[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT44 KNHC 121449
TCDAT4

Hurricane Margot Discussion Number  21
NWS National Hurricane Center Miami FL       AL142023
300 PM GMT Tue Sep 12 2023

After a brief hiatus, Margot has redevloped a fairly clear eye.
Cloud-top temperatures around that eye are cold enough to support
satellite intensity estimates similar to the previous advisory and
the intensity is held at 75 kt. The big change with this advisory is
that ASCAT data valid between 12 and 13 UTC revealed Margot has
grown substantially, with 34 kt and 50 kt winds extending much
farther from the center of the hurricane than previously estimated.
Microwave data also suggest the presence of a double eyewall.

There is high confidence in the track forecast for the next 3 days.
Margot should turn north-northwestward tomorrow while it slows down.
After that, there is considerable uncertainty in the strength of a
ridge that is forecast to build to the north of Margot. The GFS and
ECMWF are on opposite ends of the spectrum, with the GFS showing
Margot moving faster to the north due to a weaker blocking high.
Confidence in the track forecast decreases at day 4 and 5 given the
high spread. The NHC forecast is near the multi-model consensus, but
relatively large changes could be required to later advisories if
one model solution or another becomes more likely.

The aforementioned ASCAT passes also showed that despite the
relatively small eye of Margot, the wind field is fairly spread
out, which may limit the potential for substantial further
intensification. Most of the hurricane models seem to have a good
handle on this, showing Margot more or less maintaining its
intensity for the next several days. Weakening should begin after
3 days as Margot moves over cooler waters, wind shear increases,
and possibly its transition to an extratropical cyclone begins.


FORECAST POSITIONS AND MAX WINDS

INIT  12/1500Z 30.2N  39.4W   75 KT  85 MPH
 12H  13/0000Z 31.8N  40.0W   80 KT  90 MPH
 24H  13/1200Z 33.3N  41.0W   80 KT  90 MPH
 36H  14/0000Z 34.3N  41.6W   75 KT  85 MPH
 48H  14/1200Z 35.3N  41.6W   75 KT  85 MPH
 60H  15/0000Z 36.3N  41.4W   70 KT  80 MPH
 72H  15/1200Z 37.0N  41.5W   70 KT  80 MPH
 96H  16/1200Z 38.5N  43.0W   55 KT  65 MPH
120H  17/1200Z 40.5N  43.0W   45 KT  50 MPH

$$
Forecaster D. Zelinsky
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