000
WTPZ41 KNHC 062035
TCDEP1

Hurricane Sergio Discussion Number  30
NWS National Hurricane Center Miami FL       EP212018
200 PM PDT Sat Oct 06 2018

There has been little change in Sergio's satellite presentation
today.  The large eye remains well defined in visible and infrared
satellite imagery, but there has been a slight warming of the
surrounding cloud tops since this morning.  However, the latest
subjective and objective satellite intensity estimates still support
an initial wind speed of 110 kt.  As mentioned in the previous
discussion, the primary factor regarding Sergio's future intensity
will be ocean temperatures beneath the cyclone over the next few
days, since the other environmental conditions are expected to
remain favorable. Sergio should remain over warm waters during the
next day or so, but some upwelling of cooler water is possible as
Sergio slows down and makes its predicted sharp turn Sunday night
and Monday, and this is forecast to cause some gradual weakening
during that time.  After 72 hours, cooler waters, increasing
southwesterly shear, and less favorable thermodynamic conditions are
likely to result in additional weakening.  The NHC intensity
forecast lies between the higher statistical guidance and the
consensus aids, and is very similar to the previous advisory.

Sergio is moving west-southwestward at about 6 kt.  The hurricane
should turn westward tonight before making a sharp northeastward
turn as a mid-level trough drops southward to the north of Sergio
and erodes the western portion of the ridge.  By early next week,
Sergio should move northeastward ahead of the aforementioned trough.
The track guidance is in good agreement on the overall scenario but
there continues to be differences in the future forward speed of the
hurricane.  The guidance has once again trended a little slower this
cycle, and the new NHC track lies between the previous forecast and
the latest consensus models.

FORECAST POSITIONS AND MAX WINDS

INIT  06/2100Z 14.6N 124.7W  110 KT 125 MPH
 12H  07/0600Z 14.5N 125.7W  110 KT 125 MPH
 24H  07/1800Z 14.6N 126.9W  105 KT 120 MPH
 36H  08/0600Z 15.1N 127.4W  100 KT 115 MPH
 48H  08/1800Z 15.7N 127.4W   90 KT 105 MPH
 72H  09/1800Z 17.5N 125.6W   80 KT  90 MPH
 96H  10/1800Z 20.0N 121.8W   70 KT  80 MPH
120H  11/1800Z 24.2N 116.5W   50 KT  60 MPH

$$
Forecaster Brown