WPAC: DORA - Post-Tropical - Discussion

[cycloneye]

EP, 05, 2023080818, , BEST, 0, 115N, 1571W, 115, 953, HU

[Yellow Evan]

TXPN27 KNES 081750
TCSCNP

A. 05E (DORA)

B. 08/1730Z

C. 11.6N

D. 156.9W

E. ONE/GOES-W

F. T5.5/6.0

G. IR/EIR/VIS

H. REMARKS...OW EYE SURROUNDED BY B RING AND EMBEDDED IN LG YIELDS A
DT OF 5.5 AFTER ADDING 0.5 FOR EYE ADJUSTMENT. THE MET IS 5.0 BASED ON
A 24HR STEADY TREND. THE PT AGREES WITH THE DT. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...GATLING

[Sciencerocks]

[cycloneye]

Hurricane Dora Discussion Number 34
NWS Central Pacific Hurricane Center Honolulu HI EP052023
1100 AM HST Tue Aug 08 2023

Dora remains a powerful but small hurricane this morning, with a
persistent and relatively symmetric ring of deep convection
surrounding an eye that has recently become somewhat cloud-filled.
With a lack of discrete rain bands, a well-defined eye, and a
resistance to intensity change, Dora has displayed characteristics
of an annular hurricane for at least the last day or so, despite an
AHI (Annular Hurricane Index) score of zero this morning.
Regardless, utilizing subjective Dvorak current intensity estimates
of 6.0/115 kt, a 1618Z RCM-2 SAR pass, and 1431Z and 1436Z
microwave intensity estimates from UW-CIMSS' D-MINT, the initial
intensity is estimated to be 115 kt.

The initial motion vector for this advisory is 270/19 kt, as Dora
continues on its rapid westward track across the basin. A deep-layer
ridge moving westward in tandem with Dora had been supporting this
motion, and will generally continue to do so for the next day or
two. Despite the recent (somewhat unusual) south of west motion,
the forecast track anticipates that Dora will gradually gain
latitude as it reaches the southwestern periphery of the ridge. The
updated track forecast is nudged slightly northward from the
previous forecast, closer to the well-performing HAFS-A and TVCE
guidance. On the forecast track, Dora will pass well south of
Johnston Island Wednesday night, and into the western Pacific basin
on Friday.

Environmental conditions along the forecast track remain conducive
for maintaining a strong tropical cyclone over the next couple of
days, with relatively low vertical wind shear and sufficiently high
SSTs/OHC. Little change in intensity is indicated in the updated
forecast until the later forecast periods, when increasing
southwesterly vertical wind shear may lead to a fairly rapid demise
of the small cyclone's core. The updated intensity forecast lies
close to the IVCN consensus, with LGEM guidance influencing the
forecast in the later periods.


FORECAST POSITIONS AND MAX WINDS

INIT 08/2100Z 11.5N 158.1W 115 KT 130 MPH
12H 09/0600Z 11.6N 161.0W 110 KT 125 MPH
24H 09/1800Z 12.0N 164.8W 105 KT 120 MPH
36H 10/0600Z 12.5N 168.5W 100 KT 115 MPH
48H 10/1800Z 13.3N 172.0W 100 KT 115 MPH
60H 11/0600Z 14.3N 175.4W 95 KT 110 MPH
72H 11/1800Z 15.5N 178.5W 90 KT 105 MPH
96H 12/1800Z 17.6N 175.6E 65 KT 75 MPH
120H 13/1800Z 19.0N 170.0E 45 KT 50 MPH

$$
Forecaster Birchard

[Jr0d]

No recon.

I think the intensity is underestimated.

Just my opinion

[aspen]

No recon.

I think the intensity is underestimated.

Just my opinion

I wish we got recon. It’s not that far from Hawaii, even though it’s not a threat to land. Definitely underestimated by at least 5-10 kt at various points throughout its life.

The CDO is cooling again, and we almost have a perfect W ring. If the eye can warm up again then this has a shot at T7.0

[Sciencerocks]

[xtyphooncyclonex]

Dora has been a category four for at least 100 (nonconsecutive) hours now. Hector topped off at 96. This has to be a record or close to it, if not. Not even the supposedly bullish GFS called it.

It's also traveled >0.5 degrees south of even recent forecasts.

[Ntxw]

[cycloneye]

EP, 05, 2023080900, , BEST, 0, 114N, 1592W, 115, 953, HU

[Hurricane2022]

EP, 05, 2023080900, , BEST, 0, 114N, 1592W, 115, 953, HU

Central Pacific Hurricane Center.

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

[Yellow Evan]

CDO cooling but eye needs to clear cirrus aloft.

[Woofde]

Tis the traveling donut. Dora's living up to the name, seems like it's going to try to see each basin. Very pretty storm

[Teban54]

Tis the traveling donut. Dora's living up to the name, seems like it's going to try to see each basin. Very pretty storm

Don't forget... It started off as 95L in the Atlantic. It can even be argued that it may had been a brief TD back then.

[Fancy1002]

Is it just me or does she look like she’s ramping up again?

[Sciencerocks]

[cycloneye]

Hurricane Dora Discussion Number 35
NWS Central Pacific Hurricane Center Honolulu HI EP052023
500 PM HST Tue Aug 08 2023

Dora remains a powerful but small hurricane this afternoon, with a
persistent and relatively symmetric ring of deep convection
surrounding the eye. With a lack of discrete rain bands, a
well-defined eye, and a resistance to intensity change, Dora has
displayed characteristics of an annular hurricane. At fix time,
subjective Dvorak intensity estimate of 5.5 from both PHFO and SAB,
while objective Dvorak ADT shows a value of 5.8. Cold cloud tops
have wrapped around the convection this afternoon and little overall
change in appearance over the last 24 hours supports keeping the
intensity at 115 kt.

The initial motion vector for this advisory is 265/20 kt, as Dora
continues on its rapid westward track across the basin. A deep-layer
ridge moving westward in tandem with Dora had been supporting this
motion, and will generally continue to do so for the next day.
Despite the recent (somewhat unusual) south of west motion,
the forecast track anticipates that Dora will gradually gain
latitude as it reaches the southwestern periphery of the ridge. The
updated track forecast is nudged slightly southward from the
previous forecast, closer model consensus. On the forecast track,
Dora will pass well south of Johnston Island Wednesday night, and
into the western Pacific basin on Friday.

Environmental conditions along the forecast track remain conducive
for maintaining a strong tropical cyclone over the next couple of
days, with relatively low vertical wind shear and sufficiently high
SSTs/OHC. Little change in intensity is indicated in the updated
forecast until the later forecast periods, when increasing
southwesterly vertical wind shear may lead to a fairly rapid demise
of the small cyclone's core. The updated intensity forecast lies
close to the IVCN consensus, with LGEM guidance influencing the
forecast in the later periods.


FORECAST POSITIONS AND MAX WINDS

INIT 09/0300Z 11.4N 160.1W 115 KT 130 MPH
12H 09/1200Z 11.6N 163.1W 110 KT 125 MPH
24H 10/0000Z 12.0N 166.9W 105 KT 120 MPH
36H 10/1200Z 12.7N 170.5W 100 KT 115 MPH
48H 11/0000Z 13.5N 173.9W 95 KT 110 MPH
60H 11/1200Z 14.6N 177.1W 95 KT 110 MPH
72H 12/0000Z 15.8N 179.9E 90 KT 105 MPH
96H 13/0000Z 17.5N 174.0E 65 KT 75 MPH
120H 14/0000Z 18.9N 168.6E 45 KT 50 MPH

$$
Forecaster Foster/Birchard

[Sciencerocks]

 https://twitter.com/VortixWx/status/1689110405489082368

[Sciencerocks]

[cycloneye]

Hurricane Dora Discussion Number 36
NWS Central Pacific Hurricane Center Honolulu HI EP052023
1100 PM HST Tue Aug 08 2023

Dora continues to be a compact and powerful hurricane on a rapid
westward track across the central Pacific. The system continues to
exhibit annular characteristics on satellite with its
compact size, well-defined eye, and its persistent and symmetric
ring of deep convection. The eye at times has appeared to become a
little cloud filled, but then quickly clears out again. The latest
subjective Dvorak estimates from JTWC and PHFO were 6.0 and SAB was
5.5. Objective estimates from CIMSS are between 110 and 115 kt.
The initial intensity has been held at 115 kt with this
advisory.

The initial motion intensity for this advisory is 270/20 kt. Model
guidance remains tightly clustered through the remaining time Dora
will be in the central Pacific basin, with more variability noted as
the system exits the central Pacific around hour 60. The forecast
track remains closely aligned with the previous advisory and follows
closely the TVCN model consensus. This maintains a westward track
for another day, and then turns to the west-northwest as it begins
to round the southwest edge of the ridge to the north. On this
track, the system will pass far south of Johnston Island Wednesday
night. The system then turns to the northwest as it moves into the
western Pacific basin Friday.

The intensity forecast continues to be the more challenging aspect
of Dora's future. The environmental conditions remain conducive for
Dora to remain a strong tropical cyclone over the next couple of
days, with little vertical wind shear and sufficiently warm
SSTs/OHC. There is good agreement that Dora will be moving over
slightly warmer waters and increased ocean heat content in about 24
hours as the cyclone starts to move to the west-northwest. While
these warmer waters could contribute to maintaining, or even
strengthening of the cyclone, southwesterly deep layer shear is
expected to begin to increase shortly thereafter, as Dora rounds the
ridge to the north. The shear is expected to increase as Dora
approaches the date line Friday. The latest ECMWF SHIPS guidance
maintains the 115 kt intensity for the next 36 hours while other
guidance slowly weakens the system. With little change expected with
Dora's immediate environment for the next day, and the ECMWF holding
it higher, have held the intensity a touch higher than the previous
forecast for the first 48 hours. The forecast then follows the
weakening in the guidance as was reflected in the previous advisory.
This update to the intensity places it on the high end of the model
consensus in the short term, and leans towards the LGEM guidance for
the later periods.


FORECAST POSITIONS AND MAX WINDS

INIT 09/0900Z 11.4N 162.1W 115 KT 130 MPH
12H 09/1800Z 11.7N 165.0W 110 KT 125 MPH
24H 10/0600Z 12.3N 168.8W 110 KT 125 MPH
36H 10/1800Z 13.1N 172.5W 105 KT 120 MPH
48H 11/0600Z 14.1N 175.9W 100 KT 115 MPH
60H 11/1800Z 15.2N 179.0W 95 KT 110 MPH
72H 12/0600Z 16.3N 178.0E 90 KT 105 MPH
96H 13/0600Z 17.8N 172.3E 65 KT 75 MPH
120H 14/0600Z 19.2N 167.3E 45 KT 50 MPH

$$
Forecaster M Ballard/Jelsema