Central Pacific Basin Tropical Cyclones

Hurricane Dora Forecast Discussion

WTPA42 PHFO 071434

Hurricane Dora Discussion Number  29
NWS Central Pacific Hurricane Center Honolulu HI   EP052023
500 AM HST Mon Aug 07 2023

The satellite presentation of Dora has degraded some overnight 
with the convective ring of cold dense overcast warming slightly. 
This is likely due to the ingestion of some drier mid-level air and 
possibly going through an eyewall replacement cycle. The latest 
subjective Dvorak current intensity estimates from PHFO, SAB, and 
JTWC came in at 6.0 (115 kt), 6.5 (127 kt), 6.0 (115 kt) 
respectively, while the objective Dvorak ADT and AiDT estimates from 
UW-CIMSS were 105 kt and 109 kt. Using a blend of these data, the 
initial intensity is lowered to 115 kt with this advisory.

Dora is moving slightly south of due west at 20 kt. This general 
motion is expected to continue during the next several days as a 
deep layer ridge builds to the north of the Hawaiian Islands. A turn 
to the northwest is forecast beyond day 3 as the tropical cyclone 
rounds the southwestern periphery of the deep layer subtropical 
ridge to the north of Hawaii. On this forecast track, Dora is 
expected to move into the western Pacific basin late this week. The 
forecast track is virtually a carbon copy of the previous advisory 
and is roughly a blend of the HCCA and TVCN consensus guidance and 
deterministic GFS and ECMWF guidance.

The environmental conditions along the forecast track of Dora are 
generally conducive for maintenance of a very intense tropical 
cyclone during the next several days, with the exception of the mid- 
level dry air surrounding the system. Vertical wind shear will 
remain low during the next 4 days, while sea surface temperatures 
remain around 27C through around day 3. From day 3 onward, the SSTs 
increase into the 28/29C range, with vertical wind shear rising 
substantially by day 5. Although the satellite presentation of Dora 
has degraded slightly overnight, the continued annular appearance 
should prevent a rapid weakening of the system, and the official 
intensity forecast calls for a very slow and steady weakening trend 
during the next couple days. Beyond 48 hours, a slight increase in 
sea surface temperatures and ocean heat content may allow for some 
intensification of the tropical cyclone. As a result, the official 
intensity forecast has been increased slightly for days 3 and 4, 
with a rather sharp decrease in intensity shown by day 5 as 
increasing vertical wind shear should begin overwhelming Dora. This 
forecast is essentially a blend of the statistical and dynamical 
intensity guidance.


INIT  07/1500Z 12.4N 148.3W  115 KT 130 MPH
 12H  08/0000Z 12.2N 151.2W  110 KT 125 MPH
 24H  08/1200Z 12.0N 154.9W  105 KT 120 MPH
 36H  09/0000Z 12.0N 158.8W  100 KT 115 MPH
 48H  09/1200Z 12.2N 162.7W  100 KT 115 MPH
 60H  10/0000Z 12.6N 166.4W  100 KT 115 MPH
 72H  10/1200Z 13.1N 170.0W  100 KT 115 MPH
 96H  11/1200Z 15.0N 177.0W   90 KT 105 MPH
120H  12/1200Z 17.0N 177.0E   65 KT  75 MPH

Forecaster Jelsema

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