000
WTPZ41 KNHC 180240
TCDEP1

Hurricane Fernanda Discussion Number  25
NWS National Hurricane Center Miami FL       EP062017
800 PM PDT Mon Jul 17 2017

Conventional satellite and two earlier GMI and GCOM-W1 microwave
images indicate partial erosion in the southeast quadrant of the
eyewall. Inner core cloud top temperatures have warmed, particularly
over the aforementioned quadrant and in the western portion.  A
blend of the subjective and objective Dvorak estimates yields a
lowered initial intensity of 95 kt for this advisory.  Continued
gradual weakening is forecast through the forecast period due to the
cyclone traversing cooler oceanic SSTs and moving into a more stable
and drier air mass with increasing vertical shear.  The official
forecast has been adjusted down a bit from the previous forecast
based on the lowered initial intensity and follows the IVCN
multi-model consensus.

The initial motion is estimated to be northwestward, or 310/8 kt.
Global models show a large amplitude mid- to upper-level
tropospheric trough situated to the northeast of the Hawaiian
Islands lifting northeastward around the 48-hour period,
allowing the subtropical ridge to the north of Fernanda to rebuild
westward.  This change in the synoptic steering pattern should
cause the cyclone to turn back toward the west-northwest and
continue in this motion through day 5.  The NHC forecast track is
adjusted to the right of the previous advisory beyond day 3 and is
in between the GFS/ECMWF blend and the TVCN consensus.


FORECAST POSITIONS AND MAX WINDS

INIT  18/0300Z 14.7N 132.2W   95 KT 110 MPH
 12H  18/1200Z 15.4N 133.1W   85 KT 100 MPH
 24H  19/0000Z 16.2N 134.2W   75 KT  85 MPH
 36H  19/1200Z 16.9N 135.4W   70 KT  80 MPH
 48H  20/0000Z 17.3N 136.7W   65 KT  75 MPH
 72H  21/0000Z 18.0N 139.8W   50 KT  60 MPH
 96H  22/0000Z 18.6N 142.7W   35 KT  40 MPH
120H  23/0000Z 19.3N 146.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Roberts