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Hurricane Lee Discussion Number  26
NWS National Hurricane Center Miami FL       AL132023
500 PM AST Mon Sep 11 2023
 
Lee continues to exhibit a double eyewall structure as reported by 
the Air Force Hurricane Hunters and seen in recent microwave images. 
The inner eyewall is open on the south side, but the outer eyewall 
is completely closed and has contracted slightly from the earlier 
NOAA P-3 aircraft mission.  The minimum pressure is the same as 
before, 948 mb, but the initial wind speed is nudged downward to 100 
kt based on the aircraft data.
 
The major hurricane has jogged a little to the left recently, and 
the initial motion is estimated to be 290/7 kt.  The models are 
similar to the previous runs, and no big changes were made to the 
NHC track forecast. A continued slow motion between west-northwest 
and northwest is expected during the next couple of days as Lee 
remains steered by a mid-level high to its north-northeast. Beyond a 
couple of days, 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.  Lee is likely to pass near, but to the west of 
Bermuda, late Thursday and Friday and then be situated offshore of 
the mid-Atlantic states and New England late Friday and Saturday.
 
Given the current concentric eyewall structure, it seems likely that 
Lee will fluctuate in strength in the short term.  However, since 
the hurricane will remain in generally conducive conditions during 
the next couple of days, it could restrengthen if the eyewall cycle 
completes.  Lee is likely to move over a cool SST wake left behind 
by Hurricanes Idalia and Franklin later this week, and cross over 
the north wall of the Gulf Stream by the end of the forecast period. 
The combination of cooler SSTs, an increase in shear, and dry air 
entrainment should cause a steady decay in strength late this week 
and over the weekend.  The NHC intensity forecast is an update of 
the previous one and near the middle of the guidance envelope.
 
Although Lee is expected to weaken later in the week, it is expected 
to significantly increase in size and hazards will extend well away 
from the storm center 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 continue to monitor 
updates to the forecast of Lee during the next several days.
 
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  11/2100Z 23.6N  64.2W  100 KT 115 MPH
 12H  12/0600Z 24.0N  65.1W  105 KT 120 MPH
 24H  12/1800Z 24.6N  66.1W  105 KT 120 MPH
 36H  13/0600Z 25.3N  66.9W  100 KT 115 MPH
 48H  13/1800Z 26.5N  67.5W  100 KT 115 MPH
 60H  14/0600Z 28.3N  67.8W   95 KT 110 MPH
 72H  14/1800Z 30.3N  67.9W   90 KT 105 MPH
 96H  15/1800Z 35.4N  67.1W   80 KT  90 MPH
120H  16/1800Z 40.8N  67.0W   65 KT  75 MPH
 
$$
Forecaster Cangialosi
 
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