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Tropical Depression Eleven-E Discussion Number 2
NWS National Hurricane Center Miami FL EP112018
1000 PM CDT Sat Aug 04 2018
After having a somewhat impressive satellite presentation earlier
today, the final GOES-16 visible images showed what appeared to be
the cyclone's low-level center popping out from the northwestern
edge of the convective canopy. Since that time, the remaining
convection south and east of the center has become less organized,
apparently due to enhanced wind shear associated with a linear band
of convection to the northwest of the cyclone.
This structural degradation of the system further complicates what
was already a low-confidence forecast due to the depression
interacting with the developing system located to its west. The 18Z
GFS doesn't have much of a representation of the depression, and it
is quickly lost in the model integration. The latest HWRF fields
show the vortex being absorbed into the circulation of the
disturbance to the west after 24 hours, and the HMON shows the
system dissipating in 2 to 3 days. On the other hand, the 12Z
runs of the ECMWF and UKMET maintain the depression into days 4 and
5, respectively. In an effort to maintain some continuity with the
previous forecast while acknowledging the current trends, the new
intensity forecast still shows some strengthening but at a slower
rate given that the upper-level winds appear to be winning out so
far over the warm SSTs. The official forecast carries the tropical
cyclone through 72 hours with dissipation shown at day 4, but it
would not be surprising if the cyclone dissipated much sooner than
indicated here.
The initial motion estimate is a somewhat more confident 295/10
given that the center was exposed right around 00Z. The track
forecast reasoning has not changed, as the small cyclone should be
steered west-northwestward by a large ridge to its north and the
aforementioned disturbance to the west, which the model guidance
suggests will strengthen quickly during the next couple of days.
The new NHC forecast is a bit to the right of the previous one and
is close to a blend of the ECMWF and UKMET models.
Based on the forecast, any tropical-storm-force winds are expected
to remain offshore the coast of Mexico. However, given the low
confidence in both the track and intensity of the depression,
interests along the southern and southwestern coast of Mexico should
monitor its progress in case the track shifts closer to the coast or
the cyclone strengthens and grows larger than forecast.
FORECAST POSITIONS AND MAX WINDS
INIT 05/0300Z 13.0N 95.9W 25 KT 30 MPH
12H 05/1200Z 13.4N 97.3W 25 KT 30 MPH
24H 06/0000Z 14.2N 99.4W 30 KT 35 MPH
36H 06/1200Z 15.1N 101.5W 35 KT 40 MPH
48H 07/0000Z 16.3N 103.8W 40 KT 45 MPH
72H 08/0000Z 19.0N 109.5W 40 KT 45 MPH
96H 09/0000Z...DISSIPATED
$$
Forecaster Brennan
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