Tropical Storm LARRY Advisory 9月1日

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Tropical Storm Larry Discussion Number   5
NWS National Hurricane Center Miami FL       AL122021
800 PM CVT Wed Sep 01 2021

Afternoon satellite imagery indicates that Larry continues to
become better organized, with visible imagery hinting at eye
formation and a partial SSM/IS overpass suggesting that a 37 GHz
convective ring is present around the center.  Satellite intensity
estimates are now 65 kt from SAB and 55 kt from TAFB, and the
initial intensity is increased to 60 kt, which is a 30 kt increase
since this time yesterday satisfying the 24-h definition of rapid
intensification.

The initial motion is now 275/19 kt.  Larry is expected to move
around the south and southwest sides of a subtropical ridge during
the next five days, with a general westward motion for 24-36 h,
followed by a turn toward the west-northwest and, by 96-120 h, a
turn toward the northwest.  The spread in the track guidance after
36 h has decreased a little in the latest model runs.  However, the
guidance envelope has again shifted a little to the west.  The new
forecast track will also be shifted a little westward, and it lies
on the southern edge of the various consensus models.

Conditions appear favorable for additional rapid intensification
during at the next 36-48 h, and the intensity forecast now calls for
Larry to become a hurricane in less than 12 h and become a major
hurricane in about 48 h.  Given current trends, this part of the
intensity forecast could be conservative.  There is lower confidence
in the intensity forecast after 48 h.  Larry is expected to
encounter somewhat increased shear, and around the 72 h point it is
expected to encounter some dry air.  After 96 h, moderate shear is
forecast to continue, but the cyclone is expected to move into a
more moist air mass and over increasing sea surface temperatures.
On top of these factors, there is the good chance that Larry will
have fluctuations in intensity after it becomes a major hurricane
due to eyewall replacement cycles.  The intensity guidance basically
keeps a steady intensity from 60-120 h, and the official forecast
follows that trend.  However, this part of the intensity forecast is
in the middle of the guidance, and it is possible Larry could be
stronger than forecast during this time.


FORECAST POSITIONS AND MAX WINDS

INIT  01/2100Z 12.5N  29.4W   60 KT  70 MPH
 12H  02/0600Z 12.6N  31.8W   70 KT  80 MPH
 24H  02/1800Z 13.0N  34.9W   85 KT 100 MPH
 36H  03/0600Z 13.7N  38.0W   95 KT 110 MPH
 48H  03/1800Z 14.6N  40.9W  100 KT 115 MPH
 60H  04/0600Z 15.6N  43.5W  105 KT 120 MPH
 72H  04/1800Z 16.9N  46.2W  105 KT 120 MPH
 96H  05/1800Z 19.5N  50.5W  105 KT 120 MPH
120H  06/1800Z 22.5N  54.0W  105 KT 120 MPH

$$
Forecaster Beven