EPAC: FLOSSIE - Post-Tropical - Discussion

[cycloneye]

Possible mission for Monday

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY: POSSIBLE MISSION INTO
SUSPECT AREA EP95 NEAR 16.5N 102.5W FOR 30/1800Z.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat Jun 28 2025

For the eastern and central North Pacific east of 180 longitude:

1. Offshore of Southern Mexico (EP95):
Showers and thunderstorms associated with a broad area of low
pressure located a few hundred miles south-southwest of the Gulf of
Tehuantepec continue to show signs of organization. Environmental
conditions appear conducive for development, and a tropical
depression is expected to form during the next day or so while the
system moves slowly west-northwestward off the coast of southern
Mexico. Potential Tropical Cyclone advisories could be initiated
later today. For additional information, including gale warnings,
please see High Seas Forecasts issued by the National Weather
Service. Regardless of development, locally heavy rainfall is
expected over portions of Central America and southeastern Mexico
through the weekend.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 7 days...high...90 percent.

[Kingarabian]

Would classify it now

[cycloneye]

EP, 95, 2025062818, , BEST, 0, 134N, 972W, 25, 1009, DB

[cycloneye]

Josh again.

 https://x.com/iCyclone/status/1939037948734795928

[cycloneye]

Is maturing fast to be a formidable TC.

[Astromanía]

For now, I think it could reach cat 2, possibly cat 3

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sat Jun 28 2025

For the eastern and central North Pacific east of 180 longitude:

1. Offshore of Southern Mexico (EP95):
Showers and thunderstorms associated with a broad area of low
pressure located a few hundred miles southwest of the Gulf of
Tehuantepec continue to become better organized. Although the
system does not yet appear to have a well-defined circulation,
further development is expected and a tropical depression or
tropical storm will likely form tonight or on Sunday while the
system moves slowly west-northwestward off the coast of southern
Mexico. Interests in southeastern Mexico should monitor the
progress of this system. Regardless of development, locally heavy
rainfall is expected over portions of Central America and
southeastern Mexico through the weekend. For additional
information, including gale warnings, please see High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 7 days...high...90 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 Roberts

[cycloneye]

The models at 00z have the possibbility of RI.

[cycloneye]

TXPZ28 KNES 290007
TCSENP

A. TROPICAL DISTURBANCE (95E)

B. 29/0000Z

C. 13.4N

D. 98.1W

E. FIVE/GOES-E

F. T1.5/1.5

G. IR/EIR/VIS

H. REMARKS...3/10 BANDING RESULTS IN A DT OF 1.5. PT AGREES WHILE THE
MET IS 1.0. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...TURK

[Yellow Evan]

Good to go.

[Yellow Evan]

Offshore of Southern Mexico (EP95):
Showers and thunderstorms associated with a low pressure system
located a few hundred miles south of southern Mexico have become
much better organized over the past several hours. If current
trends continue, a tropical depression will very likely form early
Sunday while the system moves slowly west-northwestward off the
coast of southern Mexico. Interests in southern Mexico should
monitor the progress of this system. Locally heavy rainfall is
expected along portions of the Pacific coast of southern Mexico
during the next few days. For additional information, including
gale warnings, please see High Seas Forecasts issued by the National
Weather Service.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 7 days...high...near 100 percent.

[cycloneye]

Tropical Depression Six-E Discussion Number 1
NWS National Hurricane Center Miami FL EP062025
300 AM CST Sun Jun 29 2025

The convection associated with the area of low pressure located
south of southern Mexico has become much better organized over the
past 12 hours. Additionally, a 29/0328 UTC ASCAT-C pass showed a
well-defined, closed low-level circulation with maximum winds around
25 kt. The latest subjective Dvorak current intensity estimates
from TAFB and SAB are T-2.5 and T-2.0, respectively. The
disturbance is upgraded to a tropical depression based on the
development of organized convection and a well-defined center.

The aforementioned ASCAT pass shows that Tropical Depression Six-E
has a large RMW. However, the cyclone is located within a favorable
environment with warm SSTs, a moist mid-level troposphere and low to
moderate vertical wind shear. The depression is forecast to remain
in these favorable conditions for another 3 to 4 days as it
parallels the coast of Mexico. Due to the large RMW, only slow
strengthening is forecast for the first 24 h. The system is
expected to strengthen more quickly once it establishes a stronger
convective core, and rapid intensification appears likely to occur
by Tuesday. The NHC intensity forecast is at the high end of the
intensity guidance, especially at 60-72 h, and calls for the
system to become a significant hurricane. By 96 h, the cyclone
should reach cooler water, and rapid weakening is likely in 4 to 5
days, with the system likely becoming a remnant low around day 5.

The current motion of the depression is estimated to be westward, or
270/10 kt. The cyclone is forecast to generally move in a
direction between west-northwest and northwest for the next few
days, toward a weakness in the subtropical ridge, and the model
guidance is in good agreement on this general scenario. The NHC
forecast is down the middle of the guidance envelope, close to the
TVCE consensus.

Residents of Mexico should stay updated on the latest forecast. A
track even a little to the right of the official forecast would
bring more significant impacts to the coast of southwestern Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 13.0N 99.5W 25 KT 30 MPH
12H 29/1800Z 13.4N 100.3W 30 KT 35 MPH
24H 30/0600Z 14.5N 101.5W 35 KT 40 MPH
36H 30/1800Z 15.7N 103.0W 45 KT 50 MPH
48H 01/0600Z 16.8N 104.6W 60 KT 70 MPH
60H 01/1800Z 17.8N 106.2W 75 KT 85 MPH
72H 02/0600Z 18.8N 107.5W 85 KT 100 MPH
96H 03/0600Z 20.9N 109.9W 65 KT 75 MPH
120H 04/0600Z 22.6N 112.1W 40 KT 45 MPH...POST-TROPICAL

$$
Forecaster Hagen

[cycloneye]

BULLETIN
Tropical Depression Six-E Intermediate Advisory Number 1A
NWS National Hurricane Center Miami FL EP062025
600 AM CST Sun Jun 29 2025

...DEPRESSION BECOMING BETTER ORGANIZED...


SUMMARY OF 600 AM CST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...13.2N 99.7W
ABOUT 255 MI...410 KM S OF ACAPULCO MEXICO
ABOUT 500 MI...810 KM SE OF MANZANILLO MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES

[cycloneye]

[cycloneye]

Let's say hello to TS Flossie

EP, 06, 2025062912, , BEST, 0, 132N, 997W, 35, 1005, TS

https://ftp.nhc.noaa.gov/atcf/btk/bep062025.dat

[cycloneye]

Models have the RI phase.

[cycloneye]

First visible frames show the center under the convection.

[Sciencerocks]

[Sciencerocks]

Tropical Storm Flossie Discussion Number 2
NWS National Hurricane Center Miami FL EP062025
900 AM CST Sun Jun 29 2025

Convection has continued to become better organized this morning,
with curved banding to the north of the low-level center. Recent
infrared satellite imagery depicts that convection is bursting near
the low-level center with cold cloud tops near -80C. The latest
subjective Dvorak intensity estimates were T2.5, from both TAFB and
SAB. Using these estimates and the recent satellite trends, the
intensity is raised to 35 kt for this advisory. Thus, the sixth
named system in the eastern Pacific, Tropical Storm Flossie.

Flossie is located within a favorable environment for strengthening
with warm SSTs near 30C, moist mid-levels and low to moderate wind
shear. As the system continues to become better organized, the
latest NHC forecast now depicts steady strengthening, with the storm
becoming a hurricane in about 36 h. While not explicitly forecast,
there are some above normal SHIPS rapid intensification (RI)
probabilities and there is potential for RI, which will have to be
monitored in subsequent forecasts. The NHC intensity forecast
remains near the higher end of the guidance envelope near the latest
HCCA corrected consensus aids.

The current motion is estimated to be westward around 280/8 kt,
although as the inner core continues to develop there could be some
short-term track adjustments. The storm is forecast to begin to move
west-northwestward later today then northwestward around the western
periphery of a subtropical ridge. The latest track forecast is
nudged slightly to the right, in between the simple consensus HCCA
corrected consensus.

Residents of Mexico should stay updated on the latest forecast. A
track even a little more to the right of the official forecast could
bring more significant impacts to the coast of southwestern Mexico.

KEY MESSAGES:

1. The outer bands of Tropical Storm Flossie may bring locally heavy
rainfall to the Mexican states of Oaxaca, Guerrero, Michoacán,
Colima and Jalisco through early next week. Life-threatening
flooding and mudslides are possible, particularly in areas of steep
terrain.

2. A tropical storm watch is in effect for southwestern Mexico, and
tropical storm warnings could be required later today or tonight for
a portion of the coast of southern Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 13.4N 99.9W 35 KT 40 MPH
12H 30/0000Z 14.1N 100.7W 45 KT 50 MPH
24H 30/1200Z 15.2N 102.1W 55 KT 65 MPH
36H 01/0000Z 16.3N 103.7W 65 KT 75 MPH
48H 01/1200Z 17.5N 105.4W 75 KT 85 MPH
60H 02/0000Z 18.7N 107.0W 80 KT 90 MPH
72H 02/1200Z 19.8N 108.4W 75 KT 85 MPH
96H 03/1200Z 21.7N 110.4W 55 KT 65 MPH
120H 04/1200Z 23.9N 112.8W 30 KT 35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Kelly