EPAC: ALVIN - Remnant - Discussion

[galaxy401]

This system might bring some rain over in Arizona. At least the moisture associated with it. Have a chance of rain on Sunday and Monday. Bring a nice cooldown in temperatures too as summer begins.

[Hurricane2022]

"Tropical Depression Patricia, 2025"

[cycloneye]

Will they upgrade to tropical storm Alvin on next advisory?

[cycloneye]

Well, here is the answer. Not yet.

BULLETIN
Tropical Depression One-E Advisory Number 2
NWS National Hurricane Center Miami FL EP012025
900 PM CST Wed May 28 2025

...DEPRESSION EXPECTED TO STRENGTHEN INTO A TROPICAL STORM ON
THURSDAY...


SUMMARY OF 900 PM CST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...12.8N 104.9W
ABOUT 770 MI...1240 KM SSE OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES

Tropical Depression One-E Discussion Number 2
NWS National Hurricane Center Miami FL EP012025
900 PM CST Wed May 28 2025

The sprawling depression has shown a modest increase in deep
convection closer to its low-level center in recent satellite
images, but most of the fragmented convective bands remain farther
away in the western semicircle. With little overall structural
change, the latest satellite intensity estimates support holding the
intensity at 30 kt. Overnight ASCAT wind data should provide more
insight into the current intensity and wind field structure.

The estimated initial motion is north-northwestward (335/8 kt), but
a more northwestward motion is expected on Thursday before an
amplifying upper-level disturbance offshore Baja California induces
a northward turn on Friday and into the weekend. The NHC track
forecast has been adjusted slightly to the right this cycle, roughly
in between the latest simple and corrected consensus aids.

The depression should strengthen into a tropical storm during the
next day or so within a weak vertical wind shear environment over
warm waters. The amount of strengthening that occurs will depend on
whether the broad cyclone can develop a tighter inner core before
conditions become less favorable late this week. As the system gains
latitude, strengthening shear and a drier, more stable airmass
will disrupt its convective organization and result in weakening.
The cyclone is forecast to become post-tropical by 72 h and
dissipate before the end of the 5-day forecast period. Based on the
latest track and size forecasts, tropical-storm-force winds are not
expected to impact the coast of mainland Mexico or Baja California.


FORECAST POSITIONS AND MAX WINDS

INIT 29/0300Z 12.8N 104.9W 30 KT 35 MPH
12H 29/1200Z 13.8N 106.0W 40 KT 45 MPH
24H 30/0000Z 15.0N 107.5W 50 KT 60 MPH
36H 30/1200Z 16.4N 108.4W 55 KT 65 MPH
48H 31/0000Z 18.1N 108.6W 50 KT 60 MPH
60H 31/1200Z 19.7N 108.6W 40 KT 45 MPH
72H 01/0000Z 21.3N 108.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 02/0000Z 23.5N 108.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 03/0000Z...DISSIPATED

$$
Forecaster Reinhart

[Sciencerocks]

[cycloneye]

Tropical Depression One-E Discussion Number 3
NWS National Hurricane Center Miami FL EP012025
200 AM MST Thu May 29 2025

The depression has been holding steady overnight. While
thunderstorm activity has increased since the previous advisory,
recent scatterometer data has revealed that the surface winds remain
generally unchanged. The initial intensity is held at 30 kt based
on the ASCAT data, which is also close to the other subjective and
objective satellite estimates.

The initial motion is 330/8 kt. The depression is expected to move
north-northwestward to northwestward for the next day or so. Then
an amplifying upper-level trough offshore Baja California should
turn the system northward on Friday and into the weekend. The NHC
track forecast has shifted slightly to the west, largely because of
the initial position, and it lies between the various consensus
aids.

The window for the cyclone to strengthen is gradually closing. The
depression is still expected to become a tropical storm sometime
later today, though the system only has about 36 hours of conducive
environmental conditions. The NHC peak intensity has been lowered
to 50 kt and is at the top of the intensity forecast guidance
envelope. In a couple of days, the vertical wind shear is forecast
to increase while the cyclone moves over cooler waters and into a
dry and stable air mass. Global models predict the system will lose
its organized convection at this point and the NHC forecast now
shows the system becoming post-tropical in 60 h. Based on the
latest track and size forecasts, tropical-storm-force winds are not
expected to impact the coast of mainland Mexico or Baja California.


FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 13.3N 106.0W 30 KT 35 MPH
12H 29/1800Z 14.4N 107.1W 40 KT 45 MPH
24H 30/0600Z 15.6N 108.3W 50 KT 60 MPH
36H 30/1800Z 17.2N 108.8W 50 KT 60 MPH
48H 31/0600Z 18.8N 109.0W 45 KT 50 MPH
60H 31/1800Z 20.3N 108.9W 35 KT 40 MPH...POST-TROPICAL
72H 01/0600Z 21.8N 108.8W 25 KT 30 MPH...POST-TROPICAL
96H 02/0600Z 24.5N 108.8W 20 KT 25 MPH...POST-TROPICAL
120H 03/0600Z...DISSIPATED

$$
Forecaster Bucci

[Sciencerocks]

[cycloneye]

It finally becomes a TD and everybody clams up?

Agree 100%. If this would have been a hurricane, let alone a major, for sure this thread had been hopping with over 100 posts and over 10 pages.

[TomballEd]

It finally becomes a TD and everybody clams up?

Agree 100%. If this would have been a hurricane, let alone a major, for sure this thread had been hopping with over 100 posts and over 10 pages.

It is more of an October thing but the EPAC tropics can affect Texas with the remnants. I remember the floods (the San Jacinto river scored down to a gasoline and oil pipeline and the river caught fire from the remnants of H. Rosa in 1994. I imagine it could happen early as well as late in the EPAC season.

https://www.google.com/search?q=san+jacinto+river+fire+1994+video&rlz=1C1GCEU_enUS1148US1148&oq=1994+san+jacinto+river+&gs_lcrp=EgZjaHJvbWUqCAgBEAAYFhgeMgYIABBFGDkyCAgBEAAYFhgeMgcIAhAAGO8FMgoIAxAAGIAEGKIEMgoIBBAAGIAEGKIEMgoIBRAAGIAEGKIE0gEIOTgyNGowajeoAgiwAgHxBdYKNGsIPdzT8QXWCjRrCD3c0w&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:1196f556,vid:bWEsgM-c2Vk,st:0

[cycloneye]

Alvin is the first named storm of the Northern Hemisphere.

SUMMARY OF 800 AM MST...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...13.8N 106.3W
ABOUT 670 MI...1080 KM SSE OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES

Tropical Storm Alvin Discussion Number 4
NWS National Hurricane Center Miami FL EP012025
800 AM MST Thu May 29 2025

Tropical Storm Alvin has formed several hundred n mi south of
southwestern Mexico. Satellite imagery shows thunderstorm activity
has increased and has become more organized around the center.
Although the TAFB and SAB Dvorak estimates have been steady at
2.0/30 kt, the objective satellite intensity estimates are higher
and generally between 35 and 45 kt. Based on a consensus of the
data, the initial intensity has been increased to 35 kt for this
advisory.

The initial motion is 315/9 kt. The storm is expected to continue
toward the northwest today, then begin turning toward the
north-northwest tomorrow as it moves around a ridge centered over
central Mexico. By tomorrow night, Alvin will begin moving northward
as it is influenced my a mid-level cut-off low. The NHC track
forecast is generally similar to the previous one.

Alvin should continue to strengthen today, within a favorable
environment of warm sea surface temperatures and low wind shear for
about the next 24 hours. The NHC peak intensity remains at 50 kt,
which is near the high end of the model guidance. Weakening is
expected to begin tomorrow as the storm moves into progressively
higher shear and a drier environment with cooler SSTs. There is high
confidence that the system will weaken to a remnant low before it
nears the Baja California Peninsula.


FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 13.8N 106.3W 35 KT 40 MPH
12H 30/0000Z 14.7N 107.4W 45 KT 50 MPH
24H 30/1200Z 16.1N 108.3W 50 KT 60 MPH
36H 31/0000Z 17.6N 108.7W 45 KT 50 MPH
48H 31/1200Z 19.1N 108.8W 35 KT 40 MPH
60H 01/0000Z 20.7N 108.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 01/1200Z 21.9N 108.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 02/1200Z...DISSIPATED

$$
Forecaster Mora/Cangialosi

[Sciencerocks]

[Kingarabian]

Core is developing based on CIMSS MIMIC imagery.

NRL and FNMOC look to be down for a while.

[LarryWx]

If anyone has a trip planned for the Cabo area the next few days, Alvin will weaken to almost nothing near there. But should be cloudy Fri and clouds with probably some on/off rain Sat ending Sun AM (shouldn’t be heavy anounts) with some sun PM. Mon+ looks nicer.

[Sciencerocks]

[Sciencerocks]

 https://x.com/VortixWx/status/1928154483319558308

[cycloneye]

ADT at 3.0.

[Kingarabian]

CDO has formed and maintained over the last 6 hours, covering the LLC.
This could easily be a high end tropical storm. Repeated hot towers going off.

[cycloneye]

SSD Dvorak at 3.0.

A. 01E (ALVIN)

B. 29/1800Z

C. 14.9N

D. 106.7W

E. THREE/GOES-W

F. T3.0/3.0

G. IR/EIR/VIS

H. REMARKS...9/10 BANDING RESULTS IN A DT OF 3.5. THE MET IS 2.5 AND THE
PT IS 3.0. THE FT IS BASED ON CONSTRAINTS LIMITING CHANGE IN T-NUMBER
TO 1.0 OVER 6 HOURS SINCE 6-HOUR AVERAGE DT OF 3.3 DID NOT JUSTIFY
BREAKING CONSTRAINTS.

I. ADDL POSITIONS

NIL


...LINER

[cycloneye]

18z Best Track up to 45kt.

EP, 01, 2025052918, , BEST, 0, 14.6N, 106.8W, 45, 1002, TS

https://ftp.nhc.noaa.gov/atcf/btk/bep012025.dat

[DorkyMcDorkface]

Solid mid-grade TS. With that being said it kind of floundered and wasted quite a bit of time developing due to how broad the precursor disturbance was, so it probably won't have the time or real estate to make it to hurricane intensity before it reaches a more prohibitive environment in another 12-18 hours or so. GFS was overzealous in spinning it up so rapidly. Euro was far more realistic in this case