EPAC: FLOSSIE - Post-Tropical - Discussion

[Yellow Evan]

After an earlier dry air intrusion, eye is quickly warming. Some convection remains stuck on the eastern semicircle, though.

[Yellow Evan]

TXPZ28 KNES 020025
TCSENP

A. 06E (FLOSSIE)

B. 02/0000Z

C. 17.9N

D. 107.1W

E. ONE/GOES-W

F. T5.0/5.0

G. IR/EIR/VIS

H. REMARKS...OW EYE SURROUNDED BY LG RING AND EMBEDDED IN LG YIELDS A
DT OF 5.0. THE MET AND PT ARE 5.0. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL

[cycloneye]

100 kts

EP, 06, 2025070200, , BEST, 0, 179N, 1071W, 100, 962, HU

[Sciencerocks]

[ljmac75]

Wow, 2/3rds of the hurricanes this year have become majors. Fine looking storm for this time of year.

[cycloneye]

BULLETIN
Hurricane Flossie Advisory Number 12
NWS National Hurricane Center Miami FL EP062025
800 PM MST Tue Jul 01 2025

...MAJOR HURRICANE FLOSSIE BRINGING GUSTY WINDS AND RAIN TO THE
SOUTHWESTERN COAST OF MEXICO...


SUMMARY OF 800 PM MST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...18.2N 107.4W
ABOUT 210 MI...340 KM WSW OF MANZANILLO MEXICO
ABOUT 365 MI...585 KM SSE OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...962 MB...28.41 INCHES




Hurricane Flossie Discussion Number 12
NWS National Hurricane Center Miami FL EP062025
800 PM MST Tue Jul 01 2025

After briefly filling, the ragged eye of Flossie has reappeared on
geostationary satellite imagery. An SSMIS microwave satellite image
from 0133 UTC showed that the northern eyewall was slightly eroded.
Since then, infrared satellite observations have shown continuous
deep convective bursts in the northeastern quadrant. Objective and
subjective satellite intensity estimates range between 90 to 107
kts. The initial intensity is nudged up to 100 kt based on a blend
of these estimates.

Flossie has about a 12-24 hour window to strengthen in conducive
environmental conditions. Thereafter, global models suggest drier
air and moderate vertical wind sheer could beginning disrupting the
circulation on Wednesday. These conditions should coincide with
the storm crossing the 26 degree isotherm and moving over cooler
waters which should hasten weakening. Flossie is now forecast to
become a post-tropical cyclone in 48 h.

The hurricane is moving west-northwestward at 8 kt. The track
forecast reasoning has not changed. Flossie should continue moving
west-northwestward or northwestward toward a weakness in the
subtropical ridge for the next few days. As the system becomes more
shallow, it should gradually turn westward in the low-level flow.
Only minor changes have been made to the latest official forecast.


KEY MESSAGES:

1. Outer bands of Hurricane Flossie continue to bring locally heavy
rainfall to coastal portions of the Mexican states of Michoacán,
Colima, and Jalisco into Wednesday. Localized flash flooding is
possible.

2. Tropical storm conditions are expected in portions of the
tropical storm warning area in southwestern Mexico for the next few
hours.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0300Z 18.2N 107.4W 100 KT 115 MPH
12H 02/1200Z 18.9N 108.5W 110 KT 125 MPH
24H 03/0000Z 19.8N 109.9W 85 KT 100 MPH
36H 03/1200Z 20.6N 111.1W 70 KT 80 MPH
48H 04/0000Z 21.5N 112.3W 50 KT 60 MPH...POST-TROPICAL
60H 04/1200Z 22.5N 113.7W 40 KT 45 MPH...POST-TROPICAL
72H 05/0000Z 23.3N 115.1W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 06/0000Z 24.0N 118.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 07/0000Z...DISSIPATED

$$
Forecaster Bucci

[HurricaneRyan]

I assume not as much Infared stuff now to view the storm?

[Yellow Evan]

Multiple dry air intrusions have set Flossie back the last several hours. This vortex doesn't seem particularly resilient.

[cycloneye]

BULLETIN
Hurricane Flossie Advisory Number 13
NWS National Hurricane Center Miami FL EP062025
200 AM MST Wed Jul 02 2025

...TROPICAL STORM WATCHES DISCONTINUED FOR ALL OF SOUTHWESTERN
MEXICO...


SUMMARY OF 200 AM MST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...18.6N 108.3W
ABOUT 315 MI...505 KM SSE OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...962 MB...28.41 INCHES




Hurricane Flossie Discussion Number 13
NWS National Hurricane Center Miami FL EP062025
200 AM MST Wed Jul 02 2025

Flossie remains an impressive hurricane early this morning, although
the well-defined eye evident earlier tonight has become less
distinct and somewhat cloud filled in recent satellite images. The
latest subjective Dvorak intensity estimates were T5.5/102 knots
from TAFB and T5.0/90 knots from SAB. Meanwhile, the objective
intensity estimates ranged from 96 to 107 knots at 06z. Based on a
blend of these data, the initial intensity will be held at 100 knots
for this advisory.

Flossie is heading toward the west-northwest or 300/9 knots. This
general motion is expected to continue during the next several days
as the cyclone is steered into a weakness in the mid-level ridge to
the northwest of the system. A turn more to the west is expected
beyond 48 hours as the increasingly shallow system becomes steered
by the low-level trade wind flow. The track forecast has been
shifted slightly to the left of the previous advisory to align with
the latest consensus guidance trends, and closely follows a blend of
the latest GDMI, FSSE and TVCE consensus aids.

The window for additional strengthening appears to be closing
quickly, as Flossie begins to move over slightly less conducive
waters for intensification with sea surface temperatures now around
27C. Wind shear remains light and mid-level moisture remains high
during the next 12 hours, so with the system remaining over
adequately warm water, the intensity should change little. Flossie
will move over much cooler water between 12 and 24 hours, and into a
drier mid-level environment. This should result in rather rapid
weakening of the system, with Flossie expected to become a
post-tropical low by 48 hours, with dissipation following by 96
hours. The intensity forecast has been adjusted to show a bit faster
weakening of the system which is in line with the latest intensity
consensus aids.


KEY MESSAGES:

1. Outer bands of Hurricane Flossie continue to bring locally heavy
rainfall to coastal portions of the Mexican states of Michoacán,
Colima, and Jalisco into Wednesday. Localized flash flooding is
possible.

2. Large swells generated by Flossie will cause life-threatening
surf and rip current conditions along portions of the coast of
southwestern Mexico, and the Baja California peninsula during the
next few days.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0900Z 18.6N 108.3W 100 KT 115 MPH
12H 02/1800Z 19.3N 109.4W 95 KT 110 MPH
24H 03/0600Z 20.2N 110.9W 75 KT 85 MPH
36H 03/1800Z 21.0N 112.3W 55 KT 65 MPH
48H 04/0600Z 22.1N 113.9W 40 KT 45 MPH...POST-TROPICAL
60H 04/1800Z 23.0N 115.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 05/0600Z 23.7N 117.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 06/0600Z...DISSIPATED

$$
Forecaster Jelsema

[cycloneye]

The eye is no longer seen and is downhill from now in a fast way as it moves thru colder waters.

[Yellow Evan]

Not the evolution I expected these last 18 hours. Despite fairly low wind shear that has supported stronger systems in the past, IR evolution has mirrored that of a titled system. Probably peaked around 21z looking back at it.

[cycloneye]

BULLETIN
Hurricane Flossie Advisory Number 14
NWS National Hurricane Center Miami FL EP062025
800 AM MST Wed Jul 02 2025

...FLOSSIE MOVING WEST-NORTHWESTWARD...


SUMMARY OF 800 AM MST...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...19.0N 109.0W
ABOUT 275 MI...445 KM SSE OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...967 MB...28.56 INCHES



Hurricane Flossie Discussion Number 14
NWS National Hurricane Center Miami FL EP062025
800 AM MST Wed Jul 02 2025

Satellite imagery shows that the inner core of Flossie has started
to degrade this morning, and the eye has become more ragged and
cloud filled. An AMSR2 microwave pass around 0916 UTC shows that
the northern eyewall has started to deteriorate, and is open on the
northern side. This suggest a weakening trend has begun, and Flossie
has likely reached peak intensity. While the system has peaked, deep
cold convection continues to wrap around the southern and eastern
side of the system. Satellite intensity estimates range from 90-100
kt. Given the latest satellite trends and using a blend of the
estimates, the initial intensity is set to 95 kt for this advisory.

Flossie continues to move toward the west-northwest or 300/9 knots.
This general motion is expected to continue throughout the remainder
of the forecast period, towards a weakness in the mid-level ridge.
The latest NHC track forecast was nudged slightly to the right of
the previous, and lies near the HCCA corrected consensus.

A steady to rapid weakening trend is expected to begin today. Along
the forecast track, Flossie will continue to move into cooler sea
surface temperatures and drier mid-level air. Thus, the NHC
intensity forecast shows a little quicker weakening trend compared
to the previous, and lies near the simple intensity consensus.
Flossie expected to become a post-tropical low by 36 hours, with
dissipation following by 96 hours.


FORECAST POSITIONS AND MAX WINDS

INIT 02/1500Z 19.0N 109.0W 95 KT 110 MPH
12H 03/0000Z 19.7N 110.1W 80 KT 90 MPH
24H 03/1200Z 20.6N 111.5W 60 KT 70 MPH
36H 04/0000Z 21.7N 113.0W 45 KT 50 MPH...POST-TROPICAL
48H 04/1200Z 22.7N 114.6W 35 KT 40 MPH...POST-TROPICAL
60H 05/0000Z 23.7N 116.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 05/1200Z 24.4N 118.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 06/1200Z...DISSIPATED

$$
Forecaster Kelly

[cycloneye]

BULLETIN
Hurricane Flossie Advisory Number 15
NWS National Hurricane Center Miami FL EP062025
200 PM MST Wed Jul 02 2025

...FLOSSIE WEAKENS AS IT PASSES SOUTH OF BAJA CALIFORNIA SUR...


SUMMARY OF 200 PM MST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...19.5N 109.8W
ABOUT 235 MI...380 KM S OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...100 MPH...155 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...974 MB...28.77 INCHES



Hurricane Flossie Discussion Number 15
NWS National Hurricane Center Miami FL EP062025
200 PM MST Wed Jul 02 2025

Flossie is feeling the effects of decreasing sea surface
temperatures, with the associated convection waning and becoming
asymmetric. The latest subjective satellite intensity estimates
indicate weakening, and recent objective satellite estimates are in
the 80-90 kt range. Based on this, the initial intensity is
decreased to a possibly generous 85 kt. The initial wind radii have
been revised based on a 1638Z ASCAT overpass.

The initial motion is 305/8 kt. Flossie is moving toward a break
in the subtropical ridge caused by a mid- to upper-level trough
over California and the adjacent Pacific. A general northwestward
motion should continue for the next couple of days. After that,
Flossie should lose vertical depth as it weakens, with the remnant
low being steered more toward the west-northwest by the mean
low-level flow. The new forecast track is almost identical to the
previous track and lies near the various consensus models.

Steady to rapid weakening is forecast to continue as Flossie moves
over cooler water and into a drier air mass. The cyclone is
predicted to become post-tropical in about 36 h as it stops
producing convection, and it is expected to decay to a remnant low
thereafter. The system is forecast to dissipate completely by
96 h, and this could happen earlier than currently forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 02/2100Z 19.5N 109.8W 85 KT 100 MPH
12H 03/0600Z 20.1N 110.8W 70 KT 80 MPH
24H 03/1800Z 21.1N 112.3W 55 KT 65 MPH
36H 04/0600Z 22.1N 113.8W 40 KT 45 MPH...POST-TROPICAL
48H 04/1800Z 23.1N 115.4W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 05/0600Z 24.0N 117.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 05/1800Z 24.7N 118.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 06/1800Z...DISSIPATED

$$
Forecaster Beven

[cycloneye]

BULLETIN
Hurricane Flossie Advisory Number 16
NWS National Hurricane Center Miami FL EP062025
800 PM MST Wed Jul 02 2025

...FLOSSIE RAPIDLY WEAKENING AS IT PASSES SOUTH OF BAJA CALIFORNIA
SUR...


SUMMARY OF 800 PM MST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...19.8N 110.2W
ABOUT 215 MI...345 KM S OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...986 MB...29.12 INCHES


Hurricane Flossie Discussion Number 16
NWS National Hurricane Center Miami FL EP062025
800 PM MST Wed Jul 02 2025

Flossie is rapidly weakening, with deep convection now confined to
the western and southwestern quadrants of the circulation and the
low-level center almost fully exposed. This trend is supported by
recent Dvorak classifications, with current intensity estimates from
TAFB at 4.5/77 kt and SAB at 4.0/65 kt. Objective satellite
intensity estimates range between 56 and 72 kt. A blend of these
data supports lowering the initial intensity to 65 kt.

The initial motion is 305/7 kt. Flossie is moving along the
southwestern periphery of a subtropical ridge, with a weakness in
the ridge induced by a mid- to upper-level trough over the Baja
California region. A continued northwestward motion is expected
during the next couple of days, followed by a gradual turn toward
the west-northwest as the system decouples vertically. The latest
forecast track remains very close to the previous advisory and is
well-supported by the consensus aids.

Rapid weakening is expected to continue as Flossie moves over
progressively cooler waters and into a more stable and drier
environment. The cyclone is forecast to become post-tropical by late
Thursday, or within the next 24 hours, and degenerate into a remnant
low shortly thereafter. The system is expected to dissipate by late
Saturday, around 72 hours from now.

FORECAST POSITIONS AND MAX WINDS

INIT 03/0300Z 19.8N 110.2W 65 KT 75 MPH
12H 03/1200Z 20.4N 111.3W 55 KT 65 MPH
24H 04/0000Z 21.4N 112.7W 40 KT 45 MPH...POST-TROPICAL
36H 04/1200Z 22.6N 114.2W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 05/0000Z 23.6N 115.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 05/1200Z 24.1N 117.4W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 06/0000Z...DISSIPATED

$$
Forecaster Gibbs/Jelsema/Blake

[cycloneye]

BULLETIN
Tropical Storm Flossie Advisory Number 17
NWS National Hurricane Center Miami FL EP062025
200 AM MST Thu Jul 03 2025

...FLOSSIE WEAKENS INTO A TROPICAL STORM...


SUMMARY OF 200 AM MST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...20.1N 111.0W
ABOUT 205 MI...330 KM SSW OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...994 MB...29.36 INCHES



Tropical Storm Flossie Discussion Number 17
NWS National Hurricane Center Miami FL EP062025
200 AM MST Thu Jul 03 2025

Flossie continues to rapidly weaken, with a recent ASCAT pass
indicating instrument derived winds of only 40 to 45 kt north of
the center. The cyclone’s structure has further degraded, with deep
convection absent and the low-level circulation now fully exposed.
Both subjective and objective satellite current intensity estimates
reflect this weakening trend, and the initial intensity has been
lowered to 50 kt based on a blend of these data.

The initial motion is 300/8 kt. Flossie continues to move along the
southwestern edge of a mid-level ridge situated over northern
Mexico. This general motion is expected to persist for the next
couple of days. The updated forecast track is nearly unchanged from
the previous advisory and remains close to the consensus guidance.

Continued weakening is anticipated as the system moves over cooler
waters and remains embedded in a dry and stable environment. With no
deep convection, Flossie is forecast to become a post-tropical
remnant low later today, with dissipation expected by 60 hours, if
not sooner.


FORECAST POSITIONS AND MAX WINDS

INIT 03/0900Z 20.1N 111.0W 50 KT 60 MPH
12H 03/1800Z 20.9N 112.0W 40 KT 45 MPH
24H 04/0600Z 22.1N 113.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 04/1800Z 23.2N 115.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 05/0600Z 24.0N 116.9W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 05/1800Z...DISSIPATED

$$
Forecaster Gibbs/Jelsema/Papin

[cycloneye]

BULLETIN
Tropical Storm Flossie Advisory Number 18
NWS National Hurricane Center Miami FL EP062025
800 AM MST Thu Jul 03 2025

...FLOSSIE WEAKENING RAPIDLY OVER COOL WATER...


SUMMARY OF 800 AM MST...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...20.6N 111.7W
ABOUT 195 MI...315 KM SW OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES


Tropical Storm Flossie Discussion Number 18
NWS National Hurricane Center Miami FL EP062025
800 AM MST Thu Jul 03 2025

Flossie is now a swirl of low- to mid-level clouds with no
associated convection as it moves over colder sea surface
temperatures to the southwest of Baja California Sur. The initial
intensity is decreased to a somewhat uncertain 40 kt in agreement
with the latest subjective and objective satellite intensity
estimates. Flossie should continue to steadily weaken, with the
cyclone expected to become a post-tropical low later today and a
remnant low tonight. The system should dissipate completely by 60 h.

The initial motion is 300/9. A generally northwestward to
west-northwestward should continue to the next 36 h or so, followed
by a gradual bend more toward the west-northwest. The new track
forecast is close to the previous forecast and the consensus models.


FORECAST POSITIONS AND MAX WINDS

INIT 03/1500Z 20.6N 111.7W 40 KT 45 MPH
12H 04/0000Z 21.4N 112.9W 35 KT 40 MPH...POST-TROPICAL
24H 04/1200Z 22.6N 114.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 05/0000Z 23.6N 116.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 05/1200Z 24.3N 117.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 06/0000Z...DISSIPATED

$$
Forecaster Beven

[cycloneye]

BULLETIN
Post-Tropical Cyclone Flossie Advisory Number 19
NWS National Hurricane Center Miami FL EP062025
200 PM MST Thu Jul 03 2025

...FLOSSIE NOW A POST-TROPICAL CYCLONE...
...THIS IS THE LAST NHC ADVISORY...


SUMMARY OF 200 PM MST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...21.2N 112.4W
ABOUT 200 MI...320 KM SW OF CABO SAN LUCAS MEXICO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES