WPAC: HONE - Post-Tropical - Discussion

[cycloneye]

Tropical Storm Hone Discussion Number 38
NWS Central Pacific Hurricane Center Honolulu HI CP012024
1100 AM HST Sat Aug 31 2024

In a seemingly never-ending cycle, Hone has been getting a very
vigorous burst of sheared convection over the low level circulation
center each of the last several nights, only to have the center
become fully exposed each morning. Today is no exception, and deep
convection has been mainly limited to Hone's outer bands. The CIRA
ProxyVis has been particularly helpful to monitor this daily
evolution. It should be noted that the low level circulation center
looks a bit more ragged this morning than it has in recent days.
Current intensity has been maintained at 35 kt, splitting the
difference between the somewhat lower subjective Dvorak estimates
and the slightly stronger objective machine estimates, and also with
a nod to the overnight ASCAT passes.

The broad circulation of a low aloft about 200 nm south of Midway
Atoll is beginning to pull Hone's low level circulation northward,
and after about 24 hours of erratic, wobbly westward motion, the
initial motion for this advisory is now 345/6. Track guidance
remains in remarkably good agreement that Hone will continue to get
pulled toward the center of the low aloft, with the circulations
becoming vertically stacked in about 36 to 48 hours. A slower and
perhaps erratic west-northwest motion is expected as that occurs.
Although not explicitly shown in our forecast, both the
deterministic GFS and ECMWF execute a complete loop of Hone over
the International Date Line Sunday and Sunday night (HST).
Afterwards, Hone should resume a more northward motion into
the North Pacific. Beyond about 48 hours, this forecast track shifts
a little to the right and slower than the previous forecast, to
be more in line with TVCN and other consensus guidance.

It remains somewhat questionable whether the low level circulation
center of Hone will survive the alignment with the low aloft.
However, guidance continues to show that it should do so, and
conditions do generally appear to be favorable for restrengthening.
Shear decreases to less than 10 kt within 24 hours, and Hone
encounters the warmest sea surface temperatures yet along its
track, near 29C. Our forecast has Hone continuing to peak in
intensity in 2 to 3 days, similar to IVCN. Afterward, Hone should
begin to gradually weaken as sea surface temperatures along the
track begin to cool, and mid-level dry air becomes entrained into
the cyclone.

FORECAST POSITIONS AND MAX WINDS

INIT 31/2100Z 22.7N 176.3W 35 KT 40 MPH
12H 01/0600Z 23.7N 176.7W 40 KT 45 MPH
24H 01/1800Z 25.2N 177.9W 40 KT 45 MPH
36H 02/0600Z 25.9N 179.6W 40 KT 45 MPH
48H 02/1800Z 26.8N 179.9E 45 KT 50 MPH
60H 03/0600Z 28.5N 179.7E 50 KT 60 MPH
72H 03/1800Z 30.0N 179.4E 50 KT 60 MPH
96H 04/1800Z 32.1N 177.8E 45 KT 50 MPH
120H 05/1800Z 33.8N 176.5E 40 KT 45 MPH

$$
Forecaster R Ballard

[MarioProtVI]

That new burst might’ve just nuked the fragile LLC looking at satellite.. either that or it’s reforming (don’t see any indication as to where).

[Hayabusa]

JMA now issuing gale warning forecast about Hone implicitly on their 06Z surface map analysis

WWJP27 RJTD 010600
WARNING AND SUMMARY 010600.
WARNING VALID 020600.
WARNING IS UPDATED EVERY 6 HOURS.
GALE WARNING.
EXPECTED NORTHERLY TO NORTHEASTERLY WINDS 30 TO 35 KNOTS WITHIN NEXT
24 HOURS
PREVAILING OVER WATERS BOUNDED BY 29N 177E 29N 180E 26N 180E 26N 177E
29N 177E.
GALE WARNING.
EXPECTED NORTHERLY TO NORTHWESTERLY WINDS 30 TO 35 KNOTS WITHIN NEXT
24 HOURS
PREVAILING OVER WATERS BOUNDED BY 26N 177E 26N 180E 23N 180E 23N 177E
26N 177E.

[Teban54]

Welp. So much for Typhoon Hone...

[cycloneye]

Post-Tropical Cyclone Hone Discussion Number 42
NWS Central Pacific Hurricane Center Honolulu HI CP012024
1100 AM HST Sun Sep 01 2024

Hone is now classified as a post-tropical cyclone, so this is the
final advisory. Geostationary satellite imagery reveals that the
low-level circulation center of Hone has become indistinguishable
this morning as it was absorbed into large band of convection
surrounding a deep cutoff low. The center of this merged system,
which now reflects the location of the dominant extratropical cutoff
low, jumped westward considerably as the circulation of Hone was
absorbed. An ASCAT pass from yesterday evening showed a broad area
of gale force winds within a large convective band, and this was
incorporated into this final forecast for the merged extratropical
low.

The post-tropical low of former Hone will continue to move westward
and lose forward motion over the next 12 hours, eventually stalling
tonight as it becomes aligned with the upper-level low. The deep
low will then drift northward near the International Date Line on
days 2 through 4 and likely dissipate by day 5. The post-tropical
low is expected to maintain gale force winds in the northern
semicircle for the next couple of days. If convection does reform
over the center, there is a chance that post-tropical Hone could
regain tropical characteristics over the next 2 days or so. The
Central Pacific Hurricane Center will closely monitor for
redevelopment and the need to resume bulletins east of the
International Date Line.

Since Hone is now a post-tropical low and this is the final
advisory from the Central Pacific Hurricane Center, the Tropical
Storm Watch for Kure and Midway Atolls has been discontinued.
However, these atolls could experience gale force winds during the
next couple of days. Additional information can be found in High
Seas forecasts issued by the National Weather Service in Honolulu,
Hawaii under AWIPS header HFOHSFNP and WMO header FZPN20 PHFO. If
this system redevelops west of the International Date Line,
bulletins would be issued by RSMC Tokyo, Japan.


FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 26.3N 179.3E 35 KT 40 MPH...POST-TROPICAL
12H 02/0600Z 26.6N 178.8E 35 KT 40 MPH...POST-TROPICAL
24H 02/1800Z 27.1N 178.5E 35 KT 40 MPH...POST-TROPICAL
36H 03/0600Z 28.5N 179.2E 35 KT 40 MPH...POST-TROPICAL
48H 03/1800Z 29.8N 179.9E 30 KT 35 MPH...POST-TROPICAL
60H 04/0600Z 31.1N 179.0E 25 KT 30 MPH...POST-TROPICAL
72H 04/1800Z 32.1N 177.8E 25 KT 30 MPH...POST-TROPICAL
96H 05/1800Z 33.2N 176.1E 20 KT 25 MPH...DISSIPATED

$$
Forecaster Wroe

[Subtrop]

(1) AN AREA OF CONVECTION (INVEST 01C) HAS PERSISTED NEAR 26.1N
179.5E, APPROXIMATELY 206 NM SOUTHWEST OF MIDWAY. THIS SYSTEM IS
CLASSIFIED AS A SUBTROPICAL DEPRESSION, GENERALLY CHARACTERIZED AS
HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY AND A 012130Z ASCAT METOP-C 25KM
IMAGE DEPICTS A WEAK ASYMMETRIC SYSTEM WITH A LARGE RADIUS OF MAX
WINDS. ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY UNFAVORABLE CONDITIONS
FOR TROPICAL TRANSITION WITH HIGH (27-28 C) SEA SURFACE TEMPERATURES
AND LOW TO MODERATE (15 -20 KTS) VERTICAL WINDSHEAR, OFFSET BY
SIGNIFICANT DRY AIR ENTRAINMENT AND CONVERGENCE ALOFT. GLOBAL MODELS
ARE IN AGREEMENT OF A TRACK NORTHWARD FOLLOWED BY A QUICK DISSIPATION
OF THE SYSTEM. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO
25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS LOW.