WTPA45 PHFO 310251
TCDCP5

HURRICANE MADELINE DISCUSSION NUMBER  18
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP142016
500 PM HST TUE AUG 30 2016
 
Under the presence of continued vertical wind shear, the satellite
presentation of Madeline has continued to gradually degrade today,
as an eye is no longer present. While Dvorak final T numbers
continue to drop, current intensity estimates range from 5.5/102 kt
at HFO to 5.0/90 kt out of JTWC and SAB, and CIMSS ADT has fallen
below 80 kt. Since Air Force reconnaissance aircraft reported
stronger than expected winds earlier in the day, the current
intensity will be set at 95 kt for this advisory. The Air Force
reconnaissance aircraft will fly another mission in Madeline this
evening.
 
The initial motion for this advisory remains due west at 270/09 kt.
Madeline continues to move westward along the southern edge of a low
to mid level ridge, while a shallow upper level trough continues to
dig toward the hurricane from the northwest. The ridge will keep
Madeline on a westward-moving track into the evening, followed by a
gradual turn toward the west-southwest tonight and Wednesday as the
mid level ridge strengthens to the north and northwest and the upper
level trough imparts northwesterly winds in the high levels of the
cyclone. This track will take the center of Madeline dangerously
close to the Big Island of Hawaii (Hawaii County) late Wednesday
into Thursday, and a Hurricane Warning remains in place for the Big
Island, given the very close approach of Madeline and uncertainty in
the track forecast. On Friday Madeline is forecast to turn back
toward the west as the upper level trough digs southward over
Hawaii. The official forecast track has changed little from the
prior advisory and is near TVCN, which lies in the middle of a
rather tightly clustered reliable guidance envelope during the next
three days. The guidance envelope spreads beyond day three, while
the GFDL remains the northern outlier through the entire forecast
duration.
 
Madeline is expected to gradually weaken through the next four days
as the upper level trough digs southward and continues to impart
vertical wind shear. UW CIMSS estimates current vertical wind shear
from the west-southwest at 14 kt, and SHIPS forecasts shear to
gradually increase during the next 24 to 36 hours before relaxing
on Friday. The official intensity forecast calls for gradual
weakening during this time that follows the trends of SHIPS and
IVCN, though at a slightly slower rate of weakening than the
guidance through Friday. Although it will be weakening, Madeline is
expected to remain a dangerous hurricane as it passes near the Big
Island of Hawaii late Wednesday into early Thursday.
 
We would like to remind everyone that hazards associated with
hurricanes can extend well away from the center, and you should
not focus too closely on the exact forecast track, as small changes
can lead to differences in impacts.
 
 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  31/0300Z 19.3N 150.3W   95 KT 110 MPH
 12H  31/1200Z 19.1N 151.8W   85 KT 100 MPH
 24H  01/0000Z 18.7N 153.8W   80 KT  90 MPH
 36H  01/1200Z 18.3N 155.7W   70 KT  80 MPH
 48H  02/0000Z 18.1N 157.8W   65 KT  75 MPH
 72H  03/0000Z 18.2N 162.7W   60 KT  70 MPH
 96H  04/0000Z 18.7N 168.2W   55 KT  65 MPH
120H  05/0000Z 19.0N 173.2W   55 KT  65 MPH
 
$$
Forecaster Wroe