Category Five Hurricane Lee

[MJO812]

23 minutes ago, GaWx said:

The 18Z GEFS US landfalls went back down some from the ~13 of the 12Z to 8 (26%): 3 ME, 3 MA, 2 NY

So, last 10 GEFS runs: 26%, 42%, 10%, 13%, 26%, 16%, 16%, 10%, 10%, 10%

There were more hooking left members 

[MJO812]

[GaWx]

46 minutes ago, MJO812 said:

There were more hooking left members 

Indeed, five (16%) hooked left enough to landfall anywhere from near the RI/MA border W to almost NYC while there were fewer ME landfalls. That's quite a change.

[TheDreamTraveler]

00z GFS is looking very similar to 18z. Has Lee taking a left hook into New England

[USCG RS]

No one on the EC should be writing this off right now. 

[GaWx]

1. The 0Z GFS has a move into the Bay of Fundy followed by a landfall on New Brunswick on 9/17.

2. The 0Z ICON and CMC both hit Nova Scotia (9/16 and 9/17, respectively).

3. The 0Z UKMET hits Nova Scotia on 9/17:

HURRICANE LEE        ANALYSED POSITION : 22.3N  61.9W

     ATCF IDENTIFIER : AL132023

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    0000UTC 11.09.2023    0  22.3N  61.9W      952            77
    1200UTC 11.09.2023   12  23.2N  63.0W      954            86
    0000UTC 12.09.2023   24  23.7N  64.4W      949            87
    1200UTC 12.09.2023   36  24.1N  65.6W      949            86
    0000UTC 13.09.2023   48  24.7N  66.4W      948            79
    1200UTC 13.09.2023   60  25.7N  67.2W      948            75
    0000UTC 14.09.2023   72  27.0N  67.3W      945            80
    1200UTC 14.09.2023   84  28.8N  67.9W      948            74
    0000UTC 15.09.2023   96  30.3N  67.9W      947            70
    1200UTC 15.09.2023  108  32.0N  67.5W      951            68
    0000UTC 16.09.2023  120  34.7N  66.5W      954            69
    1200UTC 16.09.2023  132  38.0N  66.1W      961            65
    0000UTC 17.09.2023  144  40.6N  66.7W      964            57
    1200UTC 17.09.2023  156  42.3N  66.5W      974            46
    0000UTC 18.09.2023  168  44.7N  63.9W      989            41

 

[Sportybx]

Lee was moving around 13 mph and all the models were showing a wnw to a nw track . Since it slowed to 8mph it’s now taking that left hook . Is it possible the change of speed is missing the ridge and that’s why we are getting the left hook ? 

[Random Chaos]

0Z GEFS has 100% of the members showing a landfall in either New England or adjacent Canada, with a fairly even distribution between Long Island through Newfoundland & PEI.

 

[GaWx]

1 hour ago, Random Chaos said:

0Z GEFS has 100% of the members showing a landfall in either New England or adjacent Canada, with a fairly even distribution between Long Island through Newfoundland & PEI.

 

 This GEFS (0Z) doesn't have 5 sharp left turning members going into RI/LI like the 18Z, but it still has one going into E LI. There's ~3 into MA and ~5 into ME. So, a total of 9 (29%). So, this is the 3rd active run in a row for the NE.
 

Last 11 GEFS runs: 29%, 26%, 42%, 10%, 13%, 26%, 16%, 16%, 10%, 10%, 10%

[GaWx]

0Z Euro: Very similar to the 0Z GFS, this has a NB landfall 9/17 near 977 mb.

[jconsor]

Need to look at more than just 500 mb heights/winds to get a better idea of Lee's future track.  Very important to consider the 250 mb level IMHO.  There have been a number of cases in which hurricanes were lured NW toward the SE US/Mid-Atlantic coast by a negative tilt trough or cutoff low at 250 mb, even when the 500 mb trough was relatively weak.  

It *usually* takes a deep 500 mb trough from near the Great Lakes to the TN Valley or southern Appalachians (570 dm contour down to at least 40N) to pull a hurricane northward from near/east of the Bahamas toward a New England landfall, and also accelerate it enough (forward speed >25 kt) so it maintains hurricane strength despite the cooler waters N of the Gulf Stream.  Look at the upper air patterns for 1938, Carol, Edna, Gloria and Bob and you will see such a deep trough. 

On the other hand, the 1893 NYC hurricane and Irene both had much weaker/further north troughs at 500 mb than the hurricanes mentioned above.  The 1944 Great Atlantic hurricane had an initially deep trough over the W. Great Lakes/OH Valley two days before landfall, but it was weakening/lifting out as the hurricane turned N up the East Coast.  In both the 1893 and 1944 hurricanes, a sharp trough at 250 mb along with a strong jet streak from the NE US to SE Canada helped to compensate for the lack of a deep trough at 500 mb.

Also in Lee's case, a relatively deep/neg tilt 250 mb eastern US trough  and 100+ kt jet streak as shown by the GEFS would likely help to compensate.  Also important to note - since the frequency of blocking patterns appears to have increased in the past 30 years since the last New England landfall, and there has been substantial warming of SSTs in those 30 years, history may not be as much of a guide as we would hope.  In other words, perhaps in the next few decades we will see increasing frequency of slower-moving strong TSs or lower-end hurricanes (i.e similar to Irene, Sandy and Henri) landfalling in the northern mid-Atlantic and New England vs. what was seen up until ~1990.
 

[jconsor]

4 minutes ago, jconsor said:

Need to look at more than just 500 mb heights/winds to get a better idea of Lee's future track.  Very important to consider the 250 mb level IMHO.  There have been a number of cases in which hurricanes were lured NW toward the SE US/Mid-Atlantic coast by a negative tilt trough or cutoff low at 250 mb, even when the 500 mb trough was relatively weak.  

It *usually* takes a deep 500 mb trough from near the Great Lakes to the TN Valley or southern Appalachians (570 dm contour down to at least 40N) to pull a hurricane northward from near/east of the Bahamas toward a New England landfall, and also accelerate it enough (forward speed >25 kt) so it maintains hurricane strength despite the cooler waters N of the Gulf Stream.  Look at the upper air patterns for 1938, Carol, Edna, Gloria and Bob and you will see such a deep trough. 

On the other hand, the 1893 NYC hurricane and Irene both had much weaker/further north troughs at 500 mb than the hurricanes mentioned above.  The 1944 Great Atlantic hurricane had an initially deep trough over the W. Great Lakes/OH Valley two days before landfall, but it was weakening/lifting out as the hurricane turned N up the East Coast.  In both the 1893 and 1944 hurricanes, a sharp trough at 250 mb along with a strong jet streak from the NE US to SE Canada helped to compensate for the lack of a deep trough at 500 mb.

Also in Lee's case, a relatively deep/neg tilt 250 mb eastern US trough  and 100+ kt jet streak as shown by the GEFS would likely help to compensate.  Also important to note - since the frequency of blocking patterns appears to have increased in the past 30 years since the last New England landfall, and there has been substantial warming of SSTs in those 30 years, history may not be as much of a guide as we would hope.  In other words, perhaps in the next few decades we will see increasing frequency of slower-moving strong TSs or lower-end hurricanes (i.e similar to Irene, Sandy and Henri) landfalling in the northern mid-Atlantic and New England vs. what was seen up until ~1990.
 

I wrote a detailed thread about the trend toward a sharper trough at 250 mb from the eastern Great Lakes to the Carolinas, and how this could increase the risk of Lee continuing N or NNW toward New England instead of turning NNE into Atlantic Canada.
 

 

[NorthHillsWx]

Lee keeps trying, but I think a combination of done pesky dry air and possibly some remnant shear keep plaguing the system keeping it in check 

[NorthHillsWx]

Recon is showing signs of a double wind maximum 

[olafminesaw]

4 minutes ago, NorthHillsWx said:

Recon is showing signs of a double wind maximum 

The HAFS A and B both have it in the middle of a ERC and don't complete it for about 48 hours. The Navy.mil site seems to be down, so hard to say how far along the process is, but after the last ERC we were left with quite a bit of competing bands that held strength in check initially and ultimately led to our current ERC

[WxWatcher007]

1 hour ago, NorthHillsWx said:

Recon is showing signs of a double wind maximum 

That may just keep this from a second cat 4 peak and allow for the wind field to expand even more than it already has. Going to be a very large storm as it moves northward. 

[HKY_WX]

On 9/9/2023 at 6:12 AM, Torch Tiger said:

we've all let it go days ago, besides the diehard weenies.

And this is why you guys are weenies.

[Eskimo Joe]

 

[yoda]

BULLETIN
Hurricane Lee Advisory Number  25
NWS National Hurricane Center Miami FL       AL132023
1100 AM AST Mon Sep 11 2023

...NOAA HURRICANE HUNTERS INDICATE THAT LEE REMAINS A MAJOR
HURRICANE...
...HAZARDOUS SURF AND RIP CURRENT CONDITIONS EXPECTED AT BEACHES
ACROSS THE WESTERN ATLANTIC ALL WEEK...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...23.5N 63.5W
ABOUT 365 MI...590 KM N OF THE NORTHERN LEEWARD ISLANDS
ABOUT 615 MI...985 KM S OF BERMUDA
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...948 MB...28.00 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

Interests in Bermuda should monitor the progress of Lee.

[yoda]

Hurricane Lee Discussion Number  25
NWS National Hurricane Center Miami FL       AL132023
1100 AM AST Mon Sep 11 2023

Lee has been holding steady in strength this morning.  The NOAA 
Hurricane Hunters have been investigating Lee and found that the 
minimum pressure was around 948 mb while a combination of the 
measured flight-level and SFMR winds support holding the initial 
intensity at 105 kt.  The aircraft data have also shown a clear 
indication of concentric eyewalls, which will likely cause 
fluctuations, both up and down, in Lee's intensity over the next day 
or two.

The major hurricane is moving slowly toward the northwest at about 
7 kt.  A continued slow motion between west-northwest and northwest 
is expected during the next couple of days as Lee continues to be 
steered by a mid-level high to its north-northeast. Around the 
middle of the week, the ridge is expected to shift eastward as a 
mid- to upper-level trough amplifies over the eastern U.S.  This 
pattern change should cause Lee to turn northward with an increase 
in forward speed.  The models have generally changed little this 
cycle, and only small changes were made to the previous NHC track 
forecast.  Lee is likely to pass near, but to the west of Bermuda, 
late Thursday and Friday and be situated offshore of the 
mid-Atlantic states and New England by the end of the forecast 
period. 

As mentioned above, fluctuations in strength are likely in the 
short term due to eyewall replacement cycles, but there is an 
opportunity for some strengthening during that time since the 
system is expected to remain over very warm waters and in 
relatively low wind shear conditions.  Beyond a couple of days, 
however, progressively cooler waters and a notable increase in 
shear should cause Lee to gradually weaken.  Although the weakening 
is forecast later in the week, Lee is expected to significantly 
increase in size and hazards will extend well away from the center 
of the storm by the end of the forecast period. 


KEY MESSAGES:

1. Dangerous surf and life-threatening rip currents will affect
portions of the northern Leeward Islands, the Virgin Islands, Puerto
Rico, Hispaniola, the Turks and Caicos Islands, the Bahamas, 
Bermuda, and most of the U.S East Coast through much of the week.

2. Lee could bring strong winds, rainfall, and high surf impacts to
Bermuda later this week. Interests there should monitor the latest
forecasts.

3. It remains too soon to know what level of additional impacts Lee 
might have along the Northeast U.S. coast and Atlantic Canada late 
this week and this weekend, however, wind and rainfall hazards will 
likely extend well away from the center as Lee grows in size. Users 
should continue to monitor updates to the forecast of Lee during the 
next several days.


FORECAST POSITIONS AND MAX WINDS

INIT  11/1500Z 23.5N  63.5W  105 KT 120 MPH
 12H  12/0000Z 23.9N  64.4W  110 KT 125 MPH
 24H  12/1200Z 24.4N  65.5W  115 KT 130 MPH
 36H  13/0000Z 24.9N  66.5W  110 KT 125 MPH
 48H  13/1200Z 25.7N  67.2W  100 KT 115 MPH
 60H  14/0000Z 27.0N  67.7W   95 KT 110 MPH
 72H  14/1200Z 28.8N  68.0W   90 KT 105 MPH
 96H  15/1200Z 33.1N  67.6W   80 KT  90 MPH
120H  16/1200Z 38.9N  67.1W   70 KT  80 MPH

$$
Forecaster Cangialosi

[yoda]

[MANDA]

32 minutes ago, yoda said:

That track would cause moderate to severe beach erosion, tidal flooding and extremely dangerous surf/waves into the Gulf of Maine and on the North and NE facing beaches of Cape Cod ( Boston Harbor as well) as N to NE winds would pound the coast until the center passes a given latitude and winds back into the NW.  If it were to track more on the left side of the cone it of course would be worse but that is not likely at this time.  Sprawling wind field will have plenty fetch to pile up water in advance of the center before it passes.  Expect coastal flood warnings etc. as we move into late week.

[RevWarReenactor]

Looks like the NWS isn't buying the hook west yet, either that or they are downplaying it for now until things get closer.

 

 

 

[GaWx]

For the record 6Z GFS landfall E ME 9/17

[NJwx85]

12 minutes ago, RevWarReenactor said:

Looks like the NWS isn't buying the hook west yet, either that or they are downplaying it for now until things get closer.

 

 

 

New England is within the cone of uncertainty. That should tell you all you need to know.

[Eskimo Joe]

Would bet that we'll have a much better idea of the storm track over the next 24 hours. All of the players will be either over the upper air network in North America or sampled by the hurricane hunters. 

[GaWx]

Trying to keep this going as long as countable in order to follow trend and for record:

 EPS 0Z/12Z US landfalls: two 20%+ in a row 

9/11 0Z: ~12 (24%): ~9 ME, 1 MA, 1 RI, 1 NY

9/10 12Z: 10 (20%): 6 ME, 3 MA, 1 RI

9/10 0Z: 3 (6%): 1 ME, 2 MA

9/9 12Z: 6 (12%) 9/17-19 (3 ME, 3 MA)
9/9 0Z: 3 (6%) 9/17 (3 ME)
9/8 12Z: 5 (10%) 9/15-18 (5 ME) 
9/8 0Z: 7 (14%) 9/15-17 (6 ME, 1 NY)
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)
9/6 12Z: 3 (6%) 9/15-18 (2 ME, 1 MA)
9/6 0Z: 5 (10%)
9/5 12Z: 2 (4%)
9/5 0Z: 4 (8%) 
9/4 12Z: 1 (2%) 
9/4 0Z: 2 (4%)

[GaWx]

For record/trend following purposes, GEFS US landfalls: last 4 runs 26-42% US landfalls

6Z GEFS: ~10 (32%) ~6 ME, 2 MA, 2 RI

Last 12 GEFS runs: 32%, 29%, 26%, 42%, 10%, 13%, 26%, 16%, 16%, 10%, 10%, 10%

[olafminesaw]

Definitely expanding

[Eskimo Joe]

12z OP GFS appears to be into eastern Maine / PEI? The 850/925 low track would suggest some nasty weather from the CT/RI border east.