2021 EPAC Season

[Ubuntwo]

GFS has been on and off with a tropical wave developing in the eastern Pacific.

[Yellow Evan]

Looks phantom at least at the rate that it shows development. GFS is probably overdoing the vorticity as the wave axis interacts with Central America, leading to rapid TC genesis offshore.

[Kingarabian]

GFS has been on and off with a tropical wave developing in the eastern Pacific.
https://imgur.com/hHkTtQE

Normally would favor WCaribbean development here.

[Yellow Evan]

GFS has been on and off with a tropical wave developing in the eastern Pacific.
https://imgur.com/hHkTtQE

Normally would favor WCaribbean development here.

With all that troughing over the southern US, hard to get anything substantial in the WCaribbean and the wave axis never reaches that high of a latitude anyway.

[Ubuntwo]

:uarrow: Looks phantom at least at the rate that it shows development. GFS is probably overdoing the vorticity as the wave axis interacts with Central America, leading to rapid TC genesis offshore.

0z GFS has slower development with the wave but runs into a better environment later down the road:

[Yellow Evan]

 https://twitter.com/andyhazelton/status/1454131040440758272

[Yellow Evan]

12z GFS.

[aspen]

18z GFS and GEFS ensembles somehow think that a hurricane on November 7th during a La Niña is a perfectly reasonable solution. It’s also around the area where the GFS has failed miserably to predict the impact of shear on systems trying to intensify there (Guillermo, Kevin, and Pamela), so if it does form it probably won’t break 995.

[Yellow Evan]

Even the 18z GFS only brings it down to 991 mbar.

[Kingarabian]

Had some late season systems in -ENSO years.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Mon Nov 1 2021

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

1. An area of low pressure is expected to form later this week, several
hundred miles south of the southwestern coast of Mexico. Some slow
develop of this system is possible thereafter while it moves
westward to west-northwestward at 5 to 10 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

Forecaster Latto

[Yellow Evan]

202
ABPZ20 KNHC 021727
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Tue Nov 2 2021

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

An area of low pressure located inland over Costa Rica is forecast
to move across Central America through tonight, producing locally
heavy rainfall across portions of southern Nicaragua, Costa Rica,
and Panama, which could result in flooding and mudslides. The system
is forecast to emerge over the far eastern Pacific waters on
Wednesday, and some slow development of the system is possible
thereafter while it moves westward at around 10 mph.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...30 percent.

An area of low pressure is expected to form later this week several
hundred miles south of the southwestern coast of Mexico. Some slow
development of this system is possible thereafter while it moves
westward to west-northwestward at 5 to 10 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Latto

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Tue Nov 2 2021

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

1. An elongated area of low pressure located over Costa Rica is
forecast to emerge over the far eastern Pacific waters on Wednesday.
Environmental conditions are expected to be conducive for gradual
development, and a tropical depression could form well south or
southeast of the coast of southeastern Mexico late this week or this
weekend. Regardless of development, the system is expected to
produce locally heavy rainfall across portions of southern
Nicaragua, Costa Rica, and Panama through Wednesday, which could
result in flooding and mudslides.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...50 percent.

2. An area of disturbed weather has formed several hundred miles south
of Acapulco, Mexico. Some slow development of this system is
possible during the next several days while it moves westward to
west-northwestward at 5 to 10 mph well to the south of the southern
coast of Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

Forecaster Brown

[cycloneye]

The replacement satellite of GOES-17 will be up next year.

 https://twitter.com/NOAASatellitePA/status/1458470523726450689

[Yellow Evan]

Pretty forgettable season all in all though given the background state it probably could have been worse. Linda and Felicia were definitely cool though and a record four (IMO five) hurricanes hit Mexico this year.

[Kingarabian]

Could've been another 2010 or something like 2019/2020 considering the La Nina. Instead we got a bunch of Mexico activity, some annular long trackers, and some CPHC drama. Exceeded my expectations.

[Kingarabian]

Hawaii right now:




You can see why systems coming from the east don't do much with those strong upper level westerlies in place, while systems south of the islands can easily dump historic rain.