Category Five Hurricane Lee

[Kevin Reilly]

54 minutes ago, NorthHillsWx said:

Not sure anyone else caught it but the 18z GFS turns Lee into a blizzard in parts of SE Canada 

Sandy did that to West Virginia in 2012 I believe pretty impressive wild stuff!

[StantonParkHoya]

0 US hits among GEFS members

[MUWX]

It appears recon is now headed in for the second pass. 

[WxWatcher007]

I think it's more instructive to use the super ensemble given the split in the GEFS/EPS, and just the fact that those individual members are pushing so far out in time they're not reliable IMO--whether they show land impacts or OTS. You can see in the plot below how confidence drops off rapidly at the latitude of Bermuda. 

[MANDA]

Early first look at 00Z tropical models.  Still bending more westward near end of run.  The end of the run starts to enter the pivotal time as Lee approaches 70W.  Exactly where it is located at 120 hours and the direction and speed of movement at that time will start to tell the tale of where it is ultimately headed.

[StantonParkHoya]

They all bend before 70W when you go out in time 

[etudiant]

2 minutes ago, StantonParkHoya said:

They all bend before 70W when you go out in time 

Is there a good explanation for this critical course change or is it projected based on historical precedent?

[JasonOH]

Just now, etudiant said:

Is there a good explanation for this critical course change or is it projected based on historical precedent?

It’s all modeled based on physics. Big picture there’s high pressure west and NE so it will head north between them

[Random Chaos]

Interesting to note per bending before 70W is that the stronger the storm on the model (specifically hurricane models) the further south the storm stays through the 120hr period. I think it is too soon to say where the recurve happens. Both HAFS-A and HAFS-B are taking the storm due west at 120hr between 23N and 23.5N, while global models such as GFS have already started recurve and are up at 24N heading NW rather than due west. HMON and HREF that don’t strengthen the storm as much are closer to GFS. Also note none of these models predicted current strength at this point - we are 12hrs early on HAFS and HMON never even got this strong.

Also want to ask: what winter storm is predicted on the GFS at day 5 accurately? That’s essentially what we are trying to do with that ridge weakness to turn the storm north. It’s far, far too early to have any faith in a solution. 3 days for tropical systems is about the max you can reliably forecast under best case scenarios.

[GaWx]

As earlier posted regarding the 12Z EPS through 240 excluding the operational, I counted 9 hitting the US: 5 ME, 3 MA, and 1 NY. After 240, I count 2 ME and 1 NJ. So, grand total for 12Z EPS is 12 (24%) meaning the most of any run yet with 7 ME, 3 MA, 1 NY, and 1 NJ with hit dates 9/15-19.

Summary of recent EPS runs' US hits:

9/7 12Z: 12 (24%) 9/15-19 (7 ME, 3 MA, 1 NY, 1 NJ)
9/7 0Z: 10 (20%) 9/15-18 (5 ME, 5 MA)
12Z 9/6: 3 (6%) 9/15-18 (2 ME, 1 MA)
0Z 9/6: 5 (10%)
12Z 9/5: 2 (4%)
0Z 9/5: 4 (8%)  
12Z 9/4: 1 (2%)  
0Z 9/4: 2 (4%)

[WxWatcher007]

Recon moving toward a NW to SE pass

[olafminesaw]

Missing pressure data at the moment. Hopefully temporary 

[WxWatcher007]

Another big time pass. Peak FL winds of 144 & 145kts, with a peak SFMR of 143, 152, and 157kts. Extremely tight core. 

[hawkeye_wx]

2 minutes ago, WxWatcher007 said:

Another big time pass. Peak FL winds of 144 & 145kts, with a peak SFMR of 143, 152, and 157kts. Extremely tight core. 

With a flight wind at 145 kts, it doesn't make sense the SFMR is 157 kts.

[WxWatcher007]

Just now, hawkeye_wx said:

With a flight wind at 145 kts, it doesn't make sense the SFMR is 157 kts.

Agree. I think this one is right around 140kts based on other obs so far. 

[Amped]

Sfmr probably overdone, but still safely a cat 5 now.

[JasonOH]

1 minute ago, Amped said:

Sfmr probably overdone, but still safely a cat 5 now.

Not with SFMR of 145. Tend to need around 150 to get cat 5 with the standard 10% reduction.

[WxWatcher007]

SE eyewall with more standard FL and SFMR around 124 & 123kts respectively. 

[JasonOH]

The last pass looks to have actually had a downdraft. Pressure spiked and altitude dropped

[csnavywx]

We'll have to see the dropsonde, but in especially intense TCs with very strong warm cores, the max wind can be under 10kft and have a smaller-than-normal reduction to the surface. (see: Mitch)

[Floydbuster]

4 minutes ago, JasonOH said:

Not with SFMR of 145. Tend to need around 150 to get cat 5 with the standard 10% reduction.

Wasn't there discussion after Irma that people put way too much stock into the SFMR?

[WxWatcher007]

A worthwhile thread

 

[friedmators]

No ERC imminent per flight level winds.


.

[hawkeye_wx]

928 mb per dropsonde....  darn low, but borderline cat 5 pressure.  Typically, 920 mb is where you get into cat 5 territory.

[WxWatcher007]

[MUWX]

5-6 MB drop in the last night. Still well ahead of the HAFS-A, assuming that continues for the next hour. 

[csnavywx]

4 minutes ago, WxWatcher007 said:

Inversion down below 850mb now. Warm core getting very intense.

[Amped]

2 minutes ago, MUWX said:

5-6 MB drop in the last night. Still well ahead of the HAFS-A, assuming that continues for the next hour. 

Last hour you mean. It's been keeping the steady 5-6mb /hrs pace since 11am

[JasonOH]

10 minutes ago, WxWatcher007 said:

A worthwhile thread

 

That’s super interesting. Thanks for posting that.

[WxWatcher007]

Latest VDM

 

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 8th day of the month at 1:56Z
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: 2
Observation Number: 12 ( See all messages of this type for this mission. )

A. Time of Center Fix: 8th day of the month at 1:28:50Z
B. Center Fix Coordinates: 17.12N 52.18W
B. Center Fix Location: 568 statute miles (913 km) to the ENE (61°) from Bridgetown, Barbados.
C. Minimum Height at Standard Level: 2,538m (8,327ft) at 700mb
D. Minimum Sea Level Pressure: 930mb (27.47 inHg)
E. Dropsonde Surface Wind at Center: From 355° at 20kts (From the N at 23mph)
F. Eye Character: Closed
G. Eye Shape & Diameter: Circular with a diameter of 15 nautical miles (17 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 143kts (164.6mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 6 nautical miles to the N (5°) of center fix at 1:27:00Z
J. Maximum Flight Level Wind Inbound: From 48° at 145kts (From the NE at 166.9mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 9 nautical miles to the NNW (343°) of center fix at 1:25:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 123kts (141.5mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 8 nautical miles to the SE (139°) of center fix at 1:31:00Z
N. Maximum Flight Level Wind Outbound: From 252° at 124kts (From the WSW at 142.7mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 8 nautical miles to the SE (139°) of center fix at 1:31:00Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 7°C (45°F) at a pressure alt. of 3,056m (10,026ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 27°C (81°F) at a pressure alt. of 3,024m (9,921ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 4°C (39°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: 148kts (~ 170.3mph) which was observed 9 nautical miles to the ENE (64°) from the flight level center at 23:38:00Z