EPAC: NEWTON - Post-Tropical

[Subtrop]

EP, 96, 2022092100, , BEST, 0, 167N, 1021W, 25, 1008, DB, 34, NEQ, 0, 0, 0, 0, 1010, 100, 50, 0, 0, E, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 025, SPAWNINVEST, ep772022 to ep962022,

https://ftp.nhc.noaa.gov/atcf/btk/

[Sciencerocks]

[Yellow Evan]

One of many tropical cyclones around the world.

[Yellow Evan]

South of Southwestern Mexico:
Showers and thunderstorms have increased in association with a broad
area of low pressure located just off the coast of southwestern
Mexico. Environmental conditions appear generally conducive for
additional development and a tropical depression is likely to form
over the next day or two. This system is expected to move
west-northwestward near or just south of southwestern Mexico over
the next day or so, and then away from the coast of Mexico through
the end of the week.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...70 percent.

[Yellow Evan]

101
ABPZ20 KNHC 211754
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
Issued by the NWS Weather Prediction Center College Park MD
1100 AM PDT Wed Sep 21 2022

For the eastern North Pacific...east of 140 degrees west longitude:

South of Southwestern Mexico:
Showers and thunderstorms associated with a broad area of low
pressure just offshore of southwestern Mexico have changed little
in organization today. A short-lived tropical depression is likely
to form during the next day or so before the system moves over
cooler waters and into a drier environment. This system is expected
to move west-northwestward just south of southwestern Mexico over
the next day or so, and then move away from the coast of Mexico.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Cangialosi/Wegman/Carbin

[Sciencerocks]

[Sciencerocks]

000
WTPZ45 KNHC 212042
TCDEP5

Tropical Depression Fifteen-E Discussion Number 1
NWS National Hurricane Center Miami FL EP152022
400 PM CDT Wed Sep 21 2022

A new tropical depression has formed in the east Pacific basin.
The satellite presentation of now Tropical Depression Fifteen-E
has improved over the past 24 hours. Visible imagery shows decent
upper-level outflow in the western semicircle and cold cloud tops as
low as -70 degrees C. Due to the increase in convective
organization, the initial intensity is set to 30 kt, slightly
higher than the subjective Dvorak estimates from TAFB and SAB.

The depression is moving just north of west at 275/9 kt. It is
moving along the southwest periphery of a mid-level ridge centered
over Texas. This ridge is expected to steer the system to the
west-northwest for the next couple of days at a gradually slower
forward speed. The model guidance is relatively tightly
clustered and the NHC track forecast is close to the multi-model
consensus aids.

The environmental conditions are forecast to be marginally
conducive for slight development over the next couple days.
Oceanic surface temperatures, atmospheric moisture and vertical
wind shear are likely to allow the depression to reach and maintain
tropical cyclone strength for the next couple of days. Beyond that
time frame, the cyclone is forecast to traverse cooler waters and
enter a drier, more stable environment. The system is expected to
become a remnant low by 72 hours and open into a trough shortly
thereafter.


FORECAST POSITIONS AND MAX WINDS

INIT 21/2100Z 17.1N 105.3W 30 KT 35 MPH
12H 22/0600Z 17.5N 106.4W 35 KT 40 MPH
24H 22/1800Z 17.8N 107.8W 35 KT 40 MPH
36H 23/0600Z 17.9N 108.9W 35 KT 40 MPH
48H 23/1800Z 18.2N 110.0W 35 KT 40 MPH
60H 24/0600Z 18.5N 111.5W 30 KT 35 MPH
72H 24/1800Z 18.9N 112.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 25/1800Z...DISSIPATED

$$
Forecaster Bucci/Jelsema

[Yellow Evan]

[cycloneye]

Newton.

EP, 15, 2022092200, , BEST, 0, 175N, 1066W, 40, 1004, TS, 34, NEQ, 50, 0, 0, 50, 1010, 100, 30, 0, 0, E, 0, , 0, 0, NEWTON, M

https://ftp.nhc.noaa.gov/atcf/btk/bep152022.dat

[Kingarabian]

Looks like it's 60kts...

[cycloneye]

Tropical Storm Newton Tropical Cyclone Update
NWS National Hurricane Center Miami FL EP152022
755 PM CDT Wed Sep 21 2022

...DEPRESSION BECOMES TROPICAL STORM NEWTON...

Satellite images indicate that Tropical Depression Fifteen-E has
strengthened and is now Tropical Storm Newton with maximum
sustained winds of 45 mph (75 km/h) with higher gusts. This
intensity will be accounted for in the advisory being released at
1000 pm CDT (0300 UTC).

SUMMARY OF 755 PM CDT...0050 UTC...INFORMATION
----------------------------------------------
LOCATION...17.5N 106.6W
ABOUT 175 MI...280 KM SW OF MANZANILLO MEXICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES

$$
Forecaster Berg/Jelsema

[Sciencerocks]

[img]
000
WTPZ45 KNHC 220245
TCDEP5

Tropical Storm Newton Discussion Number 2
NWS National Hurricane Center Miami FL EP152022
900 PM MDT Wed Sep 21 2022

The satellite presentation of the recently formed Tropical
Depression Fifteen has improved considerably during the past 24
hours. A well defined banding structure has developed and held in
place during the past several hours, with nice outflow evident
aloft in satellite imagery. The latest intensity estimates from TAFB
and SAB were 35 knots, while ADT and AiDT from UW-CIMSS indicating
slightly lower. These intensity estimates appear to be a bit behind
the curve given the banding structure and organization seen in
recent microwave imagery. In fact, TAFB provided a Dvorak pattern
T-number of 3.0 (45 kt), which is the basis for the initial
intensity of this advisory.

The initial motion estimate on Newton is to the west-northwest
or 285/11 kt. This general motion with a gradual slowing in the
forward speed is expected during the next several days as the
cyclone is steered by a mid-level ridge to the northeast and a
weakness aloft to the west associated with the remnants of former
tropical cyclone Madeline. The NHC track forecast was adjusted
slightly faster and a bit north of the previous forecast, and is
close to the tightly clustered consensus track guidance.

Environmental conditions appear favorable for some additional
strengthening tonight and Wednesday, as vertical wind shear remains
low, mid-levels moist, and sea surface temperatures (SSTs) remain at
27/28C. Beyond this, while shear remains low, the mid-levels dry out
considerably and SSTs decrease to near 26C. This should lead to
steady weakening with Newton degenerating into a post-tropical
remnant low Friday night or Saturday, and dissipating shortly
thereafter. The NHC intensity forecast has been adjusted upward to
account for the increase in initial intensity, and is roughly
between the statistical and dynamical intensity aids.


FORECAST POSITIONS AND MAX WINDS

INIT 22/0300Z 17.6N 107.0W 45 KT 50 MPH
12H 22/1200Z 18.0N 108.2W 50 KT 60 MPH
24H 23/0000Z 18.3N 109.6W 50 KT 60 MPH
36H 23/1200Z 18.6N 110.7W 50 KT 60 MPH
48H 24/0000Z 18.9N 111.9W 40 KT 45 MPH
60H 24/1200Z 19.3N 113.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 25/0000Z...DISSIPATED

$$
Forecaster Brown/Jelsema
[/img]

[Sciencerocks]

[Yellow Evan]

TXPZ27 KNES 220550
TCSENP

A. 15E (NEWTON)

B. 22/0530Z

C. 17.5N

D. 107.1W

E. THREE/GOES-W

F. T2.5/2.5

G. IR/EIR/SWIR

H. REMARKS...5/10 BANDING RESULTS IN A DT OF 2.5. MET IS 1.5 AND PT IS
2.0 BASED ON RAPID 24-HOUR DEVELOPMENT. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...CLARK

[cycloneye]

Tropical Storm Newton Discussion Number 3
NWS National Hurricane Center Miami FL EP152022
300 AM MDT Thu Sep 22 2022

Newton is a small, but well-organized tropical cyclone. The earlier
banding pattern has now evolved more into a very small central
dense overcast. While we have not received any recent microwave or
scatterometer data in the last 6 hours, the earlier GPM pass at 2207
UTC suggested a formative inner core was taking shape. Satellite
intensity estimates cover a large range this morning, from
T2.5/35-kt from SAB, T3.5/55-kt from TAFB, and T2.8/41-kt from
UW-CIMSS ADT. Favoring the higher end of those estimates, the
initial intensity was raised to 50-kt for this advisory.

Newton continues to move to the west-northwest but is beginning to
slow down somewhat, with the latest estimate at 285/8 kt. This
general motion with an additional slow down in forward motion is
expected over the next 24-36 hours as the system remains steered by
a prominent mid-level ridge to the northeast. The NHC track this
cycle was adjusted ever so slightly faster, but remains close to
the tightly clustered consensus aids.

The intensity forecast is a bit tricky for Newton. The storm is very
small, and has not been recently sampled by scatterometer or
microwave imagery, so it is unclear if the inner core structure seen
earlier on microwave yesterday evening has persisted. Vertical wind
shear, as diagnosed by the GFS and ECMWF-based SHIPS is expected to
remain at or under 10 kts for the next 2-3 days. However, the
tropical cyclone will be moving over the cold wake induced by
Hurricane Kay and more recently Tropical Storm Madeline over the
last several weeks. Sea-surface temperatures (SSTs) drop below 26 C
in around 24 hours. The global models respond to this environment by
showing all convection collapsing near Newton in 24-48 hours and it
seems that the small circulation will not be able to survive these
anomalously cold SSTs. Then again, the cyclone is so small, the
guidance may not be resolving the current structure of the cyclone
well. Thus the latest NHC intensity forecast calls for a little bit
of additional intensification today, similar to the SHIPS guidance
in the short-term. After that, the cooler SSTs should induce a
weakening trend, and Newton is still expected to become a
post-tropical remnant low by 60 hours, continuing to blend the
dynamical and statistical intensity aids.

FORECAST POSITIONS AND MAX WINDS

INIT 22/0900Z 17.7N 107.8W 50 KT 60 MPH
12H 22/1800Z 18.0N 109.1W 55 KT 65 MPH
24H 23/0600Z 18.2N 110.5W 50 KT 60 MPH
36H 23/1800Z 18.6N 112.0W 45 KT 50 MPH
48H 24/0600Z 19.2N 113.5W 40 KT 45 MPH
60H 24/1800Z 19.3N 115.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 25/0600Z 19.3N 116.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 26/0600Z...DISSIPATED

$$
Forecaster Papin

[cycloneye]

Tropical Storm Newton Discussion Number 4
NWS National Hurricane Center Miami FL EP152022
900 AM MDT Thu Sep 22 2022

Newton remains a small, well-organized tropical cyclone. A
microwave pass from 1210 UTC revealed a tiny eye-like feature.
While the central dense overcast has warmed, upper-level outflow is
still prominent in the southern and eastern portions of the
circulation, and new deep convection continues to form in the core.
There is still a relatively large range of satellite intensity
estimates (35-55 kt), likely due to the small size of the cyclone,
but the initial intensity is raised to 55 kt with the improved
microwave structure.

The storm is moving west-northwestward at 7 kt. A ridge to the
northeast is steering Newton and should be the dominant synoptic
feature influencing the track for the next few days. The track
prediction is largely unchanged from the previous advisory and in
the center of the tightly clustered model guidance.

The intensity forecast for this system remains somewhat uncertain.
Global model guidance has largely missed the development and
intensification of Newton, again, possibly due to its size.
Statistical guidance suggests the cyclone will be in a conducive
atmospheric environment for the next 24 hours before the vertical
wind shear increases and mid-level moisture begins to decrease
further. Sea surface temperatures are expected to also gradually
decrease as Newton moves near the cold wake of Kay and Madeline.
The official intensity forecast keeps Newton at 55 kt before
weakening begins in 24 hours through the end of the forecast as
oceanic and atmospheric conditions become less favorable. The
prediction still shows Newton as a post-tropical remnant low by 72
hours.


FORECAST POSITIONS AND MAX WINDS

INIT 22/1500Z 17.9N 108.4W 55 KT 65 MPH
12H 23/0000Z 18.1N 109.5W 55 KT 65 MPH
24H 23/1200Z 18.4N 110.9W 50 KT 60 MPH
36H 24/0000Z 19.0N 112.5W 45 KT 50 MPH
48H 24/1200Z 19.4N 114.0W 40 KT 45 MPH
60H 25/0000Z 19.6N 115.5W 35 KT 40 MPH...POST-TROPICAL
72H 25/1200Z 19.8N 117.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 26/1200Z...DISSIPATED

$$
Forecaster Bucci

[Kingarabian]

Unless the CPHC is helping the NHC out, it looks like Jelsema is at the NHC now? Nice.

[cycloneye]

Tropical Storm Newton Discussion Number 5
NWS National Hurricane Center Miami FL EP152022
300 PM MDT Thu Sep 22 2022

Convection in the core of Newton has collapsed rather suddenly in
the past few hours, likely due to the ingestion of dry air. The
central dense overcast is largely gone and only small bursts of
convection are still firing near the estimated center where cloud
top temperatures are warmer than -70 degrees C. Subjective Dvorak
classification still range between 35 to 55 kt, though the objective
estimates have been declining since the previous advisory. The
initial intensity has therefore been lowered to 50 kt.

Newton continues to move west-northwestward at 285/6 kt. The
cyclone is moving along the southwest periphery of a
well-established ridge centered over Texas. This ridge will be the
main feature steering the storm until the shallow vortex turns
westward in about 3 days. The model guidance envelope has shifted
northward beyond the 36 hour forecast period. In response, the
official track forecast has been shift slightly to the right of
previous advisory after a day or so.

The small size of Newton has made it susceptible to modest changes
in the near-storm environment. Though the statistical guidance is
analyzing low vertical wind shear, the satellite presentation of the
storm would suggest a dry air intrusion has interrupted
strengthening and induced weakening. Forecast Intensity Guidance
now indicates Newton will weaken and ultimately become a remnant low
in a couple of days or so. The NHC intensity prediction no longer
shows strengthening and instead calls for gradual weakening until
dissipation at 96 hours.

FORECAST POSITIONS AND MAX WINDS

INIT 22/2100Z 18.0N 109.0W 50 KT 60 MPH
12H 23/0600Z 18.2N 110.0W 45 KT 50 MPH
24H 23/1800Z 18.7N 111.6W 45 KT 50 MPH
36H 24/0600Z 19.3N 113.2W 40 KT 45 MPH
48H 24/1800Z 19.8N 114.7W 35 KT 40 MPH
60H 25/0600Z 20.0N 116.2W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 25/1800Z 19.9N 117.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 26/1800Z...DISSIPATED

$$
Forecaster Bucci

[cycloneye]

Tropical Storm Newton Discussion Number 6
NWS National Hurricane Center Miami FL EP152022
900 PM MDT Thu Sep 22 2022

The satellite presentation of Newton has improved this evening, with
deep convection once again reforming over the low-level circulation
center. The latest satellite intensity estimates have changed little
during the past 6 hours, remaining between 35 and 55 knots, and as a
result the initial intensity will be held at 50 knots.

Newton continues to move slightly north of due west at 280/6 kt.
The cyclone is moving along the southwest periphery of a mid-level
ridge over the south-central U.S. The system is expected to continue
to track slightly north of due west during the next couple of days
as it is steered by this mid-level ridge. Drier environmental air
should ultimately lead to a collapse in deep convection over the
weekend, which should allow Newton to be steered by the low-level
flow by Sunday, with dissipation shortly thereafter. The NHC track
forecast was nudged slightly south of the previous advisory, and
lies very close to the multi-model track consensus guidance.

The environmental conditions remain conducive for maintaining deep
convection during the next day or two, before drier mid-level and
slightly stronger southerly shear begin to take more of a toll on
Newton. The intensity forecast shows little change in strength
tonight, with gradual weakening then expected until dissipation.
Newton is expected to become a post-tropical remnant low Saturday
night, if not sooner.


FORECAST POSITIONS AND MAX WINDS

INIT 23/0300Z 17.9N 109.8W 50 KT 60 MPH
12H 23/1200Z 18.2N 110.9W 50 KT 60 MPH
24H 24/0000Z 18.8N 112.5W 45 KT 50 MPH
36H 24/1200Z 19.4N 114.3W 40 KT 45 MPH
48H 25/0000Z 19.8N 116.0W 35 KT 40 MPH
60H 25/1200Z 19.7N 117.4W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 26/0000Z 19.3N 118.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 27/0000Z...DISSIPATED

$$
Forecaster Berg/Jelsema

[Sciencerocks]