[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT44 KNHC 082036
TCDAT4

Tropical Storm Margot Discussion Number   6
NWS National Hurricane Center Miami FL       AL142023
500 PM AST Fri Sep 08 2023

Margot continues to be a disorganized tropical storm. Over the past
few hours, visible satellite depicts the low-level center has become
exposed with deep convection displaced to the northeast. This deep
convection has continued to persist, however the system has not
become better organized today. An earlier AMSR2 microwave pass
showed that the structure of the system is fairly poor with very
little banding features. Subjective and objective satellite
intensity estimates from SAB/TAFB for this advisory were unchanged
for this cycle. Given the disorganized structure and the satellite
estimates, the initial intensity remains 35 kt for this advisory.

The tropical storm is moving west-northwestward at about 15 kt along
the southern edge of a mid-level ridge.  Margot is expected to
continue this general motion for the next day or so.  Afterwards a
weakness in the ridge will allow for a turn more northwestward, then
northward by early next week.  Overall, models are in fairly good
cross-track agreement in the short term. However beyond day
3, there begins to be some divergence in the model suite, due to
uncertainty in the steering flow. The ECMWF lies on the left side of
the envelope, while the GFS is on the right side.  The official
track forecast is similar to the previous advisory, and lies in the
center of the guidance closest to the HCCA and TVCA consensus aids.

The intensity forecast is fairly difficult given the mixed
environmental conditions. Sea surface temperatures are sufficiently
warm along the forecast track, but vertical wind shear is already
impacting the system and is forecast to remain throughout much of
the forecast period. Given the competing factors and current lack of
organization, the intensity guidance shows only gradual
strengthening throughout the forecast period. The official forecast
is similar to the previous, near the intensity consensus aids the
IVCN and HCCA.


FORECAST POSITIONS AND MAX WINDS

INIT  08/2100Z 18.8N  34.3W   35 KT  40 MPH
 12H  09/0600Z 19.8N  36.3W   40 KT  45 MPH
 24H  09/1800Z 21.0N  38.5W   45 KT  50 MPH
 36H  10/0600Z 22.2N  40.1W   50 KT  60 MPH
 48H  10/1800Z 23.6N  41.0W   55 KT  65 MPH
 60H  11/0600Z 25.1N  41.7W   65 KT  75 MPH
 72H  11/1800Z 26.9N  42.2W   70 KT  80 MPH
 96H  12/1800Z 30.0N  42.6W   75 KT  85 MPH
120H  13/1800Z 33.1N  43.4W   75 KT  85 MPH

$$
Forecaster Kelly
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