[Tropical] Tropical Cyclone Discussion

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WTNT44 KNHC 130833
TCDAT4

Tropical Storm Sean Discussion Number  10
NWS National Hurricane Center Miami FL       AL192023
500 AM AST Fri Oct 13 2023

Moderate westerly deep-layer shear continues over Sean this morning,
and most of the associated deep convection is displaced to the east
of Sean's center. Although the low-level circulation remains at
least partially exposed in proxy-visible satellite images, new
bursts of deep convection have recently developed closer to the
center of Sean. It remains to be seen whether this activity will be
persistent enough to support any additional strengthening. The
latest objective and subjective satellite intensity estimates range
from 30-45 kt, and a blend of these data support keeping the initial
intensity at 40 kt.

Sean is moving west-northwestward (285 degrees) at 11 kt. The
general track forecast reasoning has not changed. Sean should move
west-northwestward to northwestward over the next few days while
being steered by a weak subtropical ridge over the eastern and
central Atlantic. There are no significant changes noted in the
latest track guidance. The updated NHC forecast lies slightly to the
left of the previous prediction, primarily the result of a more
west-northwestward initial motion based on recent center fixes.

The various global and regional models suggest Sean is likely near
or at its peak intensity. Although the shear could weaken some
during the next couple of days, the convective structure of Sean is
unlikely to improve much while the storm gains latitude and moves
into a drier, more stable environment. The NHC forecast continues to
show gradual weakening during the next few days, in good agreement
with the latest multi-model consensus aids. The global models show
an even faster rate of weakening, as the system becomes devoid of
organized convection by early next week in both GFS and ECMWF
model-simulated satellite imagery. Sean is still forecast to open
into a trough and dissipate between 72-96 h.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0900Z 14.3N  40.5W   40 KT  45 MPH
 12H  13/1800Z 15.1N  41.6W   40 KT  45 MPH
 24H  14/0600Z 16.4N  42.9W   35 KT  40 MPH
 36H  14/1800Z 17.6N  44.2W   35 KT  40 MPH
 48H  15/0600Z 18.4N  45.3W   30 KT  35 MPH
 60H  15/1800Z 19.2N  46.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  16/0600Z 19.7N  47.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  17/0600Z...DISSIPATED

$$
Forecaster Reinhart
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