2021 EPAC Season

[Kingarabian]

I wonder if all this early season activity is going to drain the EPAC of energy for later? It seems like this has happened before and when things shut down, the Atlantic became very active.

The instability/energy to produce storms no matter what some charts are showing, shows that the EPAC has it so far this season. A lot of this favorability is due to the Nino regions warming, resulting in a temporarily +ENSO phase to be in place. The EPAC will lose this favorability once the Nino regions cool and ENSO shifts back to negative in August. This should allow the Atlantic to become active and sustain that activity.

[Kingarabian]

Looks like that western TW wave that may or may not develop, has a disorganized center and its 850mb vort signature is slowly improving.

[Kingarabian]

12z EPS shows a little more support for the first/western wave.


18z GFS continues to show the second wave developing and then absorbing the first disturbance. It's clear though that there will be two distinctive systems

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Tue Jun 22 2021

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

1. A tropical wave is producing disorganized showers and thunderstorms
extending several hundred miles south of the coasts of Guatemala,
El Salvador, and southern Mexico. Environmental conditions appear
conducive for development of this system, and a tropical depression
is expected to form late this week or this weekend while moving
west-northwestward at about 10 mph. This system is expected to be
near the coast of southern or southwestern Mexico by this weekend,
and interests in those areas should monitor its progress.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...90 percent.

Forecaster Berg

[aspen]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Tue Jun 22 2021

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

1. A tropical wave is producing disorganized showers and thunderstorms
extending several hundred miles south of the coasts of Guatemala,
El Salvador, and southern Mexico. Environmental conditions appear
conducive for development of this system, and a tropical depression
is expected to form late this week or this weekend while moving
west-northwestward at about 10 mph. This system is expected to be
near the coast of southern or southwestern Mexico by this weekend,
and interests in those areas should monitor its progress.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...90 percent.

Forecaster Berg

This has got to finally be an invest tonight. I’m surprised it’s taken this long.

[Kingarabian]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Tue Jun 22 2021

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

1. A tropical wave is producing disorganized showers and thunderstorms
extending several hundred miles south of the coasts of Guatemala,
El Salvador, and southern Mexico. Environmental conditions appear
conducive for development of this system, and a tropical depression
is expected to form late this week or this weekend while moving
west-northwestward at about 10 mph. This system is expected to be
near the coast of southern or southwestern Mexico by this weekend,
and interests in those areas should monitor its progress.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...90 percent.

Forecaster Berg

This has got to finally be an invest tonight. I’m surprised it’s taken this long.

It appears invests are sometimes tagged earlier when the NHC has questions or doubts about intensity or track in regards to a disturbance, and they want to see more model runs on it. I think it's pretty straight forward that's it going to develop in the time frame the NHC is giving it.

The system to the west of the 40/90 should be circled or tagged IMO. It's not yet clear what it will do.

[Yellow Evan]

18z GFS brings a hurricane into Michoacan.

[cycloneye]

Invest 95E is up

[Kingarabian]

00z GFS again developing the first TW.

[Stormybajan]

00z Euro again developing the first TW.
https://i.imgur.com/f8fWylx.png

euro? lol

[Kingarabian]

00z Euro again developing the first TW.
https://i.imgur.com/f8fWylx.png

euro? lol

woops lol

[Yellow Evan]

0z GFS develops the westward system but absorbs it into 95E quickly.

[Kingarabian]

18z GFS again briefly develops the western system:




Shows 95E eventually absorbing it. Still can't rule out it developing despite what the models show.

Someone correct me if I'm wrong, but I think in 2018 this type of scenario happened with tropical storm Ileana and hurricane John. Ileana wasn't supposed(modeled) to develop much and was forecast to be absorbed by John. Ileana ended up strengthening to a 65mph TS before weakening due to John's outflow.

[Kingarabian]

 https://twitter.com/webberweather/status/1407758050904088576

[JW-_-]

https://imgur.com/4RScABI


Interesting model thinks in the first week of next month there may be more chances brewing. Alho up to now the systems have been mild. They have been consistently spinning up.

[Yellow Evan]

Nah, the EPAC window closes once +PV anomalies take over after this week through at least mid to late July at best if the EPS weeklies are to be believed.

[Kingarabian]

CFS supports the EPS solution of a theoretical down period for the EPAC beginning in the first week of July. However if we look at past history in the EPAC (based on this CFS hovmoller), the basin has been responding well to intraseasonal passages in forms of -CCKWs, with frequent TCG since May despite modeled out suppressed periods.

[storminabox]

This feels like a much busier season than last year. The overall base state seems more favorable thus far.

[Kingarabian]

00z EPS has a little less support for the western TW but 18z EPS looked better.

[Yellow Evan]

 https://twitter.com/webberweather/status/1408064570346786835




Posting this for the graphic as the real basin that’s shut down here is the EPAC in that pattern.