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Hurricane Fernanda Discussion Number 9
NWS National Hurricane Center Miami FL EP072023
1100 AM HST Mon Aug 14 2023
Fernanda has been maintaining a well-defined eye some 10 n mi in
diameter with very cold surrounding convective cloud tops. The
upper-level outflow pattern remains well defined, particularly to
the north. Dvorak current intensity estimates from TAFB and SAB
remain at 115 kt and objective ADT estimates from UW-CIMSS are also
near that value. Thus the intensity estimate is held at 115 kt,
i.e. category 4 strength, for this advisory.
Although there have been some trochoidal wobbles in the motion,
which is fairly common in intense hurricanes, the overall motion
continues to be westward or slightly north of westward at a rather
slow pace, 6 kt. The mid-level ridge to the north of Fernanda is
still rather weak due to the influence of a cutoff low near the
California coast. Global model predictions show the ridge becoming
better established over the next several days, which should result
in some increase in forward speed. In 3-5 days, the shallower and
weaker cyclone is likely to be carried on a westward track
following the lower-level trade wind flow. The official forecast
track is basically an extension of the previous one and remains in
good agreement with the simple and corrected dynamical model
consensus solutions.
Although it is likely that Fernanda has reached its peak intensity,
the hurricane should remain in a favorable SST and atmospheric
thermodynamic environment until tonight so some additional
short-term strengthening is possible. After about 12 hours, the
influences of drier air and cooler waters should begin to take their
toll, so the official forecast shows a steady weakening trend in 1-4
days. This is in good agreement with the corrected consensus, HCCA,
prediction.
FORECAST POSITIONS AND MAX WINDS
INIT 14/2100Z 15.9N 119.0W 115 KT 130 MPH
12H 15/0600Z 16.5N 120.3W 120 KT 140 MPH
24H 15/1800Z 17.2N 122.4W 105 KT 120 MPH
36H 16/0600Z 17.5N 124.8W 85 KT 100 MPH
48H 16/1800Z 17.7N 127.5W 70 KT 80 MPH
60H 17/0600Z 17.9N 130.2W 55 KT 65 MPH
72H 17/1800Z 18.0N 133.0W 40 KT 45 MPH
96H 18/1800Z 18.0N 139.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
120H 19/1800Z 18.0N 145.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
$$
Forecaster Pasch
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