EPAC: SONIA - Remnants - Discussion

[Sciencerocks]

Getting hit with southerly shear. Probably won't be strengthen much...

[cycloneye]

Tropical Storm Sonia Discussion Number 9
NWS National Hurricane Center Miami FL EP182025
200 PM PDT Sun Oct 26 2025

Visible satellite imagery and a recent ASCAT-B scatterometer pass
show that the low-level center was slightly further east than the
previous advisory, on the southeastern side of the convection.
Convection has been waning over the last few hours, with warming
cloud tops. The latest satellite intensity estimates range from 30
to 44 kt, and the peak satellite derived winds from ASCAT-B were 36
kt. Using this data, the initial intensity is held at 40 kt for this
advisory. The wind radii have been adjusted and refined with the
scatterometer data.

Sonia is moving slowly west-northwestward at an estimated motion of
295/03 kt. This west-northwest motion at a slightly faster forward
speed is anticipated over the next day or so. Once the system begins
to weaken, the storm will turn back towards the west steered by the
low-level wind flow. The latest NHC track forecast lies near the
previous, between the HCCA corrected consensus and Google DeepMind
aids.

Sonia continues to deal with moderate southerly wind shear, which
will increase over the next couple of days. The latest sea surface
temperature analysis shows that the system is moving into sub 27C
ocean temperatures, with even cooler SSTs, and a drier more stable
airmass along the forecast track. Given the latest satellite trends
and the less than favorable environmental conditions, intensity aids
show a gradual weakening trend. The GFS and ECMWF model simulated IR
satellite shows that the system will struggle to produce enough
convection to be categorized as a tropical system by 60h. The latest
NHC intensity forecast follows these trends and lies near the
consensus aids, becoming a remnant low in 60h and then dissipating
by day 4.


FORECAST POSITIONS AND MAX WINDS

INIT 26/2100Z 13.8N 119.8W 40 KT 45 MPH
12H 27/0600Z 14.1N 120.3W 40 KT 45 MPH
24H 27/1800Z 14.3N 121.4W 35 KT 40 MPH
36H 28/0600Z 14.5N 122.6W 35 KT 40 MPH
48H 28/1800Z 14.7N 124.0W 30 KT 35 MPH
60H 29/0600Z 14.7N 125.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 29/1800Z 14.5N 127.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 30/1800Z...DISSIPATED

$$
Forecaster Kelly

[cycloneye]

BULLETIN
Tropical Storm Sonia Advisory Number 10
NWS National Hurricane Center Miami FL EP182025
800 PM PDT Sun Oct 26 2025

...SONIA HOLDING STEADY...

SUMMARY OF 800 PM PDT...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...14.1N 120.0W
ABOUT 895 MI...1445 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Sonia Discussion Number 10
NWS National Hurricane Center Miami FL EP182025
800 PM PDT Sun Oct 26 2025

Satellite imagery indicates that Sonia has degraded during the past
12 to 24 h as persistent moderate southerly wind shear has displaced
deep convection mostly north of the low-level circulation center.
The circulation is now partially exposed on the southern edge of the
deep convection. Based on a blend of the subjective Dvorak and
objective intensity estimates, the initial intensity is set at 40
kt.

Sonia is moving west-northwestward at about 295/5 kt, and this
general motion is expected to persist over the next day or so, as
the subtropical ridge remains positioned to the north. By Tuesday,
Sonia should gradually turn toward the west as it becomes a shallow
system embedded within the low-level trade-wind flow. The NHC track
forecast is little changed from the previous one and remains close
to the multi-model consensus aids.

Moderate southerly wind shear continues to affect Sonia and is
expected to generally hold steady during the next couple of days, if
not increase slightly. This, combined with cooler waters and a
drier, more stable environment ahead of the cyclone, should result
in a gradual weakening trend beginning within the next 12 to 24
hours. Simulated satellite imagery from the GFS and ECMWF shows
convection diminishing significantly by Tuesday, suggesting that
Sonia will lose organized deep convection and become a post-tropical
remnant low by that time. Dissipation is expected by Wednesday as
the remnant low continues westward and opens into a trough. The
updated NHC intensity forecast closely follows the consensus aids
and remains similar to the previous one.


FORECAST POSITIONS AND MAX WINDS

INIT 27/0300Z 14.1N 120.0W 40 KT 45 MPH
12H 27/1200Z 14.3N 120.6W 40 KT 45 MPH
24H 28/0000Z 14.6N 121.7W 35 KT 40 MPH
36H 28/1200Z 14.8N 123.2W 35 KT 40 MPH
48H 29/0000Z 14.8N 124.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 29/1200Z 14.7N 126.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 30/0000Z...DISSIPATED

$$
Forecaster Gibbs (CPHC)

[cycloneye]

BULLETIN
Tropical Storm Sonia Advisory Number 11
NWS National Hurricane Center Miami FL EP182025
200 AM PDT Mon Oct 27 2025

...SONIA HOLDING STEADY WHILE MOVING WEST-NORTHWESTWARD...


SUMMARY OF 200 AM PDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...14.2N 120.6W
ABOUT 920 MI...1485 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES





Tropical Storm Sonia Discussion Number 11
NWS National Hurricane Center Miami FL EP182025
200 AM PDT Mon Oct 27 2025

Satellite imagery shows a renewed burst of deep convection over and
just north of the low-level circulation center during the past
several hours, despite the steady southerly wind shear affecting it.
Based on a blend of the subjective Dvorak and objective intensity
estimates, the initial intensity is held at 40 kt.

The initial motion is west-northwestward at about 285/6 kt, and this
general motion is expected to persist today, as the subtropical
ridge remains positioned to the north. By Tuesday, Sonia should
gradually turn toward the west as it becomes a shallow system
embedded within the low-level trade-wind flow. The NHC track
forecast is little changed from the previous one and remains close
to the multi-model consensus aids.

Although Sonia has been able to regenerate convection and may
continue to do so intermittently during the next day or so, the
unfavorable environment surrounding the system is expected to begin
taking its toll soon. Moderate southerly shear, marginal sea-surface
temperatures, and a drier, more stable environment along the
forecast path should cause a weakening trend to begin by tonight.
Simulated satellite imagery from the global models shows convection
steadily diminishing by Tuesday, and Sonia is forecast to become a
post-tropical remnant low by that time. Dissipation is expected to
occur by midweek as the remnant low opens into a trough. The updated
NHC intensity forecast is unchanged from the previous one and
remains close to the consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 27/0900Z 14.2N 120.6W 40 KT 45 MPH
12H 27/1800Z 14.4N 121.5W 40 KT 45 MPH
24H 28/0600Z 14.6N 122.7W 35 KT 40 MPH
36H 28/1800Z 14.8N 124.2W 35 KT 40 MPH
48H 29/0600Z 14.8N 125.8W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 29/1800Z 14.7N 127.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 30/0600Z...DISSIPATED

$$
Forecaster Gibbs (CPHC)

[cycloneye]

BULLETIN
Tropical Storm Sonia Advisory Number 12
NWS National Hurricane Center Miami FL EP182025
800 AM PDT Mon Oct 27 2025

...SHEARED SONIA MOVING WESTWARD..


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...13.8N 121.1W
ABOUT 965 MI...1555 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Sonia Discussion Number 12
NWS National Hurricane Center Miami FL EP182025
800 AM PDT Mon Oct 27 2025

Satellite images show that the low-level center is exposed, with
southerly wind shear causing convection to be displaced to the
north. Satellite intensity estimates range between 35 to 45 kt,
thus the initial intensity is held at 40 kt for this advisory.

The system looks to have turned back towards the west at an
estimated motion of 275/6 kt. This general motion should continue as
the system weakens and becomes more shallow, and steered by the
low-level wind flow. The NHC track was nudged slightly south
towards the HCCA corrected consensus and Google DeepMind solution.

Sonia is moving into an increasingly unfavorable environment. Wind
shear is expected to increase, with cooling SSTs, and drier air
along the forecast track. This should lead to a gradual weakening
trend, and model simulated IR satellite shows convection diminishing
by Tuesday. The latest NHC forecast follows these trends with the
system becoming a post-tropical remnant low in 36 h. The system is
forecast to dissipate and open into a trough in two to three days.

FORECAST POSITIONS AND MAX WINDS

INIT 27/1500Z 13.8N 121.1W 40 KT 45 MPH
12H 28/0000Z 13.9N 122.0W 40 KT 45 MPH
24H 28/1200Z 14.1N 123.4W 35 KT 40 MPH
36H 29/0000Z 14.2N 124.9W 30 KT 35 MPH...POST-TROPICAL
48H 29/1200Z 14.2N 126.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 30/0000Z 14.0N 128.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 30/1200Z...DISSIPATED

$$
Forecaster Kelly

[cycloneye]

BULLETIN
Tropical Storm Sonia Advisory Number 13
NWS National Hurricane Center Miami FL EP182025
200 PM PDT Mon Oct 27 2025

...SONIA MOVING WESTWARD...


SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...14.1N 121.6W
ABOUT 975 MI...1570 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES



Tropical Storm Sonia Discussion Number 13
NWS National Hurricane Center Miami FL EP182025
200 PM PDT Mon Oct 27 2025

Sonia is producing only intermittent convection over the low-level
center. Previous convection that was displaced well north of the
center has dissipated. Latest satellite intensity estimates have
decreased and range from 30 to 35 kt from SAB, TAFB and UW-CIMSS.
Using these estimates and the current satellite presentation, the
initial intensity is lowered to 35 kt for this advisory.

The storm is moving westward at an estimated motion of 275/6 kt.
This general motion should continue as the system weakens and is
steered by the low-level wind flow. The latest NHC track forecast is
near the previous, only nudged slightly to the right towards the
HCCA and Google DeepMind solutions.

Moderate wind shear, and a drier more stable airmass have taken
their toll on Sonia today. The GFS model simulated IR satellite
shows that the system will not produce anymore convection, while the
ECMWF shows a burst occuring later this evening or tonight. The
latest NHC forecast shows the system becoming a post-tropical
remnant low in 24 h, although that could occur sooner if organized
deep convection does not return over the low-level center tonight.
The system is forecast to dissipate and open into a trough in about
two to three days.


FORECAST POSITIONS AND MAX WINDS

INIT 27/2100Z 14.1N 121.6W 35 KT 40 MPH
12H 28/0600Z 14.2N 122.5W 30 KT 35 MPH
24H 28/1800Z 14.5N 124.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 29/0600Z 14.7N 125.7W 25 KT 30 MPH...POST-TROPICAL
48H 29/1800Z 14.6N 127.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 30/0600Z...DISSIPATED

$$
Forecaster Kelly

[cycloneye]

BULLETIN
Tropical Storm Sonia Advisory Number 14
NWS National Hurricane Center Miami FL EP182025
800 PM PDT Mon Oct 27 2025

...SONIA REMAINS A TROPICAL STORM...


SUMMARY OF 800 PM PDT...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...14.5N 122.2W
ABOUT 990 MI...1595 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES




Tropical Storm Sonia Discussion Number 14
NWS National Hurricane Center Miami FL EP182025
800 PM PDT Mon Oct 27 2025

The satellite presentation of Sonia has changed little since the
previous advisory, with a small area of deep convection persisting
over the low-level center. The latest subjective Dvorak current
intensity estimates from TAFB and SAB are 2.5/35 kt and 2.0/30 kt,
respectively, while objective estimates from UW-CIMSS have ranged
from 31 to 41 kt. A blend of these data, along with an earlier
ASCAT Metop-C pass that sampled a broad area of 30-33 kt winds when
convection was absent, supports maintaining the initial intensity at
35 kt for this advisory.

Sonia is moving west-northwestward, or 295 degrees at 6 kt. A turn
toward the west is expected later tonight or Tuesday as the
circulation becomes shallower and the system is steered along by the
low-level flow. The official forecast track has been nudged
slightly north of the previous one due to the more west-northwest
motion observed since the last advisory, and it lies close to the
Google DeepMind ensemble mean.

Sonia’s days appear to be numbered, as the cyclone remains affected
by strong southerly shear—currently analyzed near 25 kt by UW-CIMSS.
The shear is expected to increase slightly over the next day or so
while Sonia moves over gradually cooling waters and into a drier
mid-level environment. These factors should result in a steady
weakening trend, with the system likely to become a post-tropical
remnant low on Wednesday and dissipate on Thursday. The intensity
forecast has been adjusted slightly higher than the previous
advisory, based on recent satellite trends and the latest consensus
guidance.


FORECAST POSITIONS AND MAX WINDS

INIT 28/0300Z 14.5N 122.2W 35 KT 40 MPH
12H 28/1200Z 14.7N 123.2W 35 KT 40 MPH
24H 29/0000Z 14.9N 124.8W 30 KT 35 MPH
36H 29/1200Z 15.0N 126.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 30/0000Z 14.9N 128.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 30/1200Z...DISSIPATED

$$
Forecaster Jelsema (CPHC)

[cycloneye]

Tropical Storm Sonia Discussion Number 15
NWS National Hurricane Center Miami FL EP182025
200 AM PDT Tue Oct 28 2025

The satellite presentation of Sonia has changed little since the
previous advisory, with a small area of deep convection persisting
over or near the cyclone’s low-level center. The latest subjective
Dvorak current intensity estimates from TAFB and SAB are 2.0/30 kt
and 1.5/25 kt, respectively, while objective estimates from UW-CIMSS
range from 33 to 38 kt. A timely 0507 UTC Metop-C ASCAT pass
revealed a swath of 35-kt winds, with a peak vector of 36 kt. Taking
into account possible undersampling in the satellite-derived winds
and the persistence of convection over or near the center for
roughly 12 hours, the initial intensity is raised to 40 kt for this
advisory.

Sonia is moving west-northwest, or 300 degrees, at 7 kt. A turn
toward the west is expected later today as Sonia’s circulation
becomes shallower and is steered by the low-level flow. The NHC
forecast has been nudged slightly north of the previous track,
reflecting the continued west-northwest motion observed since the
last advisory. The forecast track lies closest to a blend of the
HFIP Corrected Consensus and Google DeepMind ensemble mean guidance.

Sonia’s days appear to be numbered as the cyclone continues to be
affected by moderate to strong southerly wind shear, analyzed near
22 kt by UW-CIMSS. The shear is expected to increase slightly
within about 12 hours, while Sonia moves over gradually cooling
waters and into a drier mid-level environment. Simulated satellite
imagery from the GFS and ECMWF indicates that deep convection should
collapse in about 12 hours under these increasingly hostile
conditions. This is expected to result in gradual weakening, with
Sonia forecast to become a post-tropical remnant low tonight and
dissipate on Thursday. The intensity forecast is unchanged from the
previous advisory and remains close to a blend of the latest
consensus and SHIPS guidance.


FORECAST POSITIONS AND MAX WINDS

INIT 28/0900Z 14.8N 122.8W 40 KT 45 MPH
12H 28/1800Z 15.0N 123.9W 35 KT 40 MPH
24H 29/0600Z 15.1N 125.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 29/1800Z 15.0N 127.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 30/0600Z 14.6N 129.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 30/1800Z...DISSIPATED

$$
Forecaster Jelsema (CPHC)

[cycloneye]

Tropical Storm Sonia Discussion Number 16
NWS National Hurricane Center Miami FL EP182025
800 AM PDT Tue Oct 28 2025

Sonia remains a sheared tropical cyclone with a large area of deep
convection located to the northwest of the low-level center. There
is little banding evident in conventional and recent microwave
imagery. The initial intensity remains 40 kt, which is based
primarily on earlier scatterometer data and a Dvorak T-number of 2.5
from TAFB. Moderate to strong southern shear is expected to persist
during the next couple of days while Sonia moves over gradually
decreasing SSTs and into a drier mid-level environment. These
negative factors are expected to result in weakening and
degeneration into a remnant low within 24 hours. The circulation is
forecast by the global models to open up into a trough in about 48
hours, therefore dissipation is shown at that time.

Sonia is moving west-northwestward, or 290 degrees, at 7 kt. A turn
toward the west is expected later today as the cyclone becomes
vertically shallow. The updated NHC track is a blend of the latest
Google DeepMind ensemble mean and the simple consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 28/1500Z 15.1N 123.5W 40 KT 45 MPH
12H 29/0000Z 15.2N 124.7W 30 KT 35 MPH
24H 29/1200Z 15.3N 126.5W 30 KT 35 MPH...POST-TROPICAL
36H 30/0000Z 15.1N 128.6W 25 KT 30 MPH...POST-TROPICAL
48H 30/1200Z...DISSIPATED

$$
Forecaster Brown

[cycloneye]

BULLETIN
Tropical Storm Sonia Advisory Number 17
NWS National Hurricane Center Miami FL EP182025
200 PM PDT Tue Oct 28 2025

...SONIA WEAKENING, FORECAST TO BECOME A REMNANT LOW
TONIGHT...


SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...15.3N 124.3W
ABOUT 1075 MI...1730 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES



Tropical Storm Sonia Discussion Number 17
NWS National Hurricane Center Miami FL EP182025
200 PM PDT Tue Oct 28 2025

The center of Sonia has become exposed on the southern side of a
decreasing area of deep convection. A scatterometer pass indicated
lower winds (30-35 kt) within the circulation than the overnight
pass, and conventional satellite estimates are also decreasing.
Thus, the initial intensity is reduced to 35 kt.

Sonia is moving west-northwestward at 8 kt through an increasingly
dry and sheared environment across cooler SSTs. Further slow
weakening is anticipated while the system turns westward due to the
low-level flow. Global models suggest that Sonia has produced its
last organized convective burst, which is consistent with the
unfavorable environment. Therefore, remnant low status is shown in
12 hours. The updated NHC track and intensity forecast is very
similar to the previous one and the consensus/corrected-consensus
aids. The circulation is still forecast by the global models to
open up into a trough in about 48 hours, therefore dissipation is
shown at that time.


FORECAST POSITIONS AND MAX WINDS

INIT 28/2100Z 15.3N 124.3W 35 KT 40 MPH
12H 29/0600Z 15.4N 125.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
24H 29/1800Z 15.3N 127.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 30/0600Z 15.0N 130.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 30/1800Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

Tropical Storm Sonia Discussion Number 18
NWS National Hurricane Center Miami FL EP182025
800 PM PDT Tue Oct 28 2025

Sonia appears to have finally succumbed to the strong southerly
shear analyzed by UW-CIMSS to be near 26 kt, while moving over
cooler waters below 26C and into a drier mid-level environment with
humidity values below 50 percent. Deep convection was sheared away
from the center around or shortly after 1800 UTC and has not
returned, indicating that Sonia’s time as a tropical cyclone is
nearly over. The latest subjective Dvorak current intensity
estimates from TAFB and SAB are 2.5/35 kt and 2.0/30 kt,
respectively, while objective estimates from UW-CIMSS range from 28
to 39 kt. Based on a blend of these data, the initial intensity for
this advisory is held at, perhaps a generous, 35 kt.

Sonia is now moving westward, or 280 degrees at 8 kt. This general
motion is expected to continue through dissipation. The official
track forecast is very similar to the previous one and represents a
blend of the HCCA, GDMI, and FSSE track aids.

Strong southerly shear is expected to persist during the next day or
so while Sonia remains over cool waters of 25–26C and within dry
mid-level air below 50 percent. As a result, gradual weakening is
anticipated, and Sonia is forecast to become a post-tropical remnant
low later tonight and dissipate by Thursday. The intensity forecast
is unchanged from the previous advisory and remains closely aligned
with the various intensity consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 29/0300Z 15.4N 125.3W 35 KT 40 MPH
12H 29/1200Z 15.4N 126.9W 30 KT 35 MPH...POST-TROP/REMNT LOW
24H 30/0000Z 15.2N 129.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 30/1200Z 14.8N 131.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 31/0000Z...DISSIPATED

$$
Forecaster Jelsema (CPHC)

[cycloneye]

BULLETIN
Post-Tropical Cyclone Sonia Advisory Number 19
NWS National Hurricane Center Miami FL EP182025
200 AM PDT Wed Oct 29 2025

...SONIA WEAKENS INTO A POST-TROPICAL REMNANT LOW...


SUMMARY OF 200 AM PDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...15.3N 126.1W
ABOUT 1180 MI...1895 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES




Post-Tropical Cyclone Sonia Discussion Number 19
NWS National Hurricane Center Miami FL EP182025
200 AM PDT Wed Oct 29 2025

Sonia has succumbed to hostile environmental conditions, with
satellite imagery showing no deep convection near the low-level
center for about 15 hours. Therefore, Sonia is being a declared
post-tropical cyclone. The latest subjective satellite intensity
estimates from TAFB and SAB reflect this, deeming the system too
weak to classify. A 0541 UTC Metop-B ASCAT pass revealed a large
area of 25-kt winds, with a peak wind vector of 26 kt. Taking into
account the likelihood of some undersampling, the initial intensity
for the post-tropical remnant low of Sonia is set at 30 kt.

Sonia will continue moving westward during the next day or so,
steered by the low-level flow, while remaining embedded within a
hostile environment. Regeneration of organized deep convection is
not expected, and the remnant low of Sonia is forecast to dissipate
by Thursday, if not sooner.

For additional information on the post-tropical remnant low please
see High Seas Forecasts issued by the National Weather Service,
under AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and on the
web at ocean.weather.gov/shtml/NFDHSFEPI.php

FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 15.3N 126.1W 30 KT 35 MPH...POST-TROPICAL
12H 29/1800Z 15.2N 127.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 30/0600Z 14.7N 129.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 30/1800Z...DISSIPATED

$$
Forecaster Jelsema (CPHC)

[Teban54]

Poor Sonia, getting outshined by Melissa during her entire life.

Before this comment, this entire page of 12 comments had no images, and only one that was not an advisory.