东太平洋热带风暴“奥克塔夫”(15E.Octave)

ygsj24

000
WTPZ45 KNHC 022039
TCDEP5

Tropical Storm Octave Discussion Number  11
NWS National Hurricane Center Miami FL       EP152025
200 PM PDT Thu Oct 02 2025

Octave continues to be disrupted by strong easterly vertical wind
shear.  There is a rather sharp edge of the cloud shield on the
eastern side of the upper-level cloud pattern and the low-level
center remains near this eastern edge.  Convective banding features
are not very well defined and the upper-tropospheric outflow
continues to be inhibited to the east of the system.  The advisory
intensity has been adjusted to 50 kt based on a recent ASCAT
overpass and the 34-kt wind radii have also been adjusted slightly
based on the scatterometer data.

Center fixes indicate that the motion remains west-northwestward,
or 285/7 kt.  The tropical cyclone continues to move along the
southern side of a weak mid-level subtropical ridge, and should
continue to do so for the next couple of days.  By 72 hours or so,
Octave should turn northward and slow down as it encounters a
weakness in the ridge.  Later in the forecast period, the system is
expected to turn eastward as it begins to become drawn into a larger
developing tropical cyclone off the southwest coast of Mexico.  The
official forecast track is similar to the previous one also similar
to the multi-model consensus prediction.

Dynamical models indicate that the vertical wind shear over Octave
is not expected to decrease significantly for the next couple of
days.  Later in the forecast period, the shear is likely to lessen
although the air mass is expected to become somewhat drier by that
time and the developing tropical cyclone to the east of Octave could
also have a negative influence.  The official forecast calls for
some re-strengthening around day 3, however it is above most of the
model guidance.  This should be considered a low-confidence
forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 12.7N 119.0W   50 KT  60 MPH
12H  03/0600Z 13.0N 119.9W   50 KT  60 MPH
24H  03/1800Z 13.5N 121.1W   50 KT  60 MPH
36H  04/0600Z 14.0N 122.3W   50 KT  60 MPH
48H  04/1800Z 14.6N 123.4W   50 KT  60 MPH
60H  05/0600Z 15.0N 123.9W   55 KT  65 MPH
72H  05/1800Z 15.3N 123.7W   60 KT  70 MPH
96H  06/1800Z 15.5N 123.5W   60 KT  70 MPH
120H  07/1800Z 15.7N 120.5W   45 KT  50 MPH

$$
Forecaster Pasch

pocketbox

全球热带气旋监测公报
预报：张怡驰、张增海  签发：黄奕武  2025 年 10 月 03 日 10 时
“奥克塔夫”向西偏北方向移动

时        间:   3日08时（北京时，下同）

海        域:    东北太平洋

命        名:    “奥克塔夫”，OCTAVE

中心位置:    北纬12.8度，西经119.3度

强度等级:    热带风暴

最大风力:    10级，25米/秒，相当于我国的强热带风暴级

中心气压:    997百帕

参考位置:    距离墨西哥南下加利福尼亚州圣卢卡斯角西南方向约1470公里

变化过程:    过去24小时，“奥克塔夫”强度维持10级

预报结论:   “奥克塔夫”将以每小时12公里左右的速度向西偏北方向移动，强度维持



图1 卫星红外监测图像（北京时间2025年10月3日08时00分）

ygsj24

000
WTPZ45 KNHC 030247
TCDEP5

Tropical Storm Octave Discussion Number  12
NWS National Hurricane Center Miami FL       EP152025
800 PM PDT Thu Oct 02 2025

Octave appears to be in a delicate state this evening.  Hints of the
low-level circulation appeared on the last-light GOES visible
imagery while the afternoon's decaying convection drifted westward.
However, a new burst of deep convection has developed just to the
west of the center.  Objective and subjective satellite intensity
estimates have remained rather steady.  Therefore, the initial
intensity remains at 50 kt, representing a blend of the TAFB and SAB
Dvorak estimates.

The cyclone is moving steadily west-northwestward at 6 kt along the
southern side of a weak subtropical ridge.  The ridge should
continue to steer Octave in this direction for the next couple of
days.  By day 3, the storm should slowly drift northward followed by
a sharp turn to the east as it moves in the wake of a stronger
tropical cyclone (Invest 99) off the coast of southwestern Mexico.  
The official forecast track is similar to the previous one, and is
also similar to the multi-model consensus prediction.

Both the GFS and ECMWF indicate that the atmospheric conditions
could become a little more conducive in about a day and a half.  If
Octave can maintain its current state, vertical wind shear is
expected to abate Friday night or Saturday morning.  The latest NHC
intensity forecast calls for gradual strengthening between 48 to 72
h, followed by steady weakening as the vertical wind shear is
expected to increase once again.  The near-term prediction lies on
the high end of the guidance envelope and blends closer to the
corrected consensus aid, HCCA, by the mid-to-latter portion of the
forecast period.


FORECAST POSITIONS AND MAX WINDS

INIT  03/0300Z 12.9N 119.6W   50 KT  60 MPH
12H  03/1200Z 13.2N 120.5W   50 KT  60 MPH
24H  04/0000Z 13.8N 121.8W   50 KT  60 MPH
36H  04/1200Z 14.4N 122.9W   50 KT  60 MPH
48H  05/0000Z 14.8N 123.6W   55 KT  65 MPH
60H  05/1200Z 15.2N 123.8W   60 KT  70 MPH
72H  06/0000Z 15.5N 123.3W   60 KT  70 MPH
96H  07/0000Z 15.7N 121.3W   50 KT  60 MPH
120H  08/0000Z 15.4N 118.7W   40 KT  45 MPH

$$
Forecaster Bucci

ygsj24

000
WTPZ45 KNHC 030841
TCDEP5

Tropical Storm Octave Discussion Number  13
NWS National Hurricane Center Miami FL       EP152025
200 AM PDT Fri Oct 03 2025

Octave remains a sheared tropical cyclone, with the low-level center
mostly exposed and displaced east of a recent burst of deep
convection. The latest subjective Dvorak current intensity estimates
from TAFB and SAB are 3.5/55 kt and 3.0/45 kt, respectively, while
the UW-CIMSS objective estimates have ranged between 35 and 44 kt
during the past several hours. A recent 03/0435Z Metop-B ASCAT pass
was helpful in determining the tropical-storm-force wind radii and
the center location, and it also indicated peak winds of 38 kt.
Based on a blend of these data, and accounting for some
undersampling in the scatterometer data, the initial intensity is
set at 45 kt for this advisory.

Octave is estimated to be moving west-northwestward, or 290 degrees
at 7 kt.  This general motion is expected to continue through
tonight as the cyclone is steered along the southern periphery of a
weak subtropical ridge located to its north.  Octave is forecast to
slow considerably and turn northward by late Saturday, followed by a
sharp eastward turn by late Sunday as a mid-level trough approaches
from the northwest and the subtropical ridge to its east weakens due
to the influence of a larger tropical cyclone developing offshore of
the southwestern or west-central coast of Mexico.  The new NHC track
forecast is similar to the previous prediction and lies near a blend
of the multi-model consensus aids.

Octave will remain over warm waters and within a moist environment
for the next few days.  East-southeasterly vertical wind shear is
expected to continue impacting the cyclone for the next 12 to 24
hours, which should inhibit strengthening.  Beyond 24 hours, the
shear is forecast to decrease to light levels, while the cyclone
remains over waters near 27C and within a sufficiently moist
environment.  These conditions should allow for some modest
strengthening over the weekend.  By days 4 and 5, Octave is forecast
to encounter increasing southeasterly shear and a drier mid-level
environment, which should result in steady weakening.  The official
intensity forecast has been lowered slightly to account for a
notable decrease among the various intensity aids.  The forecast now
lies above most of the intensity guidance throughout the period, and
future forecasts may need to adjust the intensity downward further
if the weakening trends in the guidance persist.


FORECAST POSITIONS AND MAX WINDS

INIT  03/0900Z 13.1N 120.4W   45 KT  50 MPH
12H  03/1800Z 13.6N 121.3W   45 KT  50 MPH
24H  04/0600Z 14.1N 122.6W   45 KT  50 MPH
36H  04/1800Z 14.6N 123.6W   50 KT  60 MPH
48H  05/0600Z 15.1N 124.0W   55 KT  65 MPH
60H  05/1800Z 15.5N 123.9W   55 KT  65 MPH
72H  06/0600Z 15.5N 123.3W   50 KT  60 MPH
96H  07/0600Z 15.4N 121.8W   40 KT  45 MPH
120H  08/0600Z 15.1N 119.4W   35 KT  40 MPH

$$
Forecaster Jelsema (CPHC)

pocketbox

全球热带气旋监测公报
预报：张怡驰、张增海  签发：黄奕武  2025 年 10 月 03 日 18 时
“奥克塔夫”向西偏北方向移动

时        间:   3日14时（北京时，下同）

海        域:    东北太平洋

命        名:    “奥克塔夫”，OCTAVE

中心位置:    北纬13.1度，西经120.0度

强度等级:    热带风暴

最大风力:    9级，23米/秒，相当于我国的热带风暴级

中心气压:    998百帕

参考位置:    距离墨西哥南下加利福尼亚州圣卢卡斯角西南方向约1521公里

变化过程:    过去24小时，“奥克塔夫”强度由10级减弱至9级

预报结论:   “奥克塔夫”将以每小时11公里左右的速度向西偏北方向移动，强度先小幅度减弱后维持



图1 卫星红外监测图像（北京时间2025年10月3日14时00分）

pocketbox

WTPZ45 KNHC 031433
TCDEP5

Tropical Storm Octave Discussion Number  14
NWS National Hurricane Center Miami FL       EP152025
800 AM PDT Fri Oct 03 2025

Octave has changed little during the past several hours. The system
still appears to be sheared, and satellite intensity estimates are
similar to six hours ago, so the intensity is held at 45 kt for this
advisory. The outlook for Octave is relatively high confidence for
the next day or so. Octave should continue moving west-northwestward
near 7 kt, steered by a small mid-level ridge centered between
Octave and the Baja California Peninsula. During that time, it
should also remain somewhat sheared with its intensity only
fluctuating slightly up or down over that period. Confidence in the
NHC forecast is high through Saturday.

However, by Saturday evening, the uncertainty in the forecast grows
substantially. First, the aforementioned ridge is expected to
weaken, resulting in very weak steering flow for the following
couple of days. A trough over the far northern east Pacific will
probably cause Octave to turn and drift eastward during that time.
After that, another larger disturbance to Octave's east will likely
also influence Octave's track, potentially causing it to move faster
toward the east by the middle of next week. With steering currents
weak, only small changes in the environment could have a large
impact on Octave's track. The spread in the track guidance grows
substantially beyond 48 h, so confidence in the forecast is much
lower at that point.

The intensity is likewise uncertain beyond 24 to 36 h.  The shear
affecting Octave is expected to lessen, and the tropical storm
should be in an environment otherwise conducive for strengthening
for at least a day or two. Octave's relatively small size could make
it susceptible to relatively quick changes in intensity, up or
down. All of the traditional dynamical intensity models forecast
that Octave will change little in strength during that period. On
the other hand, Google DeepMind (GDM) ensemble shows a very
different story with an unusually large range of possibilities
between tropical depression and major hurricane strength. The NHC
forecast has not been changed, and is on the high end of the
traditional guidance, but below the GDM ensemble mean. Because of
this discrepancy, confidence in the intensity forecast is low,
despite the fact that no changes were made to the NHC forecast with
this advisory.


FORECAST POSITIONS AND MAX WINDS

INIT  03/1500Z 13.4N 121.0W   45 KT  50 MPH
12H  04/0000Z 13.8N 122.0W   45 KT  50 MPH
24H  04/1200Z 14.4N 123.2W   45 KT  50 MPH
36H  05/0000Z 15.0N 123.9W   50 KT  60 MPH
48H  05/1200Z 15.4N 124.1W   55 KT  65 MPH
60H  06/0000Z 15.6N 123.7W   55 KT  65 MPH
72H  06/1200Z 15.7N 123.0W   50 KT  60 MPH
96H  07/1200Z 15.4N 121.2W   40 KT  45 MPH
120H  08/1200Z 15.0N 119.0W   35 KT  40 MPH

$$
Forecaster D. Zelinsky

ygsj24

927
WTPZ45 KNHC 032035
TCDEP5

Tropical Storm Octave Discussion Number  15
NWS National Hurricane Center Miami FL       EP152025
200 PM PDT Fri Oct 03 2025

While Octave's overall appearance has remained steady since this
morning, its center appears to be just embedded enough within the
central dense overcast produced by its convection for recent
subjective Dvorak estimates to come up to T3.5 or 55 kt. Objective
intensity estimates are still a little lower, so the intensity has
been nudged up slightly to 50 kt for this advisory. There was no
useful ASCAT data available for this afternoon's analysis, but
earlier SAR data also generally supported an intensity near 50 kt
with wind radii similar to what NHC previously analyzed.

No changes of note were made to the NHC track or intensity
forecasts, but both aspects of the forecast remain highly uncertain,
especially beyond the next 24 hours. Octave should still continue
west-northwestward for another day or so, before it slows down and
turns northward. Next week Octave will likely begin moving slowly
eastward, but exactly how fast and how far north it moves before
will depend on how much Octave interacts with a trough well to its
north and a large disturbance developing to its east. The NHC track
forecast is still near the middle of the multi-model and
single-model ensemble envelopes but confidence in the forecast has
not increased, especially beyond 72 hours.

Similarly, Octave's intensity will probably change little for the
next 12 to 24 hours. After that, it will have a brief period of a
day or so where the shear is expected to lessen and the cyclone
could intensity further. The Google DeepMind Ensemble Mean continues
to be an outlier in showing Octave reaching hurricane strength, but
the ensemble shows that there is a wide range of possibilities from
a near steady-state tropical storm to a strong hurricane. The
official forecast is still on the high end of the other intensity
guidance, but is lower than the GDM mean. By the end of the
forecast period, Octave will likely weaken as it interacts with the
much larger disturbance currently located to its east.


FORECAST POSITIONS AND MAX WINDS

INIT  03/2100Z 13.7N 121.7W   50 KT  60 MPH
12H  04/0600Z 14.1N 122.8W   50 KT  60 MPH
24H  04/1800Z 14.7N 123.7W   50 KT  60 MPH
36H  05/0600Z 15.2N 124.1W   55 KT  65 MPH
48H  05/1800Z 15.6N 123.8W   55 KT  65 MPH
60H  06/0600Z 15.7N 123.4W   50 KT  60 MPH
72H  06/1800Z 15.7N 122.5W   50 KT  60 MPH
96H  07/1800Z 15.2N 120.5W   40 KT  45 MPH
120H  08/1800Z 15.0N 118.0W   35 KT  40 MPH

$$
Forecaster D. Zelinsky

ygsj24

000
WTPZ45 KNHC 040233
TCDEP5

Tropical Storm Octave Discussion Number  16
NWS National Hurricane Center Miami FL       EP152025
800 PM PDT Fri Oct 03 2025

Octave still has the appearance of a sheared tropical cyclone.
Infrared geostationary satellite imagery shows that cloud top
temperatures have generally warmed over the past few hours. Similar
to the previous night, isolated bursts of convection are
currently forming within the western portion of the circulation.
This can also be seen on an AMSR2 microwave pass from earlier
this afternoon that had a fragmented curved band wrapping around
the southern and western sides of Octave.  The initial intensity is
held at 50 kt, representing a blend of the subjective and objective
Dvorak estimates that range between 39 to 55 kt.

The tropical storm is still moving west-northwestward at 7 kt.  
Octave is expected to turn more to the northwest soon, followed by
a northward motion on Sunday with a decreased forward speed as the
mid-level ridge to the east weakens.  By early next week, the
cyclone should begin to move eastward, but the track guidance
envelope is quite large by the middle-to-latter portions of the
forecast period.  This is because models differ on how much Octave
will interact with a trough over the western United States and how
quickly a developing disturbance (Invest 99-E) will organize.  The
only changes to the latest NHC track forecast are that it lies
slightly south and west of the previous forecast in the first 36 h,
due the delayed turn to the northwest.

Vertical wind shear is gradually relaxing over the cyclone which
could lead to some slight strengthening in about a day.  Most of the
reliable models are no longer showing Octave becoming a hurricane.  
By 48 h, the vertical wind shear is expected to increase and
gradually weaken the cyclone as it moves eastward towards the much
larger system to its east.  Only minor adjustments have been made
to the official intensity forecast, which lies in the middle of the
guidance suite.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0300Z 13.8N 122.7W   50 KT  60 MPH
12H  04/1200Z 14.2N 123.5W   50 KT  60 MPH
24H  05/0000Z 14.8N 124.2W   55 KT  65 MPH
36H  05/1200Z 15.3N 124.2W   55 KT  65 MPH
48H  06/0000Z 15.5N 123.9W   55 KT  65 MPH
60H  06/1200Z 15.7N 123.1W   50 KT  60 MPH
72H  07/0000Z 15.5N 121.8W   45 KT  50 MPH
96H  08/0000Z 15.0N 120.0W   40 KT  45 MPH
120H  09/0000Z 14.8N 117.2W   35 KT  40 MPH

$$
Forecaster Bucci

pocketbox

全球热带气旋监测公报
预报：徐润杰、刘涛  签发：董 林  2025 年 10 月 04 日 10 时
“奥克塔夫”向西偏北方向移动

时        间:     4日08时（北京时，下同）

海        域:    东北太平洋

命        名:    “奥克塔夫”，OCTAVE

中心位置:    北纬13.6度，西经122.4度

强度等级:    热带风暴

最大风力:    10级，26米/秒，相当于我国的强热带风暴级

中心气压:    1000百帕

参考位置:    距离墨西哥南下加利福尼亚州圣卢卡斯角西南方向约1670公里

变化过程:    过去24小时，“奥克塔夫”强度维持

预报结论:   “奥克塔夫”将以每小时10-15公里的速度向西偏北方向移动，强度维持



图1 卫星红外监测图像（北京时间2025年10月4日08时00分）

ygsj24

513
WTPZ45 KNHC 040841
TCDEP5

Tropical Storm Octave Discussion Number  17
NWS National Hurricane Center Miami FL       EP152025
200 AM PDT Sat Oct 04 2025

Octave is still trying to become better organized this morning, as
shear starts to decrease over the system. In recent satellite
images, a large convective band has started to become better
established on the western side of the system with cold cloud tops
near -80 C. However, recent satellite-derived winds depicted peak
winds of only 34 kt, although it did not sample the convective band
to the west. Subjective and objective satellite intensity estimates
have held steady and range from 45 to 55 kt. Using a blend of these
estimates and the lower satellite derived wind speeds, the intensity
is lowered to 45 kt for this advisory.

The storm is moving west-northwest at an estimated motion of 290/7
kt. Octave should gradually turn towards the northwest later today,
followed by a northward turn on Sunday with a decrease in forward
speed as steering currents weaken. In about 48 h, there continue to
be differences within the track guidance envelope and it is due to
how much interaction occurs with a trough to the north of the system
and a developing disturbance (Invest 99E) to the east. The latest
NHC track forecast is similar to the previous in the short-term, but
is slightly faster with the eastward motion closest to the HCCA and
Google DeepMind solutions.

Wind shear has started to decrease over the system, with marginally
warm sea surface temperatures near 27 C along the forecast track.
Thus, slight intensification is possible over the next day or two.
By 48 h, the vertical wind shear is expected to increase and a
weakening trend is forecast as it interacts with a much larger
system to the east. The NHC intensity forecast is near the previous,
showing some slight strengthening possible, although a lower peak
intensity and lies near the simple intensity consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z 14.2N 123.2W   45 KT  50 MPH
12H  04/1800Z 14.6N 123.9W   50 KT  60 MPH
24H  05/0600Z 15.2N 124.1W   50 KT  60 MPH
36H  05/1800Z 15.6N 123.8W   50 KT  60 MPH
48H  06/0600Z 15.8N 123.0W   45 KT  50 MPH
60H  06/1800Z 15.9N 121.9W   40 KT  45 MPH
72H  07/0600Z 15.5N 120.5W   35 KT  40 MPH
96H  08/0600Z 15.0N 118.5W   30 KT  35 MPH
120H  09/0600Z 15.6N 115.2W   30 KT  35 MPH

$$
Forecaster Kelly