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Hurricane Larry Discussion Number  20
NWS National Hurricane Center Miami FL       AL122021
1100 AM AST Sun Sep 05 2021
 
Larry continues as a large and intense hurricane this morning, with 
a 40 n mi diameter eye surround by cloud tops to near -80 deg C. 
There are, however, some breaks in the cold tops over the northern 
portion of the circulation.  The current intensity is adjusted 
slightly to 110 kt, based on a blend of subjective Dvorak estimates 
from TAFB and SAB along with objective ADT estimates from UW-CIMSS. 
Upper-level outflow remains somewhat restricted over the 
southwestern quadrant of the system, indicative of at least slight 
vertical shear.  This shear is probably being caused by the flow to 
the east of an upper-level low to the north of Puerto Rico. The low 
is forecast to move northwestward over the next few days, possibly 
lessening the shear over Larry.
 
The hurricane is moving northwestward at a slightly slower speed, or 
310/11 kt.  Larry is likely to continue its northwestward trek 
along the southwestern periphery of a mid-tropospheric anticyclone 
during the next 2-3 days, with only a slight reduction in forward 
speed.  Around 96 hours, the hurricane is forecast to turn toward 
the north-northwest and north while rounding the western side of 
the ridge.  By the end of the forecast period, Larry is expected to 
begin its recurvature into the mid-latitude westerlies.  The new 
official forecast track essentially follows the previous one, and is 
also very close to the latest NOAA corrected consensus and Florida 
State University Superensemble guidance.
 
Larry's large eye suggests that no rapid changes in strength are
likely during the short term.  Since vertical shear is not expected 
to increase and the system will be traversing warm waters, the 
hurricane should be able to more or less maintain its intensity 
during the next few days.  One inhibiting factor is the presence of 
relatively dry mid-level air in the environment.  The official 
intensity forecast is on the high side of the model guidance and 
keeps Larry as a major hurricane through 72 hours.
 
 
Key Messages:
 
1. Large swells generated by Larry are expected to reach the Lesser
Antilles today and will spread to portions of the Greater Antilles,
the Bahamas, and Bermuda on Monday and Tuesday.  Significant swells
will likely reach the east coast of the United States and Atlantic
Canada by midweek.  These swells will likely cause life-threatening
surf and rip current conditions, and beachgoers and other interests
along these coasts are urged to follow the advice of lifeguards and
local officials this week.
 
2. Larry is forecast to approach Bermuda during the next several
days, likely as a major hurricane, bringing a risk of strong
winds, heavy rainfall, and coastal flooding to the island by the
middle of this week.  While it is too soon to determine the
magnitude of these hazards and potential impacts on Bermuda,
interests there should closely monitor the latest forecast updates
during the next several days.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  05/1500Z 19.5N  49.7W  110 KT 125 MPH
 12H  06/0000Z 20.5N  51.1W  110 KT 125 MPH
 24H  06/1200Z 21.9N  52.7W  110 KT 125 MPH
 36H  07/0000Z 23.0N  54.0W  110 KT 125 MPH
 48H  07/1200Z 24.3N  55.4W  105 KT 120 MPH
 60H  08/0000Z 25.7N  56.7W  105 KT 120 MPH
 72H  08/1200Z 27.3N  58.1W  105 KT 120 MPH
 96H  09/1200Z 31.1N  61.1W   95 KT 110 MPH
120H  10/1200Z 37.4N  60.6W   85 KT 100 MPH
 
$$
Forecaster Pasch
 
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