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

[BYG Jacob]

Gonna be another long year

[Iceresistance]

End of April SST Anomalies in the Atlantic, this is not looking good . . .

[Category5Kaiju]

End of April SST Anomalies in the Atlantic, this is not looking good . . .

https://s3.gifyu.com/images/crw_ssta_natl.png

That Canary Current is clearly abnormally warm; also Atlantic Nino 3 is expected to significantly warm up in the coming months; currently the sst anomalies off the west coast of Africa south of the equator are also quite high.

[Shell Mound]

 https://twitter.com/cyclonicwx/status/1387489886022901761

[AutoPenalti]

For those of us in SFL better hope this isn't correct with regards to the CFS. The mean position of the trough in August is basically the same as Irma in 2017. Lots of time still but an eye opener for sure.

https://i.imgur.com/BuB5LPk.png

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

That is NOT. GOOD.

[AutoPenalti]

 https://twitter.com/tropicalblognet/status/1387492549254844419

[aspen]

https://twitter.com/tropicalblognet/status/1387492549254844419

Woah, the ITCZ is really far south. Does its position at this time of year have any impact on its position by ASO?

[DorkyMcDorkface]

https://twitter.com/tropicalblognet/status/1387492549254844419

Woah, the ITCZ is really far south. Does its position at this time of year have any impact on its position by ASO?

It's actually only slightly S of average at the present time.



It's going to continue to gradually rise into the summer so the current position doesn't hold too much significance really. At the same time though you don't want the ITCZ to come too far north because that's how you get potent SAL outbreaks in addition to waves running into cooler SSTs.

[AutoPenalti]

I just thought of something, wouldn't the ITCZ being further north combined with an active WAM also create stronger outbreaks of SAL?

[Category5Kaiju]

I just thought of something, wouldn't the ITCZ being further north combined with an active WAM also create stronger outbreaks of SAL?

I think that's what happened last year? Although I am not quite so sure about how last year compares with 2005 in that aspect; at least in 2005 the SAL seemed to not be an issue one bit as two major storms in July occurred.

[NotSparta]

https://twitter.com/cyclonicwx/status/1387489886022901761
https://i.postimg.cc/bNx04fFv/AK1teys-NUp.png
https://i.postimg.cc/Hky8Q0Lf/SH6bl-M5m-Yz.png
https://i.postimg.cc/YSBG84Gj/4s7ooh4-MQm.png

April data isn't quite available yet so you're just comparing to a blank map for now. See April 2017-20:



We'll have to check back with this once the data becomes available in a few days. I, for one, am expecting it is warmer where the Canary current is than it has been the past few years in the data

[cycloneye]

Big dust storm in Central Africa and now we wait to see if it emerges Africa so dense like this.

 https://twitter.com/RAM_meteo/status/1388482862727446529




 https://twitter.com/RAM_meteo/status/1388484158423453698

[SFLcane]

Status quo… busy season still looks very likely. With the steering on the CFS I am quite concerned for Florida this year.

 https://twitter.com/bennollweather/status/1388523356069105665

[toad strangler]

For those of us in SFL better hope this isn't correct with regards to the CFS. The mean position of the trough in August is basically the same as Irma in 2017. Lots of time still but an eye opener for sure.

https://i.imgur.com/BuB5LPk.png

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

egads, glad these signals are 3 months plus out
But will be fully prepped by July that's for sure. As we all should be no matter the long range forecast

[AnnularCane]

Two weeks till the first TWOs come out.

Barring any surprises.

[Shell Mound]

Status quo… busy season still looks very likely. With the steering on the CFS I am quite concerned for Florida this year.

https://twitter.com/bennollweather/status/1388523356069105665

 https://twitter.com/Nichola76551479/status/1388563882076086276




Niño 1+2: 0°–10°S, 90°W–80°W
Niño 3: 5°N–5°S, 150°W–90°W
Niño 3.4 (ONI): 5°N–5°S, 170°W–120°W
Niño 4: 5°N–5°S, 160°E–150°W

Sources: A, B




Based on these data, 1998 was actually a classical Niña, with its coldest SST anomalies in Niño 3.4, whereas 2008’s were clearly in Niño 4 (west-based). Clearly, the hyperactive 1998 season ended up with much higher seasonal ACE (~182) than the merely above-normal 2008 (~146) because its Niña was centred farther east, so the easternmost equatorial Pacific was cooler in Niño 1+2 than it was in 2008. So a west-based Niña on the CanSIPS actually would mean warmer SST closer to coastal South America, implying more convection over the EPAC TC-genesis region and thus increased VWS and sinking air over the Caribbean and western MDR. The CanSIPS solution thus would likely result in somewhat less intense Atlantic TC activity and lower ACE, even with the active African monsoon playing a role in negating the unfavourable ramifications somewhat. The CanSIPS solution would also imply a stronger TUTT over the deep tropics and also a Bermuda High that is farther northeast, suggesting a greater potential for storms forming in the (eastern) MDR to curve OTS, whereas a central- or east-based Niña would tend to weaken the TUTT and bring the Bermuda High’s axial extension farther west, increasing the risk of major landfalls in the Caribbean and on the CONUS. So the west-based CanSIPS run is actually relatively good news for the Atlantic vs. a classical or east-based Niña (or a west-based Niño).

[Kingarabian]

While anything is possible this year, I'm not so sure Modoki La Nina is in the cards yet. It's not even present and other than what some of these models are showing, currently there's nothing to support such a development. The Nino 4 and Nino 3.4 regions are currently much warmer than the Nino 3 and Nino 1+2 regions. In Modoki La Nina's, Nino 4 and Nino 3.4 are much cooler than Nino 3 and Nino 1+2.

[Shell Mound]

While anything is possible this year, I'm not so sure Modoki La Nina is in the cards yet. It's not even present and other than what some of these models are showing, currently there's nothing to support such a development. The Nino 4 and Nino 3.4 regions are currently much warmer than the Nino 3 and Nino 1+2 regions. In Modoki La Nina's, Nino 4 and Nino 3.4 are much cooler than Nino 3 and Nino 1+2.

The April ECMWF plume for Niño 1+2 seems to have verified considerably better than the March forecast, and it shows significant warming during MJJ, with a west-based Niña evolving by ASO. The CanSIPS shows this general evolution as well, likely due to CCKW activity + active MJO + subsurface warming. So I think there is a good chance that the warm anomalies in Niño 4+3.4 will subside over the coming months, while westerly wind anomalies focused over the eastern Niño zones will result in considerable warming there, especially relative to the western zones. This will end up reinforcing the “Modoki”-type Niña signature, given MJO-modulated periods of enhanced trades will tend to concentrate near the IDL. This will, in my view, end up being at least somewhat detrimental to Atlantic TC activity, particularly ACE, and also result in a less conducive steering regime to landfalls. We shall see.

[ClarCari]

There doesn’t seem to be alot of evidence for La Niña, Modiki or actual La Niña for this season just as much there not being much evidence for a warm ENSO.
I don’t care how much the SUBsurface East ENSO regions warm, it means nothing for this year if the actual surface doesn’t sufficiently warm for this season and I don’t see that happening for 2021.
Even Cool Neutral ENSO technically means a slightly more active EPAC season than what we saw last year and 2010 and therefor a not-as-much favorable as 2020 and 2005 Caribbean year, ( hence the slightly drier than average moisture models over the Caribbean) but I’d be fooling myself and everybody else into thinking that will impact the overall potential hyperactivity in the ATL for 2021 that much.

[Category5Kaiju]

Many of these models (CanSIPS especially) are predicting a wetter than average Bahamas and Florida