Potentially Catastrophic Category 5 Hurricane Lee Still Poses A Grave Long-range Threat

000

WTNT33 KNHC 080251

TCPAT3

BULLETIN

Hurricane Lee Advisory Number  11

NWS National Hurricane Center Miami FL       AL132023

1100 PM AST Thu Sep 07 2023

...LEE BECOMES A CATEGORY 5 HURRICANE...

...DANGEROUS BEACH CONDITIONS EXPECTED TO DEVELOP AROUND THE 

WESTERN ATLANTIC THROUGH EARLY NEXT WEEK...

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

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

LOCATION...17.3N 52.4W

ABOUT 705 MI...1135 KM E OF THE NORTHERN LEEWARD ISLANDS

MAXIMUM SUSTAINED WINDS...160 MPH...260 KM/H

PRESENT MOVEMENT...WNW OR 295 DEGREES AT 14 MPH...22 KM/H

MINIMUM CENTRAL PRESSURE...928 MB...27.41 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 17.3 North, longitude 52.4 West. Lee is moving toward

the west-northwest near 14 mph (22 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 an Air Force Reserve Hurricane Hunter aircraft indicate

that maximum sustained winds have increased to near 160 mph (260

km/h) with higher gusts.  Lee is a category 5 hurricane on the

Saffir-Simpson Hurricane Wind Scale.  Additional strengthening is

forecast overnight.  Fluctuations in intensity are likely over the

next few days, but Lee is expected to remain a major hurricane

through early next week.

Hurricane-force winds extend outward up to 45 miles (75 km) from the

center and tropical-storm-force winds extend outward up to 140 miles

(220 km).

The minimum central pressure based on dropsonde data is 928 mb

(27.41 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 expected to reach portions of the

Lesser Antilles on Friday, and 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

beginning Sunday.  Please consult products from your local weather

office.

NEXT ADVISORY

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

Next complete advisory at 500 AM AST.

$$

Forecaster Berg

939 

WTNT43 KNHC 080252

TCDAT3

Hurricane Lee Discussion Number  11

NWS National Hurricane Center Miami FL       AL132023

1100 PM AST Thu Sep 07 2023

The Air Force Reserve Hurricane Hunters have found that Lee has

skyrocketed to category 5 strength.  The aircraft measured peak

700-mb flight-level winds of 148 kt and trustworthy SFMR winds

slightly over 140 kt, and dropsonde data shows that the minimum

pressure has plummeted to 928 mb.  Based on these data, the initial

intensity is set at 140 kt, and Lee's maximum winds have increased

by an incredible 70 kt over the past 24 hours.  The hurricane has a

clear 15 n mi-wide eye, with an infrared eye temperature as warm

as 21 C surrounded by convective cloud tops as cold as -76 C.

Additional strengthening appears likely, as Lee remains in a

low-shear environment and over very warm waters near 30 degrees

Celsius, and there are no signs of an imminent eyewall replacement.

In fact, based on guidance from UW-CIMSS, the probability of a

secondary eyewall formation during the next 24 hours is well below

climatology.  There is some chance that moderate deep-layer

southwesterly shear could develop over the hurricane, but this

could be offset by strong upper-level divergence and thus have

little to no impact.  To account for the recent rate of

intensification, the NHC intensity forecast is slightly above the

IVCN and HCCA consensus aids and shows a peak intensity of 155 kt in

12 hours.  Amazingly, the 1800 UTC HAFS-A and -B runs show a peak

intensity between 170-180 kt, but that's getting into rarefied air.

The NHC forecast will be adjusted accordingly if those solutions

begin looking like a more distinct possibility.  Only very gradual

weakening is shown after 12-24 hours, and it is likely that Lee's

intensity will fluctuate for much of the forecast period.  Lee is

forecast to remain a dangerous category 4 or 5 hurricane for the

next 5 days.

For the next 5 days--through next Tuesday evening--Lee is expected

to maintain a steady west-northwestward track, passing well to the

north of the northern Leeward Islands, the Virgin Islands, and

Puerto Rico.  The hurricane is currently moving at about 12 kt, but

it is expected to slow down considerably through early next week as

the steering ridge to its north builds southwestward, effectively

blocking Lee's progress.  The NHC track forecast remains of high

confidence through day 5, and again, no significant changes were

required from the previous forecast.  Although there are some

indications that Lee might begin a northward turn around the middle

of next week, it is still way to soon to focus on specific model

scenarios that far out into the future.

KEY MESSAGES:

1. Lee has become a dangerous category 5 hurricane, and further

strengthening is forecast overnight.  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 likely in

the northern Leeward Islands beginning Friday.  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.  Continue to monitor updates to Lee's 

forecast during the next several days.

FORECAST POSITIONS AND MAX WINDS

INIT  08/0300Z 17.3N  52.4W  140 KT 160 MPH

 12H  08/1200Z 18.1N  54.0W  155 KT 180 MPH

 24H  09/0000Z 19.1N  56.1W  150 KT 175 MPH

 36H  09/1200Z 20.1N  58.0W  145 KT 165 MPH

 48H  10/0000Z 20.9N  59.6W  140 KT 160 MPH

 60H  10/1200Z 21.5N  60.9W  135 KT 155 MPH

 72H  11/0000Z 22.1N  62.2W  130 KT 150 MPH

 96H  12/0000Z 23.2N  64.7W  125 KT 145 MPH

120H  13/0000Z 24.1N  66.6W  115 KT 130 MPH

$$

Forecaster Berg