2021 EPAC Season

[aspen]

https://cdn.discordapp.com/attachments/733552978572869632/872893584230203452/image0.gif

12z GFS has us up to Olaf.

I don’t see how the EPac could be this favored in a -ENSO year, and how the MJO could remain stuck over the EPac with continued sinking motion over the Atlantic.

[Yellow Evan]

12z ECMWF day 10 ends like this.

[captainbarbossa19]

https://cdn.discordapp.com/attachments/733552978572869632/872893584230203452/image0.gif

12z GFS has us up to Olaf.

I don’t see how the EPac could be this favored in a -ENSO year, and how the MJO could remain stuck over the EPac with continued sinking motion over the Atlantic.

Even if the models are right about continued activity, the EPAC is going to eventually run out of juice for storms. This is going to give the Atlantic a strong edge near peak-season.

[Category5Kaiju]

Either the models are very biased toward an El Niño or positive PDO like state, or we’re entering some weird La Niña that also happens to favor activity in the EPAC for mysterious reasons. I think the former is more believable imho

[Kingarabian]

The reasoning behind the models for continued EPAC activity is becoming clear with the time frame coming in. Seems that they're installing a temporarily American standing wave. Despite the hostile indicators in place such as a -ENSO/-PM/-PDO, this standing wave can allow extended EPAC activity. Something sorta similar happened in 2016 and 2017. I'll believe it if we do get four named systems over the next 2 weeks.

[Yellow Evan]

https://cdn.discordapp.com/attachments/733552978572869632/872893584230203452/image0.gif

12z GFS has us up to Olaf.

I don’t see how the EPac could be this favored in a -ENSO year, and how the MJO could remain stuck over the EPac with continued sinking motion over the Atlantic.

Not even an MJO issue really. GFS is just showing an American Standing Wave lol.

[Category5Kaiju]

https://cdn.discordapp.com/attachments/733552978572869632/872893584230203452/image0.gif

12z GFS has us up to Olaf.

I don’t see how the EPac could be this favored in a -ENSO year, and how the MJO could remain stuck over the EPac with continued sinking motion over the Atlantic.

https://cdn.discordapp.com/attachments/733552978572869632/872895631524499466/image0.jpg

Not even an MJO issue really. GFS is just showing an American Standing Wave lol.

It sure loves the 80s

[Yellow Evan]

The reasoning behind the models for continued EPAC activity is becoming clear with the time frame coming in. Seems that they're installing a temporarily American standing wave. Despite the hostile indicators in place such as a -ENSO/-PM/-PDO, this standing wave can allow extended EPAC activity. Something sorta similar happened in 2016 and 2017. I'll believe it if we do get four named systems over the next 2 weeks.

Okay let's back up here because 1) I've implied otherwise earlier in the thread and 2) I've wanted to explain my current point for a few weeks.



This is the 30 day anomaly map. Notice a -VP anomaly from 120-150W, which is probably too far west to have a huge impact at least in a positive light, as well as a +VP anomaly near Central American meaning a weaker monsoon.



1977 (and some other 70s seasons) had a somewhat similar -VP setup in the Pacific to the last 30 days and a +VP setup near Central America.



1982-1994 (excluding 1988-89) all to varying strengths had a -VP near the Americas that enhanced the monsoon. This is what I'm referring to when I mean the American standing wave. Also of note is how dry Africa is.



After 1995-1997, the ASW seemed to retreat as conditions moved towards the Atlantic. A rising cell has been present for most of the years since then over the EPAC but with little activity to show for it, I'm not sure what good it did. This is also not an American standing wave and I'm not really convinced it's helped the basin at all. Maybe it has displaced genesis to the north or northwest, which has limited the potential of long tracked storms at least without a +PMM.



Now here is 2016/17. Similar setup. Perhaps the +PMM allowed the EPAC rising cell to be taking advantage of.

[Kingarabian]

The reasoning behind the models for continued EPAC activity is becoming clear with the time frame coming in. Seems that they're installing a temporarily American standing wave. Despite the hostile indicators in place such as a -ENSO/-PM/-PDO, this standing wave can allow extended EPAC activity. Something sorta similar happened in 2016 and 2017. I'll believe it if we do get four named systems over the next 2 weeks.

Okay let's back up here because 1) I've implied otherwise earlier in the thread and 2) I've wanted to explain my current point for a few weeks.

[url]https://i.imgur.com/swWx0jn.png[url]

This is the 30 day anomaly map. Notice a -VP anomaly from 120-150W, which is probably too far west to have a huge impact at least in a positive light, as well as a +VP anomaly near Central American meaning a weaker monsoon.

[url]https://i.imgur.com/eKXGgMa.png[/rl]

1977 (and some other 70s seasons) had a somewhat similar -VP setup in the Pacific to the last 30 days and a +VP setup near Central America.

[url]https://i.imgur.com/6ld7CHJ.png[/rl]

1982-1994 (excluding 1988-89) all to varying strengths had a -VP near the Americas that enhanced the monsoon. This is what I'm referring to when I mean the American standing wave. Also of note is how dry Africa is.

[url]https://i.imgur.com/WrfXltd.png[url]

After 1995-1997, the ASW seemed to retreat as conditions moved towards the Atlantic. A rising cell has been present for most of the years since then over the EPAC but with little activity to show for it, I'm not sure what good it did. This is also not an American standing wave and I'm not really convinced it's helped the basin at all. Maybe it has displaced genesis to the north or northwest, which has limited the potential of long tracked storms at least without a +PMM.

[url]https://i.imgur.com/gDakunQ.png[url]

Now here is 2016/17. Similar setup. Perhaps the +PMM allowed the EPAC rising cell to be taking advantage of.

So it's not an EPAC cell nor is it an American standing wave. We'll see how the VP anomaly maps looks by September. If we do get to Nora or Olaf, then there should be a significant amount of -VP200 anomalies closer to Mexico/120W that will make it look like 2016/2017.

[Kingarabian]

18z GFS all the way to Nora.

[Kingarabian]

Why is the 0/60 diturbance not 50/80? Invest should be up for it. EPS develops it in 72 hours.

12z 16day EPS only shows up to Marty.

[cycloneye]

A broad area of low pressure is expected to develop a few hundred
miles offshore of the southwestern coast of Mexico this weekend.
Environmental conditions are forecast to be conducive for gradual
development thereafter, and a tropical depression could form early
next week while the system moves west-northwestward at 10 to 15 mph,
parallel to and offshore of the coast of southwestern Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...60 percent.

[gatorcane]

18z GFS all the way to Nora.

The EPAC looks to be on fire

[Yellow Evan]

EPS control has favorable conditions for ~12 more days. Likely to get Kevin and Linda by then and maybe Marty.

[Kingarabian]

00z GFS looked a lot more realistic. Only shows two more named system. There is vorticity signature for two more systems but they both don't develop.

00z Euro and CMC go up to Marty.

00z EPS goes up to Nora.

[Category5Kaiju]

For now the NHC still only has one AOI highlighted in the EPAC (which would likely be Kevin). Other than that (at least so far) it does not seem like the NHC is interested in highlighting any additional AOIs that would have been easily highlighted by now should the runs showing continous, copious EPAC activity be believed.

[cycloneye]

1. A large area of disorganized showers and thunderstorms is located
a few hundred miles south of the coast of southwestern Mexico.
Environmental conditions are forecast to be conducive for
additional gradual development, and a tropical depression is likely
to form early next week while the system moves west-northwestward at
about 10 mph, parallel to and offshore of the coast of southwestern
Mexico.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...high...70 percent.

2. An area of low pressure is expected to develop a few hundred miles
southeast of the Gulf of Tehuantepec by early next week.
Environmental conditions are forecast to be conducive for gradual
development thereafter, while the system moves west-northwestward
to northwestward at about 10 mph, parallel to and offshore of the
coast of southern Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

[Yellow Evan]

TXPZ22 KNES 061801
TCSENP

A. TROPICAL DISTURBANCE

B. 06/1730Z

C. 14.2N

D. 101.4W

E. FIVE/GOES-E

F. T1.0/1.0

G. IR/EIR/VIS

H. REMARKS...SYSTEM HAS AN ELONGATED LLCC SEEN BY THE 1436Z ASCAT
PASS. SYSTEM HAS GREATER THAN 2/10 BANDING RESULTING IN A DT OF 1.0. THE
24 HR DEVELOPING TREND RESULTS IN DEVELOPING. MET AND PT ARE 1.0. FT IS
BASED ON DT.

I. ADDL POSITIONS

NIL


...PATEL

[cycloneye]

Invest 92E is up

[Kingarabian]

12z Euro, GFS, CMC, and EPS continue to remain very active over the next two weeks.