2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images

[Yellow Evan]

It is plausible that the summer WAM is causing the summer reversals of AMO and preventing us from a true -AMO phase. Whether this is a sign of a true -AMO pattern down the line or a replacement of a true -AMO phase altogether are up for debate.

If the WAM (or other factors like climate change) are masking us actually now being in a -AMO, it's quite scary what we might see in 15 years when the +AMO phase returns.

By that point, it’s possible WAM could be in a dry phase though, helping offset a +AMO SST configuration.

[CyclonicFury]

It is interesting though for much of the 1995-2012 period the Sahel region of Africa was drier than normal.

[AlphaToOmega]

It is plausible that the summer WAM is causing the summer reversals of AMO and preventing us from a true -AMO phase. Whether this is a sign of a true -AMO pattern down the line or a replacement of a true -AMO phase altogether are up for debate.

If the WAM (or other factors like climate change) are masking us actually now being in a -AMO, it's quite scary what we might see in 15 years when the +AMO phase returns.

By that point, it’s possible WAM could be in a dry phase though, helping offset a +AMO SST configuration.

WAM dry/wet phases seem to coincide with AMO. During +AMO, VP anomalies in West Africa are negative. During -AMO, VP anomalies in West Africa are typically positive.

[Category5Kaiju]

It is interesting though for much of the 1995-2012 period the Sahel region of Africa was drier than normal.

It is indeed; it does make me want to believe that having a wetter Sahel region as well as this summer shift from - to + AMO is still contributing to all of the intense and above average seasons we have seen since 2016. In what exact manner I do not know, but it is intriguing to say the least.

[Yellow Evan]

If the WAM (or other factors like climate change) are masking us actually now being in a -AMO, it's quite scary what we might see in 15 years when the +AMO phase returns.

By that point, it’s possible WAM could be in a dry phase though, helping offset a +AMO SST configuration.

WAM dry/wet phases seem to coincide with AMO. During +AMO, VP anomalies in West Africa are negative. During -AMO, VP anomalies in West Africa are typically positive.

The historic record seems to somewhat agree with this but we don’t have a very long historical record (only 2 -AMO cycles, one of which was drier in Africa than the other).

[NDG]

I believe CDAS daily SSTs charts have a cooler bias over the MDR when dust is present over it, looking at the two images they both match pretty good in all areas except over the MDR.

https://i.imgur.com/rIfm2zU.png
https://i.imgur.com/XnETZPA.png

That is correct. To be more specific, CDAS relies more on satellite derived data input compared to NOAA's Coral Reef Watch products or OISST products. CDAS uses the following satellite spectrums for color:
- 6.925, 10.65 GHz Brightness Temperature (V/H Polarization)
- 23.8, 36.5 GHz Brightness Temperature (H Polarization)

The CDAS documentation states that when data is contaminated by convection/SAL outbreaks (i.e., color spectrum becomes opaque), a formula is implemented that essentially counts the number of pixels within 6 GHz or 10 GHz spatial resolution. We can see from CIMSS SAL products, this has caused an issue with the CDAS data input:

https://i.imgur.com/PYjWzz7.jpg

Makes sense!

[toad strangler]

No deviation in anticipated schedule as of yet

 http://twitter.com/AndyHazelton/status/1416129137698299904

[aspen]

No deviation in anticipated schedule as of yet

http://twitter.com/AndyHazelton/status/1416129137698299904?s=20

Week 2 will still have suppressive air over Africa, but further west might be favorable for a sleeper wave that survives over to there.

[Stormybajan]

No deviation in anticipated schedule as of yet

http://twitter.com/AndyHazelton/status/1416129137698299904?s=20

Based on this, looks like we may have to wait until August 7th for activity to get going again. Elsa formed July 1st so this will be a massive break..even longer than I first thought

[toad strangler]

No deviation in anticipated schedule as of yet

http://twitter.com/AndyHazelton/status/1416129137698299904?s=20

Based on this, looks like we may have to wait until August 7th for activity to get going again. Elsa formed July 1st so this will be a massive break..even longer than I first thought

Anything pre 8/15 ish would be gravy IMO.

[AlphaToOmega]

Remember there was a lull of activity in August 2020. I would caution anyone trying to make "season cancelled" posts just because of this. It is called an unfavorable MJO phase.

[Category5Kaiju]

Also while the deep tropics may be asleep for a bit we could easily get some subtropical action or pop up storms as those seem to be quite frequent in recent years; also given the decently warmer than average subtropics, who knows if we’ll see one or two of these before the “real” action begins?

[Steve]

Agree with the tweets on the MJO not indicating anything for now. Looks to be headed toward Phase 6/7. We might see some bursts within a slow/constant burn season though later on. If we mimic 2020 at all per A/O’s analog, September and October could be cooking. Bursts tend to come in the quick swings down through phases 8-1-2. That’s especially true when patterns are more amplified. We’ll see if the MJO can be a dominant predictor for 2021.

[SFLcane]

Oh Florida…

 https://twitter.com/webberweather/status/1416802320960999425

[cycloneye]

Oh Florida…

https://twitter.com/webberweather/status/1416802320960999425

Oh Lesser Antilles / Puerto Rico.

[SFLcane]

Oh Florida…

https://twitter.com/webberweather/status/1416802320960999425

Oh Lesser Antilles / Puerto Rico.

Yes yes…look out if your in that purple shading.

[SFLcane]

 https://twitter.com/webberweather/status/1416802830774538243

[toad strangler]

:crazyeyes:

https://twitter.com/webberweather/status/1416802830774538243

OK I'll pile on

 http://twitter.com/webberweather/status/1416811738691899396

[AlphaToOmega]

Here is where the ITCZ is likely to be come peak season. Obviously, it is and will be much farther south this year than it was last year.

[SFLcane]

Here is where the ITCZ is likely to be come peak season. Obviously, it is and will be much farther south this year than it was last year.
https://i.postimg.cc/BQ0Q2pYy/itcz.png

Id advise not to use precipitation from climate models to determine potential tropical cyclone tracks. I would take those forecast with caution this season as some of these models are having trouble with Atlantic El Niño and have dry bias. I for one think it probably won’t be a very high number season but more of an impactful year in terms of impacts. I will be ready in SFL as the signs are ominous from looking z500 model output. Just because an area is shaded brown doesn’t mean a tc won’t track through through there.