2018 EPAC Season

[cycloneye]

Wow,PPM has crashed so it means EPAC wont be as busy as thought?

@webberweather
The PMM usually decays in the summer once the mid-latitude wintertime RW forcing goes away but the circumglobal subtropical ridging strengthened the trades here resulting in a massive PMM crash.



 https://twitter.com/webberweather/status/1015601281316970496

[Kingarabian]

Wow,PPM has crashed so it means EPAC wont be as busy as thought?

@webberweather
The PMM usually decays in the summer once the mid-latitude wintertime RW forcing goes away but the circumglobal subtropical ridging strengthened the trades here resulting in a massive PMM crash.

[img]https://i.imgur.com/XjYVKmZ.jpg[img]

[tweet]https://twitter.com/webberweather/status/1015601281316970496[tweet]

Maybe it'll allow for more ATL systems than previously thought, although that basin still has a big negative factor with the AMM being that cool.

In the EPAC it should still be a bullish season. We're in a developing El Nino, so waters (at least west of 100W) will be warm than average.

CFS also shows very favorable VP anomalies for much of the CPAC/EPAC basin soon:

[Yellow Evan]

PNM/PDO tends to fall apart this time of year not to mentioned part of the basin cooled of due to upwelling.

[NotSparta]

GFS has very strong trades, would keep basin quiet

[Kingarabian]

Those are 5 days averages, so it's not that extreme. We'll always see pockets of unfavorable shear and favorable shear. Just need a disturbance to be in the right place at the right time. Don't forget that TCs are capable of "improving" local shear conditions.

Just need an igniter to spur development right now (Kelvin wave).There's a lot of low pressure areas lined up.

[Yellow Evan]

I will say, in this case, that the trades relaxing in the central Atlantic, would further hint to a 2017 pattern in both basins.

[NotSparta]

I will say, in this case, that the trades relaxing in the central Atlantic, would further hint to a 2017 pattern in both basins.

While the EPAC now has that filament of cooler SSTs like last spring, I have a feeling the EPAC still manages an above average season.

And while trades should relax, SSTAs in the ATL MDR shouldn't come close to 2017's -- there's still a decent -AMM and it'll take a lot of work to even get to a marginal +AMM, let alone 2017 levels.

Also, unlike 2017, it looks like ENSO will move into El Niño this yr rather than going back to La Niña, especially since its base state has been erased.
Just saying my $0.02, I could be wrong.

[NotSparta]

Those are 5 days averages, so it's not that extreme. We'll always see pockets of unfavorable shear and favorable shear. Just need a disturbance to be in the right place at the right time. Don't forget that TCs are capable of "improving" local shear conditions.

Just need an igniter to spur development right now (Kelvin wave).There's a lot of low pressure areas lined up.

True, true (though a 5 day average indicates it could be even more extreme at points, and also less). TCs can be unpredictable, so they can pop up unexpectedly.

[NotSparta]

Not sure how reliable it is or whether it'll verify, but the CFSv2 weekly keeps trades fast:

[Yellow Evan]

EPS has been trying to hint at stuff after day 10 but you know the drill given the phantom storms we've seen the last season and a half.

[Kingarabian]

EPS has been trying to hint at stuff after day 10 but you know the drill given the phantom storms we've seen the last season and a half.

I remember when the EPS had something, it was serious. Now it's just as bad the GFS. So many ghost storms in the past 2 weeks on it...

[cycloneye]

Kingarabian,when will we know when the models will be right about something developing in this basin as you said about the phantoms they have been showing?.

[Yellow Evan]

Kingarabian,when will we know when the models will be right about something developing in this basin as you said about the phantoms they have been showing?.

In theory, by the book meteorology says when there's more consistency but as of right now, we will know something is developing when it actually happens.

[hurricanes1234]

I don't think this month we'll see the long streak of July storms we've been accustomed to for the last three years because it's already July 8 and the models seem to at least be correctly forecasting the inactive periods. As for whether or not it'll happen in August, I guess only time will tell.

[Kingarabian]

Well speaking of development, GFS for the 2nd run in a row shows a disturbance emerging from a vigorous ITCZ/MT consolidating and developing to become TS Gilma near 120-130W:



It makes sense since there's about to be a surge of favorable VP anomalies entering the CPAC/EPAC. As a result, the operational models should begin to show more signs of TC genesis (as soon as they get a better handle).

[Kingarabian]

Very likely that we'll see an uptick in TC development in the CPAC/EPAC soon:

 https://twitter.com/MJVentrice/status/1016031493645393921

[Yellow Evan]

A few EPS members and NASA show this now. Some EPS members also seemingly showing stuff behind it.

[Yellow Evan]

June SST's only the 7th highest on record. Second lowest after 2017 since 2014. Also behind 1997 and a few earlier seasons. If it continues, that'd signify a pattern flip from the ultrafavorable EPAC expected some earlier, although more so from others.

[Kingarabian]

Latest 00z OP. Euro run and EPS run look very bullish for development starting around the 15th.



PC - Ryan Maue - http://www.weathermodels.com

[Kingarabian]

06z GFS now on board with development. Has TS Gilma in 72 hours. Probably see the NHC take the yellow marker out soon.