2022 EPAC Season

[aspen]

The party continues...

https://i.postimg.cc/4xLCh8G5/gfs.gif

Does the GFS have a problem with getting basins or MJOs stuck in one state and refusing to correctly model changes in favorability and MJO phase?

[Yellow Evan]

The party continues...

https://i.postimg.cc/4xLCh8G5/gfs.gif

Does the GFS have a problem with getting basins or MJOs stuck in one state and refusing to correctly model changes in favorability and MJO phase?

Yes though I don’t think that’s the problem here. It also has been theorized to have issues with monsoon trough breakdowns.

[skyline385]

Looks like EPS also wants the party to continue, so probably not just a GFS issue. There is a good possibility of 2 more systems.

[Category5Kaiju]

It's quite honestly very impressive to see how the EPAC is doing this in a La Nina state while the WPAC and Atlantic remain quiet, especially the former. I've never seen anything like this happen since I started tracking storms in detail in 2019; I know that's a limited sample size tho

[cycloneye]

Offshore of Southern Mexico:
An area of disturbed weather associated with a trough of low
pressure has developed several hundred miles offshore of southern
Mexico. Some gradual development of this system is possible by this
weekend or early next week while it moves slowly westward to
west-northwestward at 5 to 10 mph.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...30 percent.

[Ntxw]

It's quite honestly very impressive to see how the EPAC is doing this in a La Nina state while the WPAC and Atlantic remain quiet, especially the former. I've never seen anything like this happen since I started tracking storms in detail in 2019; I know that's a limited sample size tho

Read something that showed some resemblance of an Atlantic Nina being supressive of waves into South America. Extrapolation one would think they would have a better shot at tracking over the EPAC in that path than usual. It's pretty uncommon to have a Pacific and Atlantic Nina, tendency being.. you guessed it third year Ninas. 2000 and 2011 have pretty comparable SSTA. North Pacific being a great match.










Source: https://cpaess.ucar.edu/sites/default/files/meetings/2020/presentations/kim-presentation.pdf

In short I'd guess that's the bar in terms of ACE for the EPAC between those two seasons.

[Category5Kaiju]

GFS seems to completely drop the 10/30 AOI and now developing canes in early August.

[Kingarabian]

Back to back runs on the GFS with delayed EPAC development. 00z GFS actually has some Caribbean and GOM development. Looks like its EPAC bias is slowly phasing out with each run. That being said, there is still a good chance for another system before August.

[Yellow Evan]

This is why you look at the ensemble runs as well which still has activity in the last week of July.

[Yellow Evan]

 https://twitter.com/andyhazelton/status/1550097802126032898

[Yellow Evan]

It's quite honestly very impressive to see how the EPAC is doing this in a La Nina state while the WPAC and Atlantic remain quiet, especially the former. I've never seen anything like this happen since I started tracking storms in detail in 2019; I know that's a limited sample size tho

Read something that showed some resemblance of an Atlantic Nina being supressive of waves into South America. Extrapolation one would think they would have a better shot at tracking over the EPAC in that path than usual. It's pretty uncommon to have a Pacific and Atlantic Nina, tendency being.. you guessed it third year Ninas. 2000 and 2011 have pretty comparable SSTA. North Pacific being a great match.

https://i.imgur.com/Q3Pqy7K.png

https://i.imgur.com/hLkZWsx.png

https://i.imgur.com/OKq1Zd1.png


https://i.imgur.com/XTS2iFw.png

Source: https://cpaess.ucar.edu/sites/default/files/meetings/2020/presentations/kim-presentation.pdf

In short I'd guess that's the bar in terms of ACE for the EPAC between those two seasons.

First off all, there’s no Atlantic Niña right now at least yet though I would not be surprised if one occurs fairly soon. SST’s near the equator in the Atlantic are running near average. It also tends to lift the ITCZ northward, which limits early season activity in the ATL due to its proximity to the SAL, but if in association of a +AMM, weakens trades off of Africa and is linked with a stronger WAM. Most tropical waves make it to the EPAC regardless this time of year and even if they don’t the monsoon trough can act as a genesis source especially under the right intraseasonal base state.

With that said, anecdotally, the EPAC monsoon trough seems more equatorial than usual for a +AMO despite the -SPMM (perhaps because the equator is fairly warm), which is giving the systems more time over warm SSTs. La Niña shifting genesis further east has also helped for similar reasons. Reminds me a lot of the La Niña setups from the last -AMO, particularly in the 1970s.

[Ntxw]

First off all, there’s no Atlantic Niña right now at least yet though I would not be surprised if one occurs fairly soon. SST’s near the equator in the Atlantic are running near average. It also tends to lift the ITCZ northward, which limits early season activity in the ATL due to its proximity to the SAL, but if in association of a +AMM, weakens trades off of Africa and is linked with a stronger WAM. Most tropical waves make it to the EPAC regardless this time of year and even if they don’t the monsoon trough can act as a genesis source especially under the right intraseasonal base state.

With that said, anecdotally, the EPAC monsoon trough seems more equatorial than usual for a +AMO despite the -SPMM (perhaps because the equator is fairly warm), which is giving the systems more time over warm SSTs. La Niña shifting genesis further east has also helped for similar reasons. Reminds me a lot of the La Niña setups from the last -AMO, particularly in the 1970s.

It's very nice to see CFSv2 page from NOAA incorporate the Atlantic Nino forecasts and can only help with future predictability, more tools! You are correct it's currently not one but it is skewed cooler than the past several seasons, so I treated as trending in that direction specifically for ASO.

https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html

[skyline385]

First off all, there’s no Atlantic Niña right now at least yet though I would not be surprised if one occurs fairly soon. SST’s near the equator in the Atlantic are running near average. It also tends to lift the ITCZ northward, which limits early season activity in the ATL due to its proximity to the SAL, but if in association of a +AMM, weakens trades off of Africa and is linked with a stronger WAM. Most tropical waves make it to the EPAC regardless this time of year and even if they don’t the monsoon trough can act as a genesis source especially under the right intraseasonal base state.

With that said, anecdotally, the EPAC monsoon trough seems more equatorial than usual for a +AMO despite the -SPMM (perhaps because the equator is fairly warm), which is giving the systems more time over warm SSTs. La Niña shifting genesis further east has also helped for similar reasons. Reminds me a lot of the La Niña setups from the last -AMO, particularly in the 1970s.

It's very nice to see CFSv2 page from NOAA incorporate the Atlantic Nino forecasts and can only help with future predictability, more tools! You are correct it's currently not one but it is skewed cooler than the past several seasons, so I treated as trending in that direction specifically for ASO.

https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html

Didn’t know they were doing that. On another note, this model forecast is kinda hilarious, they got all bases covered lol

[Ntxw]

First off all, there’s no Atlantic Niña right now at least yet though I would not be surprised if one occurs fairly soon. SST’s near the equator in the Atlantic are running near average. It also tends to lift the ITCZ northward, which limits early season activity in the ATL due to its proximity to the SAL, but if in association of a +AMM, weakens trades off of Africa and is linked with a stronger WAM. Most tropical waves make it to the EPAC regardless this time of year and even if they don’t the monsoon trough can act as a genesis source especially under the right intraseasonal base state.

With that said, anecdotally, the EPAC monsoon trough seems more equatorial than usual for a +AMO despite the -SPMM (perhaps because the equator is fairly warm), which is giving the systems more time over warm SSTs. La Niña shifting genesis further east has also helped for similar reasons. Reminds me a lot of the La Niña setups from the last -AMO, particularly in the 1970s.

It's very nice to see CFSv2 page from NOAA incorporate the Atlantic Nino forecasts and can only help with future predictability, more tools! You are correct it's currently not one but it is skewed cooler than the past several seasons, so I treated as trending in that direction specifically for ASO.

https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html

Didn’t know they were doing that. On another note, this model forecast is kinda hilarious, they got all bases covered lol

https://uploads.tapatalk-cdn.com/20220721/4f0c464d27d44d902cb0fefb7cd0a584.jpg

It's a fairly new feature and not sure of the skill scores . There isn't even a real designation that sets standards what values are needed for an 'Atl Nino/Nina' as far as I know. Its value is looking at the trends longer term.

[Kingarabian]

This is why you look at the ensemble runs as well which still has activity in the last week of July.

They show a weak TC for the most part. Which is very possible.

[SFLcane]

 https://twitter.com/AndyHazelton/status/1550153373374156803

[Yellow Evan]

This is why you look at the ensemble runs as well which still has activity in the last week of July.

They show a weak TC for the most part. Which is very possible.

Yes but they're of lower resolution than the operational so that's to be expected. The op GFS reminds me a bit of some of its pre-Darby and Estelle runs when the GFS dropped development for a little while due to showing the AEW interacting with the monsoon trough and becoming elongated and in both those cases, the GFS eventually brought it back and the system developed. This might not happen this go around but as long as this stays at a low latitude, it warrants keeping an eye on.

[Yellow Evan]

Actually 12z GFS never breaks down the monsoon trough from the 10/30 so losing confidence in that now.

[cycloneye]

GFS now has only one developing at long range and has abandoned those 3-4 ones.

[cycloneye]

Euro forms the 10/30 AOI.