EPAC: KIKO - Hurricane - Discussion

[cycloneye]

Hurricane Kiko Discussion Number 23
NWS National Hurricane Center Miami FL EP112025
Issued by the NWS Weather Prediction Center College Park MD
1100 AM HST Fri Sep 05 2025

The satellite presentation of Kiko has shown significant improvement
since the last advisory, with the eye clearing out and its coldest
cloud tops more fully encircling it. The most recent subjective
Dvorak current intensity estimates from TAFB and SAB were T6.0/115
kt and T5.5/102 kt. Objective estimates from UW-CIMSS have been
increasing, with the latest ADT estimate up to to 115 knots.
Considering the continuing improvement since the time of the 1800
UTC fixes, the intensity has been set at 115 kts, which could be
conservative as the eye continues to clear out.

Kiko continues to move to the west-northwest, or 290 degrees, at 9
kt. The western extent of a subtropical ridge to the north of the
cyclone is eroding due to a developing upper-level low north of
Hawaii. This general west-northwestward motion along with a gradual
increase in forward speed is forecast into early next week, as Kiko
moves along the southwest periphery of this subtropical ridge and
towards the upper-level low to the north and northwest of the
Hawaiian Islands. The track forecast has shifted northward due to
the slightly more northward initial motion, and poleward shift in
the track guidance. Based on the forecast track Kiko is expected to
cross 140W into the central Pacific Ocean overnight into Saturday
morning. The track forecast remains close to the HCCA consensus
aid. By the end of the forecast track, Kiko may turn more westward
as it becomes increasingly steered by the low-level flow.

The hurricane will remain over warm waters of 27–28C for the next 12
hours, while influenced by light northeasterly vertical wind shear
embedded in a drier than normal mid-level environment. These
environmental factors should keep Kiko a smaller than average sized
storm as the dry air prevents more prominent outer rain bands from
forming. Conditions still appear favorable for additional
intensification, so the latest intensity and given the current
improving structure, more intensification is shown than before, well
above all of the available guidance. This forecast also fits in
with the possibility for Kiko developing annular structure which
could keep it stronger than the forecast intensity guidance.
Thereafter, Kiko will move over cooler waters and an even drier
mid-level environment. After 48 hours, west-southwesterly vertical
wind shear increases steadily, exceeding 30 kt by Wednesday. This
shear may help import the nearby environmental dry air into Kiko's
small core. Thus, rapid weakening of the tropical cyclone is
forecast as Kiko passes to the northeast of the Hawaiian Islands by
the end of the forecast. After the initial bump in short-term
intensity, this forecast trends back to the middle of the consensus
envelope early next week, and then trends lower by the end of the
forecast period.

Key Messages:

1. Kiko is forecast to approach the Hawaiian Islands during the
early to the middle portion of next week. Impacts from rain and wind
remain a possibility, but it is too soon to determine the exact
location or magnitude of these impacts, and interests there should
continue to monitor the progress of this storm.


FORECAST POSITIONS AND MAX WINDS

INIT 05/2100Z 14.5N 137.8W 115 KT 130 MPH
12H 06/0600Z 14.9N 139.1W 125 KT 145 MPH
24H 06/1800Z 15.6N 141.0W 120 KT 140 MPH
36H 07/0600Z 16.3N 143.0W 115 KT 130 MPH
48H 07/1800Z 17.2N 145.0W 100 KT 115 MPH
60H 08/0600Z 18.2N 147.0W 90 KT 105 MPH
72H 08/1800Z 19.4N 149.1W 75 KT 85 MPH
96H 09/1800Z 21.7N 153.5W 50 KT 60 MPH
120H 10/1800Z 23.7N 158.2W 35 KT 40 MPH

$$
Forecaster Roth/Papin

[Kingarabian]

So Kiko manages to become annular after all. Should extend its time as a major somewhat. The basin needs more ACE to catch up with the climatological average especially since there is no storm waiting to form at the moment.

Still isn't annular by any means. Massive feeder band to its south/south west. It may attempt to transition into one tomorrow.

[aspen]

Looked away for a few hours and suddenly Kiko is RI’ing again. Best it’s looked so far. Probably 125 kt or so now, but it’s yet another one of those EPac Cat 4s with a B to mostly W ring that Dvorak does really poorly with (Douglas, Darby, Dora, Gilma), so it may not go over 120 kt operationally.

[Ntxw]

She's going poleward and warm, circular eye now.

[Teban54]

An impressive comeback.

[Kingarabian]

Booking it WNW. Heading almost looks NW at this point.

[cycloneye]

EP, 11, 2025090600, , BEST, 0, 147N, 1382W, 115, 951, HU

[cycloneye]

BULLETIN
Hurricane Kiko Advisory Number 24
NWS National Hurricane Center Miami FL EP112025
500 PM HST Fri Sep 05 2025

...KIKO STRENGTHENS AS A CATEGORY FOUR HURRICANE AS IT APPROACHES
THE CENTRAL PACIFIC BASIN...


SUMMARY OF 500 PM HST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...14.9N 138.7W
ABOUT 1130 MI...1820 KM ESE OF HILO HAWAII
ABOUT 1335 MI...2145 KM ESE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...140 MPH...220 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...946 MB...27.94 INCHES



Hurricane Kiko Discussion Number 24
NWS National Hurricane Center Miami FL EP112025
500 PM HST Fri Sep 05 2025

Kiko has continued to intensify this afternoon and remains a
category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. The
eye is now surrounded by a large ring of very cold cloud tops, and
the cyclone has taken on a structure more typical of annular
hurricanes. A GMI microwave pass from 2224 UTC confirmed a symmetric
inner-core with a complete ring of deep convection around the eye.
The latest objective estimates from UW-CIMSS are as high as 122 kt.
Subjective Dvorak classifications from SAB and TAFB are both
T6.0/115 kt. Blending the higher objective estimates with the
slightly lower subjective classifications yields an initial
intensity of 120 kt.

Kiko is moving west-northwestward, or 290 degrees at 10 kt. The
cyclone remains steered along the southwestern flank of a
subtropical ridge, while an upper-level low north of Hawaii is
helping to erode the western periphery of the ridge. This general
motion with some increase in forward speed should persist through
the weekend, with Kiko expected to cross into the central Pacific
basin late tonight or early Saturday. The official forecast track is
near the HCCA consensus and essentially unchanged from the previous
advisory. However, a track slightly to the left of the official
forecast would bring Kiko closer to the Big Island. Historically,
cyclones approaching the Big Island from the east can slow and
deflect northward as the island terrain disrupts the low-level flow
and alters the steering currents.

Kiko should remain a powerful hurricane for the next 12–24 hours
while traversing 26–27 C waters with light north-northeasterly
shear. Its annular structure may allow it to resist weakening longer
than typical guidance, despite the surrounding dry environment in
the mid- to upper levels. Beyond 48 hours, a combination of cooler
waters, dry mid-level air, and strengthening west-southwesterly
shear exceeding 30 kt will likely induce rapid weakening. The
official intensity forecast holds Kiko above most of the available
guidance into the weekend, then trends more toward the consensus
aids later in the weekend and early next week.


Key Messages:

1. Kiko is forecast to approach the Hawaiian Islands during the
early to the middle portion of next week. Impacts from rain and wind
remain a possibility, but it is too soon to determine the exact
location or magnitude of these impacts, and interests there should
continue to monitor the progress of this storm.

2. Swells generated by Kiko are expected to begin reaching the Big
Island and Maui by Sunday. These swells will gradually build and are
forecast to peak along east facing exposures of the Hawaiian Islands
late Monday through midweek, potentially producing life-threatening
surf and rip currents. Listen for later advisories and possible
warnings from the National Weather Service.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0300Z 14.9N 138.7W 120 KT 140 MPH
12H 06/1200Z 15.4N 140.1W 125 KT 145 MPH
24H 07/0000Z 16.1N 142.0W 120 KT 140 MPH
36H 07/1200Z 16.9N 143.9W 115 KT 130 MPH
48H 08/0000Z 17.8N 145.9W 100 KT 115 MPH
60H 08/1200Z 19.0N 148.0W 90 KT 105 MPH
72H 09/0000Z 20.2N 150.2W 75 KT 85 MPH
96H 10/0000Z 22.4N 154.8W 50 KT 60 MPH
120H 11/0000Z 24.3N 159.8W 35 KT 40 MPH

$$
Forecaster Gibbs (CPHC)

[Kingarabian]

Looks like the transition to annular is beginning.

[Yellow Evan]

After completing an ERC, Kiko has pulled off another round of intensification. Likely stronger than the T6.0 explicitly analyzed.

[Yellow Evan]

I'd peg peak intensity about here at around 125 knots.

Another ERC is pending, though this will probably be peak.

[Yellow Evan]

Track guidance has shifted north today in response to a stronger upper low. This also naturally means more wind shear, even if said upper trough/low aids poleward outflow initially. Threat to Hawaii has decreased.

[Sciencerocks]

[cycloneye]

Hurricane Kiko Discussion Number 25
NWS National Hurricane Center Miami FL EP112025
1100 PM HST Fri Sep 05 2025

Kiko has held steady this evening with only minor fluctuations in
intensity, maintaining its Category 4 strength on the Saffir-Simpson
Hurricane Wind Scale. The eye remains well-defined and is mostly
surrounded by a sufficiently large light gray shade on the Dvorak BD
curve, with occasional hints of an even stronger pattern when a
nearly sufficiently large black shade surrounds the eye. The
latest subjective Dvorak current intensities varied, with TAFB at
6.5/127 kt, and SAB and HFO both at 6.0/115 kt. Objective estimates
from UW-CIMSS ranged between 115 and 122 kt. Blending the subjective
and objective data supports holding the initial intensity at 120 kt
for this advisory.

Kiko continues to move west-northwestward, or 285 degrees at 9 kt,
and will enter the Central Pacific basin within a few hours. The
cyclone remains steered by the southwestern flank of a subtropical
ridge, while an upper-level low north of Hawaii continues to
gradually erode the ridge’s western periphery. This general motion
is expected to persist through the weekend. By early to mid next
week (days 3 to 5), it is expected to turn slightly more westward
under increasing influence from the low-level steering flow, keeping
the center north of the main Hawaiian Islands. The latest forecast
track lies slightly to the right of the previous NHC forecast and
represents a blend between that solution and the consensus aids.

Kiko is expected to maintain its major hurricane intensity through
Saturday while traversing waters near 26 C and under minimal shear.
Its annular structure should allow the system to resist weakening
longer than typically observed, even as it begins to move over
cooler waters. By late this weekend, Kiko will encounter
progressively cooler waters and steadily increasing
west-southwesterly shear, which should induce weakening at a more
rapid rate as it begins to approach the Hawaiian Islands. The
official intensity forecast holds Kiko above much of the guidance
through the first half of the weekend, before trending closer to the
consensus aids late in the weekend and early next week.

Key Messages:

1. Kiko is forecast to approach the Hawaiian Islands during the
early to the middle portion of next week. Impacts from rain and wind
remain a possibility, but it is too soon to determine the exact
location or magnitude of these impacts, and interests there should
continue to monitor the progress of this storm.

2. Swells generated by Kiko are expected to begin reaching the Big
Island and Maui by Sunday. These swells will gradually build and are
forecast to peak along east facing exposures of the Hawaiian Islands
late Monday through midweek, potentially producing life-threatening
surf and rip currents. Listen for later advisories and possible
warnings from the National Weather Service.

Future information on Kiko can be found under Central Pacific basin
headers beginning at 500 AM HST. Future Tropical Cyclone Discussions
will be issued under AWIPS header HFOTCDCP4 and WMO header WTPA44
PHFO. Products will continue to be available on the web at
hurricanes.gov.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0900Z 15.1N 139.7W 120 KT 140 MPH
12H 06/1800Z 15.7N 141.0W 120 KT 140 MPH
24H 07/0600Z 16.5N 142.9W 115 KT 130 MPH
36H 07/1800Z 17.4N 144.9W 110 KT 125 MPH
48H 08/0600Z 18.5N 146.9W 100 KT 115 MPH
60H 08/1800Z 19.6N 149.0W 90 KT 105 MPH
72H 09/0600Z 21.0N 151.2W 75 KT 85 MPH
96H 10/0600Z 23.1N 155.9W 50 KT 60 MPH
120H 11/0600Z 24.9N 160.9W 35 KT 40 MPH

$$
Forecaster Gibbs (CPHC)

[cycloneye]

Hurricane Kiko Discussion Number 26
NWS Central Pacific Hurricane Center Honolulu HI EP112025
Issued by NWS National Hurricane Center Miami FL
500 AM HST Sat Sep 06 2025

Kiko is maintaining a well-defined eye on satellite imagery, but
the convection is becoming eroded over the northern semicircle
of the system. Also, the cloud tops have warmed somewhat since
last night. The advisory intensity is set at 115 kt, in general
agreement with Dvorak Current Intensity estimates from SAB and TAFB
and close to the objective estimates from UW/CIMSS. Scatterometer
data overnight showed that the system remains rather small, with
tropical-storm force winds over a diameter of 100 n mi or less.

The hurricane continues on its west-northwestward trek with an
initial motion estimate of 290/10 kt. Kiko is moving on the
southwestern side of a mid-level ridge. A mid- to upper-level
trough near Hawaii is eroding the ridge's western periphery, so a
a nearly northwestward motion is likely around 72 hours. Later in
the forecast period, a more westward track is likely as the
weakening cyclone becomes more responsive to the lower-level
steering flow. The official forecast track is just slightly north
of the previous official prediction, with some of the consensus
track prediction aids even farther north of the latest official
track. This would keep the center of Kiko north of the main
Hawaiian Islands. However there is still some uncertainty in
forecasts at 3 days and beyond.

Kiko is traversing SSTs near 26 deg C and should continue to pass
over marginally warm ocean waters during the next few days.
However, the trough near Hawaii is likely to impart increasingly
strong south-southwesterly vertical wind shear over the cyclone for
the next several days. The official intensity forecast shows
gradual weakening, and is generally above the consensus model
guidance. Simulated satellite imagery from the global models shows
the deep convection becoming disorganized while the system passes
near the Hawaiian Islands, so the official intensity forecast at
3-5 days could be generous.

An Air Force Hurricane Hunter aircraft is scheduled to investigate
Kiko later today to provide a better look at Kiko's intensity and
structure.

Key Messages:

1. Kiko is forecast to approach the Hawaiian Islands during the
early to middle portion of next week. Impacts from rain and wind
are possible over portions of the Islands, but it is still too soon
to determine the exact location or magnitude of these potential
impacts, and interests there should continue to monitor the progress
of this storm.

2. Swells generated by Kiko are expected to begin reaching the Big
Island and Maui by Sunday. These swells will gradually build and are
forecast to peak along east-facing exposures of the Hawaiian
Islands late Monday through midweek, potentially producing
life-threatening surf and rip currents. Listen for later advisories
and possible warnings from the National Weather Service.


FORECAST POSITIONS AND MAX WINDS

INIT 06/1500Z 15.5N 140.5W 115 KT 130 MPH
12H 07/0000Z 16.1N 142.0W 110 KT 125 MPH
24H 07/1200Z 17.0N 143.9W 105 KT 120 MPH
36H 08/0000Z 18.0N 145.9W 100 KT 115 MPH
48H 08/1200Z 19.1N 147.9W 90 KT 105 MPH
60H 09/0000Z 20.4N 150.0W 80 KT 90 MPH
72H 09/1200Z 21.8N 152.2W 65 KT 75 MPH
96H 10/1200Z 24.1N 157.0W 45 KT 50 MPH
120H 11/1200Z 25.5N 162.0W 35 KT 40 MPH

$$
Forecaster Pasch

[cycloneye]

Annular?

[Kingarabian]

Annular?

https://i.imgur.com/YQ9q6pd.gif

3/4 of the way there. Still looks impressive.

[Kingarabian]

Looks wise it's not annular. There's still traditional banding on visible/IR/MW. Weird considering the dry air etc. But characteristics wise, it is.

[Hurricane2022]

 https://x.com/CIRA_CSU/status/1964154355495686206

[Kingarabian]