Intense Hurricane Lee (Now A Category 2) Could Take Aim At Nova Scotia In The Long-range Update One

000

WTNT33 KNHC 100241

TCPAT3

BULLETIN

Hurricane Lee Advisory Number  19

NWS National Hurricane Center Miami FL       AL132023

1100 PM AST Sat Sep 09 2023

...LEE EXPECTED TO GROW IN SIZE OVER THE NEXT FEW DAYS...

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

ATLANTIC OVER THE UPCOMING WEEK...

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

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

LOCATION...21.0N 59.9W

ABOUT 285 MI...455 KM NE OF THE NORTHERN LEEWARD ISLANDS

MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H

PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/H

MINIMUM CENTRAL PRESSURE...962 MB...28.41 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 21.0 North, longitude 59.9 West. Lee is moving toward 

the west-northwest near 9 mph (15 km/h). A slower west-northwestward 

motion is expected during the next few days. On the forecast track, 

Lee is expected to pass well north of the northern Leeward Islands, 

the Virgin Islands, and Puerto Rico into early next week.

Maximum sustained winds are near 105 mph (165 km/h) with higher 

gusts. Restrengthening is anticipated over the next day or two.

Hurricane-force winds extend outward up to 35 miles (55 km) from the 

center and tropical-storm-force winds extend outward up to 185 miles 

(295 km). NOAA buoy 40144 located about 90 miles east-northeast of 

the center of Lee reported a peak sustained wind of 52 mph (83 

km/h) with a gust to 60 mph (98 km/h) within the past couple of 

hours.

The minimum central pressure measured by the NOAA hurricane hunter 

aircraft is 962 mb (28.41 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 affecting portions of the Lesser

Antilles, and are spreading westward to the British and U.S. Virgin

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

Bahamas, and Bermuda over the remainder of 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 tomorrow and worsen through next

week. Please consult products from your local weather office.

NEXT ADVISORY

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

Next complete advisory at 500 AM AST.

$$

Forecaster Papin

000

WTNT43 KNHC 100247

TCDAT3

Hurricane Lee Discussion Number  19

NWS National Hurricane Center Miami FL       AL132023

1100 PM AST Sat Sep 09 2023

While the geostationary satellite appearance of Lee has not changed 

appreciably since the prior advisory, data from a NOAA P-3 

reconnaissance mission in the storm, in addition to earlier GPM and 

SSMIS microwave imagery, indicate that Lee is in the middle of an 

eyewall replacement cycle (ERC). The aircraft has been reporting 

both an inner and outer eyewall, with the outer eyewall gradually 

contracting in size. However, this outer eyewall continues to 

exhibit some asymmetry, consistent with modest vertical wind shear 

still affecting the storm. In addition, the aircraft has reported 

that the inner-core wind field is becoming weaker, but broader, with 

a more muted wind profile outside of the radius of maximum wind. 

This observation is also evident comparing TDR data between the 

morning and evening NOAA-P3 missions. The peak 700 mb flight level 

winds were down to 94 kt, with SFMR only in the 75-85 kt range. The 

initial intensity has been adjusted to a somewhat generous 90 kt for 

this advisory.  

Lee continues to move west-northwestward this evening at 300/9 kt. 

As discussed previously, the mid-level ridge axis currently north of 

Lee is soon expected to shift to its west-southwest, resulting in 

Lee slowing its forward motion, and perhaps making a slight westward 

bend over the next 24-36 hours. Afterwards, an eastward-moving 

mid-latitude trough is expected to erode this ridge and allow Lee to 

turn northward by the end of the forecast period. There remains a 

significant amount of spread in both the deterministic and ensemble 

guidance on when this turn occurs, and then how quickly Lee 

accelerates northward. For now the NHC track forecast remains 

closest to the consensus aids, which have slowed a bit from the 

prior cycle, and the latest track forecast is a bit slower but near 

the same trajectory as the prior advisory. 

While vertical wind shear over Lee appears to be gradual decreasing 

over the system, the ongoing ERC seems to be resulting in the wind 

field broadening versus allowing Lee to re-intensify so far. 

However, once this cycle is complete, reintensification is still 

anticipated, and the NHC intensity forecast still takes Lee back to 

a category 4 hurricane in 36-48 hours, in good agreement with the 

latest HAFS-A/B forecasts, which both explicitly show the ongoing 

ERC. However, Lee's growing wind field, in combination with its 

slowing forward motion, could make the hurricane susceptible to 

feeling the effects of its own cold wake, which the 

atmospheric-ocean coupled HAFS and HWRF models suggest could begin 

to occur beyond 36 hours. Thus, the latest NHC intensity forecast 

shows gradual weakening beginning by that time, with more pronounced 

weakening by the end of the forecast period as the hurricane 

traverses already cooled sea-surface temperatures from Franklin and 

Idalia last week along its forecast track. This intensity forecast 

is in good agreement with the simple consensus aids, but is a little 

lower than the HFIP corrected consensus early on.

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 are

spreading westward and northward and will affect Puerto Rico,

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

the next several days.

3. It remains 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, especially 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 tomorrow and continuing into next week 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  10/0300Z 21.0N  59.9W   90 KT 105 MPH

 12H  10/1200Z 21.6N  60.9W  100 KT 115 MPH

 24H  11/0000Z 22.4N  62.3W  110 KT 125 MPH

 36H  11/1200Z 23.0N  63.5W  120 KT 140 MPH

 48H  12/0000Z 23.3N  64.7W  115 KT 130 MPH

 60H  12/1200Z 23.6N  65.6W  110 KT 125 MPH

 72H  13/0000Z 24.0N  66.6W  105 KT 120 MPH

 96H  14/0000Z 25.6N  68.0W   95 KT 110 MPH

120H  15/0000Z 28.8N  68.3W   85 KT 100 MPH

$$

Forecaster Papin