EPAC: PAMELA - Remnants

[cycloneye]

Showers and thunderstorms associated with a broad area of low
pressure located a few hundred miles south of the southern coast of
Mexico have been increasing in coverage today but remain
disorganized. Environmental conditions are forecast to be conducive
for additional development, and a tropical depression or tropical
storm is expected to form within the next day or two while the
system moves west-northwestward at about 15 mph south of the coast
of Mexico. Additional information on this system can be found in
High Seas Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[aspen]

Looking at the recent HWRF runs, I think anything more than a low-end Cat 4 is becoming even less likely, because they’re forecasting EWRCs/melds and inner core dynamics that’ll keep Pamela at bay for a while. While the HWRF shows intensification until landfall, I doubt that’ll happen due to the jet.

[aspen]

Lots of rocket fuel in Pamela's path - assuming it will take advantage of it, which I'm doubtful it will.

[Yellow Evan]

Looking at the recent HWRF runs, I think anything more than a low-end Cat 4 is becoming even less likely, because they’re forecasting EWRCs/melds and inner core dynamics that’ll keep Pamela at bay for a while. While the HWRF shows intensification until landfall, I doubt that’ll happen due to the jet.

Why are we trusting HWRF to forecast inner core dynamics?

[aspen]

Looking at the recent HWRF runs, I think anything more than a low-end Cat 4 is becoming even less likely, because they’re forecasting EWRCs/melds and inner core dynamics that’ll keep Pamela at bay for a while. While the HWRF shows intensification until landfall, I doubt that’ll happen due to the jet.

Why are we trusting HWRF to forecast inner core dynamics?

It has done decently with inner core dynamics and structures, like showing Larry’s massive eye, Sam’s multiple eyewall melds/EWRCs following its initial peak, and Eta’s pinhole structure just to name a few in the last year.

[Sciencerocks]

[Yellow Evan]

12z GFS and ECMWF. Better agreement on track though history says 12z GFS will win out.

[Yellow Evan]

Looking at the recent HWRF runs, I think anything more than a low-end Cat 4 is becoming even less likely, because they’re forecasting EWRCs/melds and inner core dynamics that’ll keep Pamela at bay for a while. While the HWRF shows intensification until landfall, I doubt that’ll happen due to the jet.

Why are we trusting HWRF to forecast inner core dynamics?

It has done decently with inner core dynamics and structures, like showing Larry’s massive eye, Sam’s multiple eyewall melds/EWRCs following its initial peak, and Eta’s pinhole structure just to name a few in the last year.

The latter two had Recon data infested and given how common large eyes are simulated on models in general, not sure how much credit it deserves for nailing Larry’s massive eye. This certainly isn’t ground to downplay the storm when conditions are super favorable once this rounds the ridge.

[Yellow Evan]

18z GFS just as strong despite further west initialization. Track also more west with Mazatlan likely to be in the bullseye.

[aspen]

Why are we trusting HWRF to forecast inner core dynamics?

It has done decently with inner core dynamics and structures, like showing Larry’s massive eye, Sam’s multiple eyewall melds/EWRCs following its initial peak, and Eta’s pinhole structure just to name a few in the last year.

The latter two had Recon data infested and given how common large eyes are simulated on models in general, not sure how much credit it deserves for nailing Larry’s massive eye. This certainly isn’t ground to downplay the storm when conditions are super favorable once this rounds the ridge.

I will gladly eat a serving of crow if Pamela does indeed bomb out in the last 24 hours before landfall and isn’t weakened by its orientation with the jet streak changing. I’m hoping it doesn’t realize its full potential in that area because its full potential would be a sub-875mb Cat 5.

[Yellow Evan]

It has done decently with inner core dynamics and structures, like showing Larry’s massive eye, Sam’s multiple eyewall melds/EWRCs following its initial peak, and Eta’s pinhole structure just to name a few in the last year.

The latter two had Recon data infested and given how common large eyes are simulated on models in general, not sure how much credit it deserves for nailing Larry’s massive eye. This certainly isn’t ground to downplay the storm when conditions are super favorable once this rounds the ridge.

I will gladly eat a serving of crow if Pamela does indeed bomb out in the last 24 hours before landfall and isn’t weakened by its orientation with the jet streak changing. I’m hoping it doesn’t realize its full potential in that area because its full potential would be a sub-875mb Cat 5.

I worded that sort of wrong. It’ll probably be unraveling at landfall since recurvature would have been underway by at least 12 hours by then, enough for this to get blasted by southwesterly shear. Prior to that is when this has the potential to bomb out when the system is rounding the ridge and starting to interact with the jet streak.

[Yellow Evan]

12-18 hours away from classifiable.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sat Oct 9 2021

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

1. Showers and thunderstorms associated with a broad area of low
pressure located a few hundred miles south of the southern coast of
Mexico are gradually becoming better organized. Environmental
conditions are conducive for additional development, and a tropical
depression or tropical storm is expected to form within the next
day or so while the system moves west-northwestward at about 15 mph
south of the coast of Mexico. 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...90 percent.
* Formation chance through 5 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 Blake

[aspen]

18z GFS has a 10mb drop in just 3 hours, from 977mb to 967mb between 06z and 09z Monday morning.

It reaches 948mb by Monday afternoon and has a pinhole eye, although the HWRF once again attempts an EWRC. This is the fastest intensification shown for Pamela so far.

[Sciencerocks]

[Yellow Evan]

TXPZ29 KNES 100003
TCSENP

A. TROPICAL DISTURBANCE (91E)

B. 09/2330Z

C. 13.7N

D. 101.3W

E. FIVE/GOES-E

F. T1.0/1.0

G. IR/EIR/VIS

H. REMARKS...>2/10 BANDING RESULTS IN A DT OF 1.0. THE MET IS 1.0 BASED
ON THE INITIAL DEVELOPMENT TREND. THE PT AGREES WITH 1.0. FT IS BASED
ON DT.

I. ADDL POSITIONS

NIL


...COVERDALE

[aspen]

The 18z HWRF shows this going pinhole and bombing out at something like 3mb/hr, but it is stopped by an EWRC. Pamela still manages to make a 110-115kt Cat 3/4 landfall, though.

[Yellow Evan]

[Astromanía]

This is looking bad for Mazatlan, that looks like a monster developing

[Yellow Evan]

This setup with that divergence is a lot closer to Willa at landfall than Rick fwiw.