[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT45 KNHC 010239
TCDAT5

Tropical Storm Victor Discussion Number   7
NWS National Hurricane Center Miami FL       AL202021
1100 PM AST Thu Sep 30 2021

Satellite imagery shows that Victor has become a little better
organized since the last advisory, with the convective banding
becoming better defined near the center in the northeastern
semicircle.  Recent ASCAT data showed winds of 45-47 kt about 70 n
mi north of the center, and based on the likelihood of some
undersampling the initial intensity is increased to 50 kt.  Although
the scatterometer showed a stronger storm, the data suggested the
system has not yet formed a well-defined inner core.

The initial motion is now 300/10 kt.  Victor is expected to continue
west-northwestward for another 24 h or so on the south side of a
deep-layer ridge over the subtropical eastern Atlantic.  After that
time, a developing mid- to upper-level low over the central Atlantic
is expected to erode the western portion of the ridge.  As a result,
Victor is expected to turn northwestward by the weekend and then
northward by early next week when it is forecast to move in the flow
between the ridge and the low.  The guidance has changed little
since the previous advisory, with the HWRF remaining a significant
outlier to the east.  Thus, the new forecast track is a little to
the west of the various consensus aids that include the HWRF.  The
new forecast is basically an update of the previous forecast.

Victor should remain in a favorable environment for the next 24 h or
so, and the intensity forecast shows more strengthening during that
time,  After that, the upper-level low should cause moderate to
strong southwesterly shear over the storm, and by the end of the
forecast period it will be moving into a drier air mass.  This
combination should cause Victor to steadily weaken after 24 h.  The
new NHC forecast has some adjustments from the previous forecast,
and it now calls for the cyclone to decay to a remnant low by 120 h.
 The intensity forecast lies near the upper edge of the intensity
guidance through 48-60 h, and thereafter is close to the intensity
consensus.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 10.6N  30.7W   50 KT  60 MPH
 12H  01/1200Z 11.3N  32.1W   55 KT  65 MPH
 24H  02/0000Z 12.4N  33.8W   60 KT  70 MPH
 36H  02/1200Z 13.9N  35.2W   55 KT  65 MPH
 48H  03/0000Z 15.5N  36.8W   50 KT  60 MPH
 60H  03/1200Z 17.7N  38.7W   45 KT  50 MPH
 72H  04/0000Z 20.2N  40.4W   40 KT  45 MPH
 96H  05/0000Z 25.0N  43.0W   30 KT  35 MPH
120H  06/0000Z 28.5N  43.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven
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