Axis in Elliptical Eye: 20 nautical miles (23 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 89kts (102.4mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 13 nautical miles (15 statute miles) to the WSW (253°) of center fix at 9:51:22Z
J. Maximum Flight Level Wind Inbound: From 337° at 88kts (From the NNW at 101.3mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 17 nautical miles (20 statute miles) to the WSW (250°) of center fix at 9:50:26Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 75kts (86.3mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 17 nautical miles (20 statute miles) to the ENE (61°) of center fix at 9:58:38Z
N. Maximum Flight Level Wind Outbound: From 155° at 102kts (From the SSE at 117.4mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 18 nautical miles (21 statute miles) to the ENE (61°) of center fix at 9:58:52Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 12°C (54°F) at a pressure alt. of 3,062m (10,046ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 3,065m (10,056ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 18°C (64°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: 0.01 nautical miles
T. Meteorological Accuracy: 1 nautical mile

Remarks Section:

Sea Level Pressure Extrapolation From: 700mb
Maximum Flight Level Wind: 102kts (~ 117.4mph) which was observed 18 nautical miles (21 statute miles) to the ENE (61°) from the flight level center at 9:58:52Z

[cycloneye]

Pressure down to 951 mbs.

URNT12 KWBC 101024
VORTEX DATA MESSAGE AL132023
A. 10/09:54:44Z
B. 21.35 deg N 060.66 deg W
C. 700 MB 2731 m
D. EXTRAP 951 mb
E. NA
F. OPEN NE
G. E15/30/20
H. 89 kt
I. 253 deg 13 nm 09:51:22Z
J. 337 deg 88 kt
K. 250 deg 17 nm 09:50:26Z
L. 75 kt
M. 061 deg 17 nm 09:58:38Z
N. 155 deg 102 kt
O. 061 deg 18 nm 09:58:52Z
P. 12 C / 3062 m
Q. 19 C / 3065 m
R. 18 C / NA
S. 12345 / 7
T. 0.01 / 1 nm
U. NOAA3 1113A LEE OB 04
SLP EXTRAP FROM 700 MB
MAX FL WIND 102 KT 061 / 18 NM 09:58:52Z

[Airboy]

Pressure down to 951 mbs.

From Miss Piggy so probably it's 954-955 mb in reallity

[IsabelaWeather]

Pressure down to 951 mbs.

From Miss Piggy so probably it's 954-955 mb in reallity

Are they going to fix it?

[cycloneye]

Pressure down to 951 mbs.

From Miss Piggy so probably it's 954-955 mb in reallity

Are they going to fix it?

This is a survellance radar mission. The Air Force plane that will do the fixes departs at 12:30 PM EDT.

FLIGHT THREE - NOAA 43
A. 10/1200Z
B. NOAA3 1113A LEE
C. 10/0830Z
D. 21.5N 60.8W
E. 10/0930Z TO 10/1530Z
F. SFC TO 10,000 FT
G. TAIL DOPPLER RADAR


FLIGHT ONE - TEAL 74
A. 10/1800Z
B. AFXXX 1213A LEE
C. 10/1630Z
D. 22.0N 61.3W
E. 10/1730Z TO 10/2100Z
F. SFC TO 10,000 FT
G. FIX

[Airboy]

Product: NOAA Vortex Message (URNT12 KWBC)
Transmitted: 10th day of the month at 11:44Z
Agency: National Oceanic and Atmospheric Administration (NOAA)
Aircraft: Lockheed WP-3D Orion (Reg. Num. N43RF)
Storm Name: Lee
Storm Number & Year: 13 in 2023 (flight in the North Atlantic basin)
Mission Number: 11
Observation Number: 22

A. Time of Center Fix: 10th day of the month at 11:06:02Z
B. Center Fix Coordinates: 21.45N 60.74W
B. Center Fix Location: 405 statute miles (652 km) to the ENE (59°) from San Juan, Puerto Rico (U.S.).
C. Minimum Height at Standard Level: 2,739m (8,986ft) at 700mb
D. Minimum Sea Level Pressure: 957mb (28.26 inHg)
E. Dropsonde Surface Wind at Center: From 165° at 12kts (From the SSE at 14mph)
F. Eye Character: Open in the south
G. Eye Shape & Diameter: Circular with a diameter of 28 nautical miles (32 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 95kts (109.3mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 12 nautical miles (14 statute miles) to the N (351°) of center fix at 11:03:10Z
J. Maximum Flight Level Wind Inbound: From 80° at 106kts (From the E at 122.0mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 19 nautical miles (22 statute miles) to the N (353°) of center fix at 11:01:28Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 79kts (90.9mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 15 nautical miles (17 statute miles) to the S (177°) of center fix at 11:09:49Z
N. Maximum Flight Level Wind Outbound: From 258° at 88kts (From the WSW at 101.3mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 18 nautical miles (21 statute miles) to the S (178°) of center fix at 11:10:25Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 13°C (55°F) at a pressure alt. of 3,049m (10,003ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 3,071m (10,075ft)
R. Dewpoint Temp & Sea Surface Temp: Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Level: 700mb
T. Navigational Fix Accuracy: 0.01 nautical miles
T. Meteorological Accuracy: 1 nautical mile

Remarks Section:

Maximum Flight Level Wind: 106kts (~ 122.0mph) which was observed 19 nautical miles (22 statute miles) to the N (353°) from the flight level center at 11:01:28Z

[GCANE]

Rotating Towers - back to eyewall building

[cycloneye]

AL, 13, 2023091012, , BEST, 0, 215N, 608W, 95, 956, HU