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

[BYG Jacob]

Worth pointing out that 2009, despite being relatively inactive, turned two of the most impressive El Nino year CV hurricanes in the last decade: Hurricanes Bill and Fred.

Frances and Ivan have those two covered

Ivanhater to the white courtesy phone please

[Eric Webb]

To be fair its not just the Euro, the JMA and CFS show the same thing.

Then something is wrong with all these models wrt the WAM, you don't go from near record territory to much drier than normal in a timeframe like a week or two

I think they're behaving normally when you consider the subsurface pool in the CPAC/EPAC, and the MJO modeled to enter and become "stuck" in the El Nino phases.

It's all wait and see at this point. Mid August will be telling. Eric Blake and Levi Cowan do have a point that this may only be a small 2 week trend in the grand scheme of things.

Levi Cowan and Eric Blake made this statement because they thought the lack of strong, persistent easterly trades was being driven by subseasonal variability. It's extremely obvious with the MJO in the central-western pacific that what we're observing still shouldn't be happening if this was the case, and the next 10 days the trades are going to only get slower even as the east-central MDR appears dry. The drier MDR is arguably even more conducive for more rapid warming because it benefits from both weak trades underneath the AEWs on the northern side of the AEJ and increased insolation that both serve to warm the sea surface, obviously the advection of SAL does block some insolation but this is offset by the lack of large-scale deep convective cloud cover.

I'll say this again, what we are seeing is not temporary because the trade wind variability is being driven by the monsoon (which is a lower frequency, seasonal phenomena and not higher frequency subseasonal forcing (CCKWs/MJO (which both argue for strong trades over the Atlantic atm). Even these big, poleward displaced, dry waves the next week or two (and possibly beyond) will probably inflict quite a bit of damage to the -AMO as the ECMWF shows...

[Kingarabian]

Would African waves crossing into the EPAC also slow trades?

[NotSparta]

:uarrow:

Would African waves crossing into the EPAC also slow trades?

If they still have strong spin when they have crossed, yes.

[gatorcane]

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

https://i.imgur.com/1tEvp6w.gif

The long-range CFS also shows much lower shear anomalies across the entire Atlantic basin come mid to late August compared to now. Wet-phase of MJO + low shear (+possibly warmer than normal SSTs based on latest trends) would mean a favorable setup for development across the MDR. See images below:

Now:


Mid-late August:

[cycloneye]

@MJVentrice
Models are calling for a strong convectively coupled Kelvin wave to pass the Atlantic and Africa regions during the final days of July into the first week of August. This wave could produce some things to monitor over the Atlantic during early August.



 https://twitter.com/MJVentrice/status/1018852529407496193

[TheStormExpert]

I believe the GFS may be starting to pick up on this as in the first day of August it shows something in the Eastern GoM.

[GCANE]

GFS is forecasting the Bermuda High to kick in early next week.

[wxGuy]

Kelvin waves favor tropical cyclogenesis three days after their peak convection, let's see what it has to offer

[cycloneye]

The July update from ECMWF of MSLP for ASO shows higher pressures almost everywhere in the North Atlantic basin.

In July 2017 it was very different.

[NotSparta]

The July update from ECMWF of MSLP for ASO shows higher pressures almost everywhere in the North Atlantic basin.

In July 2017 it was very different.

[img]https://i.imgur.com/v2Q1Nvg.png[img]

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

Where are these forecasts located?

[SFLcane]

The July update from ECMWF of MSLP for ASO shows higher pressures almost everywhere in the North Atlantic basin.

In July 2017 it was very different.

Lol oh boy a complete shut down..

[CyclonicFury]

The July update from ECMWF of MSLP for ASO shows higher pressures almost everywhere in the North Atlantic basin.

In July 2017 it was very different.

Lol oh boy a complete shut down..

The Euro has a high bias when it comes to Atlantic SLP. The CFS shows near-average pressures in the Atlantic for ASO, but I think it may have a low bias (not sure about that).

[Alyono]

EC forecast is for

Starting August 1
8.6 TS (SD of 2.8)
4.6 H (SD of 1.8)

That means, assuming no additional development in July, EC is basically going for 12/7 However, it could easily be as much as 13/8

[CyclonicFury]

EC forecast is for

Starting August 1
8.6 TS (SD of 2.8)
4.6 H (SD of 1.8)

That means, assuming no additional development in July, EC is basically going for 12/7 However, it could easily be as much as 13/8

Isn't that more than the last forecast? IIRC Wxman said the last forecast only called for about 7 NS and 3 H.

[AutoPenalti]

GFS is forecasting the Bermuda High to kick in early next week.

Yep, just in time for August.

Maybe we’ll get a long-trek CV?

[LarryWx]

The July update from ECMWF of MSLP for ASO shows higher pressures almost everywhere in the North Atlantic basin.

In July 2017 it was very different.

Lol oh boy a complete shut down..

The Euro has a high bias when it comes to Atlantic SLP. The CFS shows near-average pressures in the Atlantic for ASO, but I think it may have a low bias (not sure about that).

I think the Euro in general tends to have a high bias with SLPs, but not nearly enough to overcome these very high pressures in this forecast. These pressures are off the chart high.
So, even after taking into account bias, the forecast would still be for above normal SLPs.

[cycloneye]

The July update from ECMWF of MSLP for ASO shows higher pressures almost everywhere in the North Atlantic basin.

In July 2017 it was very different.

[img]https://i.imgur.com/v2Q1Nvg.png[img]

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

Where are these forecasts located?

Here is the link.

https://www.ecmwf.int/en/forecasts/charts/catalogue/seasonal_system5_public_standard_mslp?facets=Range,Long%20(Months)&time=2017070100,744,2017080100&stats=tsum

[SoupBone]

GFS is forecasting the Bermuda High to kick in early next week.

The Bermuda High is an almost constant feature though. Do you mean it's forecast to build west?

[LarryWx]

Per that Euro ASO forecast, be extra vigilant in Hawaii!