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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.
FORECAST POSITIONS AND MAX WINDS
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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