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Hurricane Dora Discussion Number  23
NWS National Hurricane Center Miami FL       EP052023
500 PM HST Sat Aug 05 2023
 
Dora has acquired annular traits, highlighted by a circular and 
relatively large eye (compared to the size of the hurricane itself), 
a wide band of very cold cloud tops within the CDO, and dissolving 
outer bands around the periphery of the circulation.  As a 
reflection of this, the Annular Hurricane Index (AHI) has increased 
to about 85 out of 100.  The maximum winds are now estimated to be 
125 kt, which best matches a Dvorak estimate of T6.5/127 kt from SAB 
and objective ADT and AiDT numbers of 123-125 kt.
 
There's no new news to report regarding Dora's forecast track.  A
ridge building westward to the north of the hurricane is expected
to push Dora faster toward the west while it passes well south of
Hawaii in the next 2-4 days.  The track guidance--and the NHC
official forecast--have been remarkably steady for the past few
days, and the new forecast is basically an update of the previous
prediction.
 
Fluctuations in intensity are possible during the next 6-12 hours
while Dora becomes increasingly annular.  The hurricane is forecast
to continue moving nearly parallel to the sea surface temperature
gradient, over waters of 26-27C for the next several days.
Deep-layer shear is expected to remain light, although Dora is
likely to move into a drier, more subsident environment into early
next week.  That said, annular hurricanes have a proclivity for
weakening more slowly than expected or suggested by intensity
models, and the new NHC forecast therefore lies near the upper
bound of the available guidance, showing only gradual weakening
through the 5-day forecast period.  This forecast is closest to the 
SHIPS guidance during the first couple of days, and then trends 
close to the HCCA and IVCN consensus aids thereafter.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/0300Z 13.2N 136.5W  125 KT 145 MPH
 12H  06/1200Z 13.0N 139.0W  125 KT 145 MPH
 24H  07/0000Z 12.8N 142.7W  120 KT 140 MPH
 36H  07/1200Z 12.5N 146.4W  110 KT 125 MPH
 48H  08/0000Z 12.4N 150.2W  100 KT 115 MPH
 60H  08/1200Z 12.3N 154.0W   95 KT 110 MPH
 72H  09/0000Z 12.4N 157.7W   90 KT 105 MPH
 96H  10/0000Z 12.9N 165.6W   80 KT  90 MPH
120H  11/0000Z 14.1N 173.1W   75 KT  85 MPH
 
$$
Forecaster Berg
 
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