Skip Navigation Links
NOAA NOAA United States Department of Commerce

Hurricane FERNANDA


Hurricane Fernanda Discussion Number  23
NWS National Hurricane Center Miami FL       EP062017
800 AM PDT Mon Jul 17 2017

Fernanda's eye has - once again - become clear in the shortwave
infrared imagery with a slightly asymmetric ring of very cold cloud
tops surrounding the 15 nm eye.  A blend of the subjective Dvorak
fixes from SAB/TAFB along with the objective Advanced Dvorak
Technique gives 110 kt intensity, maintaining Fernanda as a Category
3 hurricane.

In the short term, the SSTs beneath Fernanda will gradually cool,
reaching 26C in about 36 hours.  By days 4 and 5, the vertical shear
should go up substantially due to Fernanda moving closer to a
tropical upper-tropospheric trough.  Thus the official intensity
forecast shows steady weakening with the system becoming a remnant
low around day 5.  This forecast is closest to a blend of the LGEM
and D-SHIPS statistical intensity schemes, as well as the HCCA
corrected consensus technique.  (The HWRF and COAMPS dynamical
models appear to hold on to too strong a system at days 3 and
beyond, based upon the environment that Fernanda is expected to

The hurricane is tracking toward the west-northwest at about 9 kt.
Fernanda is expected to turn slightly toward the northwest during
the next couple of days as it moves around the southwestern
periphery of a deep-layer subtropical ridge.  By days 3 to 5, the
system should turn back toward the west as it gets advected along in
the low-level flow as a weakening tropical cyclone.  The NHC
forecast is nearly unchanged from the previous advisory and is based
upon the TVCN multi-model consensus technique.

The initial wind radii were maintained based on the earlier 0542Z
and 0626Z ASCAT scatterometer overpasses.  The forecast wind radii
are based upon the RVCN multi-model consensus technique.


INIT  17/1500Z 13.7N 130.9W  110 KT 125 MPH
 12H  18/0000Z 14.4N 132.0W  100 KT 115 MPH
 24H  18/1200Z 15.3N 133.3W   90 KT 105 MPH
 36H  19/0000Z 16.1N 134.4W   80 KT  90 MPH
 48H  19/1200Z 16.8N 135.6W   70 KT  80 MPH
 72H  20/1200Z 17.5N 138.9W   50 KT  60 MPH
 96H  21/1200Z 17.9N 142.3W   35 KT  40 MPH
120H  22/1200Z 18.3N 146.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

Forecaster Landsea