Intense Hurricane Lee (Now A Category 3) Could Take Aim At Nova Scotia In The Long-range

224 

WTNT33 KNHC 090239

TCPAT3

BULLETIN

Hurricane Lee Advisory Number  15

NWS National Hurricane Center Miami FL       AL132023

1100 PM AST Fri Sep 08 2023

...AIR FORCE RESERVE AND NOAA HURRICANE HUNTERS FIND LEE NOT AS

STRONG BUT STILL A MAJOR HURRICANE...

...HAZARDOUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE WESTERN

ATLANTIC THROUGH NEXT WEEK...

SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION

-----------------------------------------------

LOCATION...19.3N 56.5W

ABOUT 440 MI...705 KM E OF THE NORTHERN LEEWARD ISLANDS

MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H

PRESENT MOVEMENT...WNW OR 300 DEGREES AT 13 MPH...20 KM/H

MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES

WATCHES AND WARNINGS

--------------------

There are no coastal watches or warnings in effect.

DISCUSSION AND OUTLOOK

----------------------

At 1100 PM AST (0300 UTC), the center of Hurricane Lee was located

near latitude 19.3 North, longitude 56.5 West.  Lee is moving toward

the west-northwest near 13 mph (20 km/h), and this motion is

expected to continue through early next week with a significant

decrease in forward speed.  On the forecast track, Lee is expected

to pass well to the north of the northern Leeward Islands, the

Virgin Islands, and Puerto Rico over the weekend and into early

next week.

Data from Air Force Reserve and NOAA Hurricane Hunter aircraft 

indicate that maximum sustained winds have decreased to near 115 

mph (185 km/h) with higher gusts.  Lee is a category 3 hurricane on 

the Saffir-Simpson Hurricane Wind Scale.  Fluctuations in intensity 

are likely over the next few days, however Lee is expected to remain 

a powerful hurricane through early next week.

Hurricane-force winds extend outward up to 30 miles (45 km) from the

center and tropical-storm-force winds extend outward up to 175 miles

(280 km).

The estimated minimum central pressure is 963 mb (28.44 inches).

HAZARDS AFFECTING LAND

----------------------

Key messages for Lee can be found in the Tropical Cyclone Discussion

under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC and on the

web at hurricanes.gov/text/MIATCDAT3.shtml

SURF:  Swells generated by Lee are affecting portions of the Lesser

Antilles, and will reach the British and U.S. Virgin Islands, Puerto

Rico, Hispaniola, the Turks and Caicos Islands, the Bahamas, and

Bermuda this weekend. These swells are likely to cause

life-threatening surf and rip current conditions.  Dangerous surf

and rip currents are expected to begin along most of the U.S. East

Coast Sunday and Monday and worsen through the week.  Please

consult products from your local weather office.

NEXT ADVISORY

-------------

Next complete advisory at 500 AM AST.

$$

Forecaster Berg

000

WTNT43 KNHC 090240

TCDAT3

Hurricane Lee Discussion Number  15

NWS National Hurricane Center Miami FL       AL132023

1100 PM AST Fri Sep 08 2023

Strong southwesterly shear has taken a toll on Lee's structure.

The crews of ongoing NOAA and Air Force Reserve Hurricane Hunter

missions reported that the hurricane's eyewall has opened up, and

the satellite presentation has degraded significantly since earlier

today.  Both planes have found the minimum pressure rising during 

their missions, with the latest measurements being around 963 mb.  

Based on this pressure and the planes' wind measurements, Lee's 

initial intensity is set at 100 kt.  

Moderate-to-strong deep-layer southwesterly shear is expected to 

continue for at least the next 24 hours, if not longer.  The GFS 

model is the quickest to show the shear abating, but the ECMWF 

now maintains shear over Lee for much of the forecast period.  Most

of the intensity guidance shows Lee weakening further during the 

next 12-24 hours while the shear is at its strongest, and that is 

shown in the new NHC forecast.  Despite the uncertainty in how 

the upper-level pattern, and hence the shear profile, will evolve 

around Lee, it is assumed that the atmospheric environment will 

become at least a little more conducive for restrengthening after 

24 hours.  The NHC intensity forecast blends the latest IVCN 

and HCCA consensus models with the previous official forecast, 

particularly after 48 hours.  Confidence in the intensity forecast 

is low at the moment, although it is likely that Lee will remain a 

dangerous hurricane for at least the next 5 days.

Lee's heading and speed remain 300 degrees at 11 kt.  The 

mid-tropospheric ridge to the north of the hurricane is forecast to 

build to the west and southwest during the next few days, which 

will keep Lee on a west-northwestward course with a decrease in 

speed through next Tuesday.  By Wednesday, a deep-layer trough is 

forecast to amplify over the eastern United States, erode the 

ridge, and cause Lee to gradually turn toward the northwest.  

Although the track models agree on this general scenario, there is 

disagreement on how far west Lee will get before it makes the turn. 

To account for the latest suite of models, the NHC track forecast 

has been shifted slightly westward on days 3 through 5, close to 

the consensus aids but not as far west as the ECMWF, UKMET, and the 

GEFS ensemble mean. 

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

will spread westward and northward, affecting Puerto Rico,

Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda

through the weekend.

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  09/0300Z 19.3N  56.5W  100 KT 115 MPH

 12H  09/1200Z 20.0N  57.8W   95 KT 110 MPH

 24H  10/0000Z 20.8N  59.4W   95 KT 110 MPH

 36H  10/1200Z 21.5N  60.8W  105 KT 120 MPH

 48H  11/0000Z 22.0N  62.0W  115 KT 130 MPH

 60H  11/1200Z 22.5N  63.2W  120 KT 140 MPH

 72H  12/0000Z 22.8N  64.2W  120 KT 140 MPH

 96H  13/0000Z 23.5N  66.4W  120 KT 140 MPH

120H  14/0000Z 25.3N  67.7W  105 KT 120 MPH

$$

Forecaster Berg