2018 Indicators: SST's / MSLP / Sal / Steering / Shear / Instability (Graphic updates at first post)

[CyclonicFury]

It looks like the PMM had collapsed somewhat. Are there any indications/forecasts that show the PMM going stronger/more positive again??


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Climate models like to, but the GFS & CFS keep EP trades much stronger than avg, meaning a possibility for a -PMM pattern, imo

Waters W/SW of Baja California have drastically rewarmed this past week:



Also noticeably warmer so far compared to last month at this time:

That's only a tiny portion of the Pacific. Overall, the PMM has significantly weakened since May. This typically happens during the summer, but not quite to this extent.

[Kingarabian]

Climate models like to, but the GFS & CFS keep EP trades much stronger than avg, meaning a possibility for a -PMM pattern, imo

Waters W/SW of Baja California have drastically rewarmed this past week:

[img]https://i.imgur.com/Ry3361s.png[img]

Also noticeably warmer so far compared to last month at this time:

[img]https://i.imgur.com/eWXjDPa.gif[img]

That's only a tiny portion of the Pacific. Overall, the PMM has significantly weakened since May. This typically happens during the summer, but not quite to this extent.

The PMM is not the SST's of the entire CPAC and EPAC. Per its definition, its SST config is also very dependent on the waters off Baja California. So the warming we're seeing is not really a tiny portion.

[NotSparta]

imo, there's a potential +AMM bkg state setting up

 https://twitter.com/NotSparta_wx/status/1017148562579312640

[cycloneye]

@BenNollWeather
Conditions across the deep tropical Atlantic will be unfavorable for organized development over the next several weeks as atmospheric patterns lean in the direction of El Niño.

Don't sleep on the sub-tropical Atlantic, however.

 https://twitter.com/BenNollWeather/status/1017358030139113472

[AutoPenalti]

Season doesn’t really ramp up till August-September, but worth keeping a look out.

[Eric Webb]

The upward tear continues, as long as we at least have weaker trades in the east-central Atlantic associated w/ the WAM/monsoon trough, we should stave off a huge surge in cooling or continuing warming when the MJO gets closer to the central-east Pacific. Most of the spring-summer SST difference U850 anomaly composites I looked at only showed significant slowing of the trades east of the Antilles and many years where the MDR warmed a lot in the summer actually had beefier trades in/around the Caribbean and Antilles vs those that cooled off.

[Siker]

The upward tear continues, as long as we at least have weaker trades in the east-central Atlantic associated w/ the WAM/monsoon trough, we should stave off a huge surge in cooling or continuing warming when the MJO gets closer to the central-east Pacific. Most of the spring-summer SST difference U850 anomaly composites I looked at only showed significant slowing of the trades east of the Antilles and many years where the MDR warmed a lot in the summer actually had beefier trades in/around the Caribbean and Antilles vs those that cooled off.

Similar to what I asked a few days ago, what sort of changes in Caribbean SST anomalies occurred during your set of years? Did they also warm or was the change in the Eastern Atlantic great enough to offset any cooling (or lack of change) in the Caribbean when looking at the final areal averages?

[Eric Webb]

The upward tear continues, as long as we at least have weaker trades in the east-central Atlantic associated w/ the WAM/monsoon trough, we should stave off a huge surge in cooling or continuing warming when the MJO gets closer to the central-east Pacific. Most of the spring-summer SST difference U850 anomaly composites I looked at only showed significant slowing of the trades east of the Antilles and many years where the MDR warmed a lot in the summer actually had beefier trades in/around the Caribbean and Antilles vs those that cooled off.

Similar to what I asked a few days ago, what sort of changes in Caribbean SST anomalies occurred during your set of years? Did they also warm or was the change in the Eastern Atlantic great enough to offset any cooling (or lack of change) in the Caribbean when looking at the final areal averages?

Amazingly, the Caribbean still warmed albeit only slightly in these years that warmed a lot in the summer. The biggest changes occurred in the eastern Atlantic but the entire MDR as a whole warmed. These years that warmed the most in the MDR started off from a significantly cooler base state in the spring.

MAM SST difference years that warmed the most in the MDR - years that cooled the most in the MDR



JJA SST difference years that warmed the most in the MDR - years that cooled the most in the MDR

[NotSparta]

This huge tropical wave is a great demonstration of how the active WAM will slow the trades over the MDR.

On the southern side of these waves, trade winds are suppressed significantly, and as they pass, you're left with SW wind anoms.

[SoupBone]

This huge tropical wave is a great demonstration of how the active WAM will slow the trades over the MDR.

On the southern side of these waves, trade winds are suppressed significantly, and as they pass, you're left with SW wind anoms.

Beyond weaker steering of systems, what other affect will these potentially have?

[NotSparta]

This huge tropical wave is a great demonstration of how the active WAM will slow the trades over the MDR.

On the southern side of these waves, trade winds are suppressed significantly, and as they pass, you're left with SW wind anoms.

Beyond weaker steering of systems, what other affect will these potentially have?

Causes warming of the MDR, which we are seeing currently

[KimmieLa]

This huge tropical wave is a great demonstration of how the active WAM will slow the trades over the MDR.

On the southern side of these waves, trade winds are suppressed significantly, and as they pass, you're left with SW wind anoms.

Beyond weaker steering of systems, what other affect will these potentially have?

Causes warming of the MDR, which we are seeing currently

So, does this mean that there will be no El Nino for awhile? Or, do I have this backwards??

[tolakram]

This is Atlantic sea surface temps which have no bearing on el nino. Pacific waters in the nino regions are slowly warming and it appears there will be an el nino by winter, possibly by fall.

[NotSparta]

This is Atlantic sea surface temps which have no bearing on el nino. Pacific waters in the nino regions are slowly warming and it appears there will be an el nino by winter, possibly by fall.

There is some bearing on ENSO, the warmer TATL would tend to suppress an El Niño. They can still occur if other factors are in favor of one, though.

[Kingarabian]

Some good chatter on Twitter from Dr. Ventrice and Dr.Klotzbach in regards to the trades:

 https://twitter.com/philklotzbach/status/1017393639453089792

[Eric Webb]

If the EPS is correct, the easterly trade winds will be even weaker the rest of July over the Atlantic MDR than what we've seen the past few weeks. This favors continued warming of the MDR for the foreseeable future in spite of MJO interference. Really interested to see what will happen the next time subseasonal forcing aligns over the Atlantic, Africa, and the Indian Ocean.

[Kingarabian]

If the EPS is correct, the easterly trade winds will be even weaker the rest of July over the Atlantic MDR than what we've seen the past few weeks. This favors continued warming of the MDR for the foreseeable future in spite of MJO interference. Really interested to see what will happen the next time subseasonal forcing aligns over the Atlantic, Africa, and the Indian Ocean.

[img]https://pbs.twimg.com/media/Dh6HwjVWsAAyS3o.jpg:large[mg]

Unless the MJO sits in the EPAC, it'll likely be around the 2nd week of August when favorable VP200 anomalies enter the GOM/Atlantic.

[NotSparta]

If the EPS is correct, the easterly trade winds will be even weaker the rest of July over the Atlantic MDR than what we've seen the past few weeks. This favors continued warming of the MDR for the foreseeable future in spite of MJO interference. Really interested to see what will happen the next time subseasonal forcing aligns over the Atlantic, Africa, and the Indian Ocean.

[img]https://pbs.twimg.com/media/Dh6HwjVWsAAyS3o.jpg:large[img]

Seems it comes around to a favorable state by about mid-August

[NotSparta]

CFS is trending lower w/ MDR pressures for August.

[AutoPenalti]

CFS is trending lower w/ MDR pressures for August.

https://i.imgur.com/mRXSUVU.gif

Looks like it's going to perfectly coincide with the active part of the season (Aug-Sept).