EPAC: ROSLYN - Remnants

[cycloneye]

...SPECIAL FEATURE...


Offshore of Southern Mexico: Shower and thunderstorm activity
associated with a low pressure area located a couple hundred
miles south of the southern coast of Mexico continues to become
better organized. In addition, recent satellite wind data
indicates the circulation is becoming better defined.
Environmental conditions appear conducive for additional
development and a tropical depression is expected to form later
today or tonight as the system moves generally west-
northwestward, parallel to the southwestern coast of Mexico.
Interests along the southwestern and western coasts of Mexico
should monitor the progress of this system. Current winds are
20-30 kt with seas of 8-10 ft. Regardless of development,
increasing winds and building seas are expected offshore
southwestern Mexico, and a gale warning has been issued beginning
Thu afternoon, with storm conditions possible as the system
possibly rounds near Cabo Corrientes this weekend.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Wed Oct 19 2022

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

Offshore of Southwestern Mexico:
Shower and thunderstorm activity has increased and become better
organized in association with a low pressure area located a couple
of hundred miles offshore of the southwestern coast of Mexico. In
addition, the low's circulation continues to become better defined.
If these trends continue, a tropical depression is likely to form
later tonight or early Thursday as the system moves generally
west-northwestward, parallel to the southwestern coast of Mexico.
Interests along the southwestern and west-central coasts of Mexico
should monitor the progress of this system. Additional information
on this system, including gale warnings, can be found in High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 5 days...high...near 100 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Reinhart

[Yellow Evan]

Quickly organizing though I doubt winds are particularly strong yet.

[Ptarmigan]

I honestly wouldn't be surprised if this RI to a 150 mph+ hurricane.

Same here. I can see it rapid intensifying. It would be Roslyn.

[cycloneye]

EP, 90, 2022102000, , BEST, 0, 151N, 1010W, 30, 1008, LO

[Yellow Evan]

TXPZ22 KNES 192356
TCSENP

A. TROPICAL DISTURBANCE (90E)

B. 19/2330Z

C. 15.0N

D. 100.4W

E. THREE/GOES-E

F. T1.0/1.0

G. IR/EIR/VIS

H. REMARKS...>2/10 BANDING YIELDS A DT=1.0. MET AND PT AGREE. THE FT
IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...LEE

[cycloneye]

BULLETIN
Tropical Depression Nineteen-E Advisory Number 1
NWS National Hurricane Center Miami FL EP192022
1000 PM CDT Wed Oct 19 2022

...NEW TROPICAL DEPRESSION FORMS OFFSHORE OF SOUTHWESTERN MEXICO...
...EXPECTED TO STRENGTHEN DURING THE NEXT FEW DAYS...


SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.2N 101.3W
ABOUT 175 MI...280 KM S OF ZIHUATANEJO MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES




Tropical Depression Nineteen-E Discussion Number 1
NWS National Hurricane Center Miami FL EP192022
1000 PM CDT Wed Oct 19 2022

The satellite presentation of the low pressure system that the NHC
has been monitoring for the past several days has improved today,
and earlier satellite-derived wind data indicated the circulation
was becoming better defined. Since then, deep convection has
significantly increased near the low-level center, with signs of
curved banding over the northern and eastern portions of the
circulation. Based on these developments, the system now meets the
criteria of a tropical cyclone, and advisories are being initiated
on Tropical Depression Nineteen-E. The initial intensity is set at
30 kt based on a T2.0/30 kt Dvorak estimate from TAFB at 00 UTC.

The center position is somewhat uncertain given that the system just
formed, and the estimated initial motion is west-northwestward at
285/4 kt. This general motion should continue for the next couple of
days as the cyclone moves roughly parallel to the coast of
southwestern Mexico. The mid-level steering ridge over northern
Mexico is forecast to slide eastward later this week, while a
deep-layer trough amplifies over the eastern Pacific and moves
slowly toward the Baja California peninsula. The flow between these
two features should induce a turn toward the north or
north-northeast over the weekend, bringing the center of the system
toward the coast of southwestern or west-central Mexico on Sunday.
Overall, the track guidance is in very good agreement through 72 h,
with larger spread noted by 96 h while the system turns toward the
coast of Mexico. The NHC track forecast lies near the center of the
guidance envelope, generally remaining close to the TVCE aid.

The forecast track brings the system over some of the warmest SSTs
in the eastern Pacific basin during the next couple of days. Also,
the system will be moving within a moist and unstable environment,
and the deep-layer shear is forecast to be less than 10 kt during
this time. Given these favorable atmospheric and oceanic conditions,
the NHC forecast calls for steady to near rapid strengthening during
the next few days. The system is forecast to become a hurricane by
late Friday, with additional strengthening expected thereafter while
it approaches the coast. The NHC forecast generally follows the IVCN
multi-model consensus aid and lies just below HCCA. After moving
inland by 96 h, interaction with the topography of western Mexico
should cause quick weakening and dissipation of the low-level
circulation by 120 h.

Interests along the coasts of southwestern and west-central Mexico
should closely monitor the progress of this system, as watches could
be required for portions of the coastline later tomorrow or tomorrow
night.


FORECAST POSITIONS AND MAX WINDS

INIT 20/0300Z 15.2N 101.3W 30 KT 35 MPH
12H 20/1200Z 15.3N 102.2W 35 KT 40 MPH
24H 21/0000Z 15.6N 103.2W 45 KT 50 MPH
36H 21/1200Z 16.0N 104.1W 55 KT 65 MPH
48H 22/0000Z 16.6N 105.1W 65 KT 75 MPH
60H 22/1200Z 17.6N 105.9W 75 KT 85 MPH
72H 23/0000Z 18.9N 106.3W 90 KT 105 MPH
96H 24/0000Z 22.5N 105.2W 55 KT 65 MPH...INLAND
120H 25/0000Z...DISSIPATED

$$
Forecaster Reinhart

[Sciencerocks]

[Netzero9455]

Possible threat to the Puerto Vallarta area then, I know the crucial aspect will be when it makes the turn to the northwest and then north-northeast, but in this case would a stronger storm theoretically drive itself into the weakness faster and therefore further south or would that make it take a more northerly course, say around where Orlene made landfall?

[ElectricStorm]

Another classic October right-hook into Mexico. I think this has pretty big potential, good chance for a major here IMO

[Yellow Evan]

TXPZ22 KNES 200603
TCSENP

A. 19E (NONAME)

B. 20/0530Z

C. 15.1N

D. 101.0W

E. THREE/GOES-E

F. T1.5/1.5

G. IR/EIR/SWIR

H. REMARKS...3/10 BANDING RESULTS IN A DT OF 1.5. THE MET AND PT
AGREE. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...BERTALAN

[Yellow Evan]

EP, 19, 2022102006, , BEST, 0, 151N, 1013W, 30, 1007, TD, 34, NEQ, 0, 0, 0, 0, 1011, 120, 70, 0, 0, E, 0, , 0, 0, NINETEEN, S, 0, , 0, 0, 0, 0, genesis-num, 033,

[Yellow Evan]

 https://twitter.com/wxpatel/status/1582944498849841153

[cycloneye]

BULLETIN
Tropical Depression Nineteen-E Advisory Number 2
NWS National Hurricane Center Miami FL EP192022
400 AM CDT Thu Oct 20 2022

...DEPRESSION CRAWLING WESTWARD...
...EXPECTED TO STRENGTHEN AND PRODUCE HEAVY RAINS AND FLOODING
ALONG PORTIONS OF THE SOUTHWESTERN AND WEST-CENTRAL COAST OF
MEXICO...


SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...15.1N 101.5W
ABOUT 180 MI...290 KM S OF ZIHUATANEJO MEXICO
ABOUT 325 MI...525 KM SE OF MANZANILLO MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES



Tropical Depression Nineteen-E Discussion Number 2
NWS National Hurricane Center Miami FL EP192022
400 AM CDT Thu Oct 20 2022

The circulation associated with the cyclone does not appear to have
tightened up yet, and the center is estimated to be located between
two primary clusters of deep convection. Dvorak classifications
are T2.5/35 kt from TAFB and T1.5/25 kt from SAB, and the objective
ADT estimate from UW-CIMSS is just below tropical storm intensity.
Therefore, the system remains a depression with maximum winds
estimated to be 30 kt.

TAFB and SAB center fixes suggest the depression isn't moving very
fast. The initial motion is westward, or 275/3 kt, with the system
just beginning to move along the southern edge of a mid-tropospheric
high centered near the mouth of the Gulf of California. This high
is expected to slide eastward across Mexico during the next 3 days,
while a deep-layer area of low pressure moves very little well to
the west of the Baja California peninsula. The cyclone should
slowly recurve around the western periphery of the high, eventually
moving northward near the west-central coast of Mexico by Saturday
night and then accelerating north-northeastward over Mexico on
Sunday. There is a typical amount of spread among the track models
for this forecast, with most of the discrepancies related to how
wide and fast a turn the cyclone makes while recurving around the
high. The NHC official forecast favors a more intense cyclone that
makes a tighter, faster turn, and it lies closest to the solutions
of the GFS, COAMPS-TC, and HCCA consensus aid. This forecast
essentially lies on top of the previous NHC prediction.

An environment of negligible deep-layer shear, very warm ocean
temperatures, and sufficient atmospheric moisture should support
steady strengthening in the coming days. The cyclone's peak
intensity will likely be dictated by exactly how long the system
will be over water before reaching land, and it could also be
modulated by some increase in shear in about 3 days. For
continuity's sake, the NHC intensity forecast is mostly unchanged
from the previous prediction, and it most closely follows the HCCA
intensity solution, which is near the upper end of the guidance
envelope. After the system moves inland, rapid weakening is
expected, and the low-level circulation is forecast to dissipate
over the mountainous terrain of Mexico by early Monday. Global
model fields indicate that the mid-level remnants will continue
northeastward across northern Mexico on Monday.


Key Messages:

1. The depression is forecast to become a hurricane before it passes
near or over the west-central coast of Mexico late Saturday and
Sunday, accompanied by strong winds and a potentially dangerous
storm surge. Interests along the coast of southwestern and
west-central Mexico should closely monitor the progress of this
system, and hurricane or tropical storm watches could be required
for portions of this coastline later today.

2. Heavy rainfall could lead to flash flooding and possible
landslides in areas of rugged terrain over coastal southwestern
Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT 20/0900Z 15.1N 101.5W 30 KT 35 MPH
12H 20/1800Z 15.3N 102.3W 40 KT 45 MPH
24H 21/0600Z 15.6N 103.3W 50 KT 60 MPH
36H 21/1800Z 16.1N 104.2W 60 KT 70 MPH
48H 22/0600Z 16.8N 105.2W 70 KT 80 MPH
60H 22/1800Z 17.9N 106.0W 80 KT 90 MPH
72H 23/0600Z 19.4N 106.2W 90 KT 105 MPH
96H 24/0600Z 23.4N 104.3W 50 KT 60 MPH...INLAND
120H 25/0600Z...DISSIPATED

$$
Forecaster Berg

[cycloneye]

TXPZ22 KNES 201208
TCSENP

A. 19E (NONAME)

B. 20/1130Z

C. 15.8N

D. 101.7W

E. THREE/GOES-E

F. T2.0/2.0

G. IR/EIR/SWIR

H. REMARKS...5/10 BANDING RESULTS IN A 2.5. THE MET IS 1.5 AND THE PT
IS 2.0. THE FT IS BASED ON THE PT DUE TO THE PULSING CONVECTION.

I. ADDL POSITIONS

NIL


...BROWN

[cycloneye]

Roslyn

EP, 19, 2022102012, , BEST, 0, 151N, 1017W, 35, 1006, TS

[Sciencerocks]

[cycloneye]

BULLETIN
Tropical Storm Roslyn Advisory Number 3
NWS National Hurricane Center Miami FL EP192022
1000 AM CDT Thu Oct 20 2022

...DEPRESSION BECOMES TROPICAL STORM ROSLYN...
...EXPECTED TO STRENGTHEN MORE AND PRODUCE HEAVY RAINS AND FLOODING
ALONG PORTIONS OF THE SOUTHWESTERN AND WEST-CENTRAL COAST OF
MEXICO...


SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.2N 102.0W
ABOUT 175 MI...280 KM S OF ZIHUATANEJO MEXICO
ABOUT 305 MI...490 KM SSE OF MANZANILLO MEXICO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


Tropical Storm Roslyn Discussion Number 3
NWS National Hurricane Center Miami FL EP192022
1000 AM CDT Thu Oct 20 2022

Convection associated with the cyclone has become a bit better
organized since the last advisory, with a strong cluster having
developed near the center. Various subjective and objective
satellite intensity estimates are now near 35 kt, and based on this
the depression is upgraded to Tropical Storm Roslyn with an initial
intensity of 35 kt. Although the system has strengthened, recent
microwave and conventional satellite imagery suggests that multiple
low-level swirls are present near the center, indicating that the
inner core has not yet tightened up.

The initial motion is now 275/5 kt along the southern edge of a
mid-level ridge to the north and northwest of the storm. In
addition, a deep-layer low pressure area is currently located
southwest of California, and west of the ridge. These features are
forecast to move slowly eastward during the next few days, with the
deep-layer steering flow near Roslyn changing from easterly to
southeasterly to southerly and eventually to southwesterly. This
evolution should cause the storm to recurve between the ridge and
the low and make landfall in western Mexico. The track guidance is
generally in good agreement with this scenario. However, there is
some spread regarding how quickly Roslyn will recurve. The GFS is
on the right side of the guidance envelope with the center passing
near Cabo Corrientes, while the UKMET and ECMWF are farther west.
The new forecast track is similar to the previous forecast and
calls for the center to pass just west of Cabo Corrientes in about
72 h, followed by landfall in mainland Mexico before 96 h. The new
forecast track is near or a little to the east of the consensus
models.

Roslyn is currently over warm sea surface temperatures in a moist
environment with light vertical wind shear. These conditions are
likely to persist for the next 72 h or so, and they should allow
Roslyn to steadily intensify. After 72 h, the intensity forecast
becomes more uncertain due to a forecast increase in shear, the
possibility of dry air entrainment, and the possibility of land
interaction. The new NHC forecast is generally similar to the
previous forecast, although it has a slightly lower peak intensity
before landfall in mainland Mexico due to a downward trend in the
guidance. After landfall, rapid weakening is expected, with the
cyclone dissipating over the mountains of Mexico between 96-120 h.


Key Messages:

1. Roslyn is forecast to become a hurricane before it passes near
or over the west-central coast of Mexico late Saturday and Sunday,
accompanied by strong winds and a potentially dangerous storm surge.
Interests along the coast of southwestern and west-central Mexico
should closely monitor the progress of this system, and hurricane
or tropical storm watches could be required for portions of this
coastline later today.

2. Heavy rainfall from Roslyn could lead to flash flooding and
possible landslides in areas of rugged terrain over coastal
southwestern Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT 20/1500Z 15.2N 102.0W 35 KT 40 MPH
12H 21/0000Z 15.4N 102.8W 45 KT 50 MPH
24H 21/1200Z 15.7N 103.7W 55 KT 65 MPH
36H 22/0000Z 16.3N 104.6W 65 KT 75 MPH
48H 22/1200Z 17.2N 105.5W 75 KT 85 MPH
60H 23/0000Z 18.6N 106.0W 80 KT 90 MPH
72H 23/1200Z 20.3N 105.9W 85 KT 100 MPH
96H 24/1200Z 24.0N 104.0W 35 KT 40 MPH...INLAND
120H 25/1200Z...DISSIPATED

$$
Forecaster Beven

[Yellow Evan]

Much better.

[zzzh]

I see a partially exposed center.