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142
WTPZ45 KNHC 022041
TCDEP5

Hurricane Hector Discussion Number 9
NWS National Hurricane Center Miami FL EP102018
200 PM PDT Thu Aug 02 2018

Hector is a small but powerful hurricane this afternoon. Visible
GOES-15 data show that it has a 10 n mi wide eye, surrounded by a
increasingly symmetric area of deep convection. The latest
satellite estimates at 18 UTC were between 90 kt and 95 kt, and
since the presentation has continued to improve during the past few
hours, the initial wind speed is set to 95 kt.

Hector has intensified an impressive 50 kt over the past 24 hours-
remarkable since the environment did not seem particularly
favorable even 12 hours ago. What is perplexing about this forecast
is that, despite all of the global models showing a more conducive
environment during the next day or two, none of the regional
hurricane models show intensification, and in fact they all show
weakening. This would be a dramatic change, which seems pretty
unlikely given the current state of things. It makes the most sense
to show continuing strengthening, albeit at a reduced rate since the
SSTs do moderate, in line with the SHIPS & LGEM models. The new
forecast has a peak intensity at 72 hours when SSTs are the warmest
with the lowest environmental shear. After that time, water
temperatures and mid-level humidites should gradually decrease,
which will probably promote some weakening. Obviously this is a low
confidence forecast, and I wouldn't be surprised if it had to be
raised in the short term later tonight.

Hector continues on course, moving westward at 12 kt. The track
forecast for the next 3 days is of high confidence, since the
guidance is in good agreement and a large subtropical ridge is
providing a well-defined steering current. Complications arise in
the long range due to the potential interaction of Hector with a
mid-level trough in the Central Pacific. The latest models show
Hector moving into a weakness in the ridge associated with the
trough, causing a more west-northwestward motion earlier in the
forecast. This is a fairly subtle change but has led to most of
the guidance trending to the north. The official forecast is
shifted in that direction, but remains on the southwest side of the
guidance envelope, close to the corrected-consensus models.


FORECAST POSITIONS AND MAX WINDS

INIT 02/2100Z 14.1N 125.8W 95 KT 110 MPH
12H 03/0600Z 14.0N 127.6W 100 KT 115 MPH
24H 03/1800Z 13.9N 129.8W 105 KT 120 MPH
36H 04/0600Z 13.9N 132.0W 105 KT 120 MPH
48H 04/1800Z 13.8N 134.3W 105 KT 120 MPH
72H 05/1800Z 13.6N 139.0W 115 KT 130 MPH
96H 06/1800Z 14.5N 144.0W 110 KT 125 MPH
120H 07/1800Z 15.5N 149.0W 105 KT 120 MPH