2020 Indicators: SST's / SAL / MSLP / Steering / Shear / Instability / Sat Images

[USTropics]

The CFS has shown a long tracker the past 5 runs, with varying degrees of intensity each run the last week of July/beginning of August. Track seems to be through the Bahamas/Caribbean:


This is the wave most likely to watch:

[MarioProtVI]

The CFS has shown a long tracker the past 5 runs, with varying degrees of intensity each run the last week of July/beginning of August. Track seems to be through the Bahamas/Caribbean:
https://i.ibb.co/wgsD2Mv/Webp-net-gifmaker-4.gif

This is the wave most likely to watch:
https://i.imgur.com/2On4Yzo.png

That 993 in the Gulf concerns me especially at that resolution - even though it is way out there at this resolution that could be probably be a strong hurricane (of around C2-3 perhaps).

[toad strangler]

All of these models and fancy graphics, tweets, etc might look ominous but let’s face it, there is just little skill in long-range forecasting of tropical cyclones. That’s why all of the “indicators” should be taken with a grain of salt. The main signal it could be active in the Atlantic is because of the above normal SSTs across the Atlantic in the MDR and lack of El Niño. It should be active and above normal but just wouldn’t be too quick to say that it equates to active landfall season. The other thing is that there is no sign in the models for any WPAC activity. It is early but as we head into July would expect to see something. There could easily be something else we can’t see yet that helps suppress global cyclone activity more than expected including the Atlantic.

Well if all the indicators should be taken like a grain of salt that would mean this entire thread should be. And I would say this thread is the backbone of this forum.

[Shell Mound]

 https://twitter.com/webberweather/status/1280581682068946944









Does anyone know why the latest NMME shows drier conditions over the northern MDR, southwestern Atlantic, western Caribbean, and most of the Gulf of Mexico compared to its previous run? Is this related to the fact that the latest CFSv2, one of the models used in compiling the NMME, is showing a very strong TUTT over most of the basin during the month of August? The CFSv2 shows El Niño-like VWS during the month of August, while the E/CPAC is actually rather favourable. What could be causing that? Note that the CFSv2, like the NMME, also shows a very pronounced warm pool over the subtropical northwestern Atlantic, despite an otherwise favourable setup with cool neutral ENSO/weak La Niña, weak -IOD, -PDO, +AMO (in the deep tropics), and strong WAM/AEJ? (Notably, the latest NMME really strengthens La Niña and the rising branch over the MC during ASO.)

[cycloneye]

All of these models and fancy graphics, tweets, etc might look ominous but let’s face it, there is just little skill in long-range forecasting of tropical cyclones. That’s why all of the “indicators” should be taken with a grain of salt. The main signal it could be active in the Atlantic is because of the above normal SSTs across the Atlantic in the MDR and lack of El Niño. It should be active and above normal but just wouldn’t be too quick to say that it equates to active landfall season. The other thing is that there is no sign in the models for any WPAC activity. It is early but as we head into July would expect to see something. There could easily be something else we can’t see yet that helps suppress global cyclone activity more than expected including the Atlantic.

Well if all the indicators should be taken like a grain of salt that would mean this entire thread should be. And I would say this thread is the backbone of this forum.

Every year the indicator threads are the source for information to the members about all the factors leading to a season.

[AutoPenalti]

That's a lot of shear for August... what MDR system is going to survive that trek?

[cycloneye]

 https://twitter.com/BenNollWeather/status/1281234150385729536

[JetFuel_SE]

https://twitter.com/webberweather/status/1280581682068946944
https://pbs.twimg.com/media/EcWJ5wJXkAEJ1qs?format=jpg&name=medium
https://www.cpc.ncep.noaa.gov/products/NMME/current/images/NMME_ensemble_tmpsfc_season1.png
https://www.cpc.ncep.noaa.gov/products/NMME/current/images/NMME_ensemble_prate_season1.png
https://www.tropicaltidbits.com/analysis/models/cfs-mon/2020070818/cfs-mon_01_ashear_atl_1.png
https://www.tropicaltidbits.com/analysis/models/cfs-mon/2020070818/cfs-mon_01_ssta_atl_1.png

Does anyone know why the latest NMME shows drier conditions over the northern MDR, southwestern Atlantic, western Caribbean, and most of the Gulf of Mexico compared to its previous run? Is this related to the fact that the latest CFSv2, one of the models used in compiling the NMME, is showing a very strong TUTT over most of the basin during the month of August? The CFSv2 shows El Niño-like VWS during the month of August, while the E/CPAC is actually rather favourable. What could be causing that? Note that the CFSv2, like the NMME, also shows a very pronounced warm pool over the subtropical northwestern Atlantic, despite an otherwise favourable setup with cool neutral ENSO/weak La Niña, weak -IOD, -PDO, +AMO (in the deep tropics), and strong WAM/AEJ? (Notably, the latest NMME really strengthens La Niña and the rising branch over the MC during ASO.)

That precipitation anomaly image is just the change compared to the June forecast, it's basically this but precipitation anomalies.

[Shell Mound]

That's a lot of shear for August... what MDR system is going to survive that trek?

What’s even more surprising is that no one is really mentioning it, much less probing for causes. The shear even shows at 200 mb over the western MDR:





Also, that strong subtropical jet extending from the eastern North Pacific all the way over the Atlantic seems more like an El Niño-type setup. Strange!

[tarheelprogrammer]

That's a lot of shear for August... what MDR system is going to survive that trek?

What’s even more surprising is that no one is really mentioning it, much less probing for causes. The shear even shows at 200 mb over the western MDR:

https://www.tropicaltidbits.com/analysis/models/cfs-mon/2020070900/cfs-mon_01_u200a_atl_1.png

https://www.tropicaltidbits.com/analysis/models/cfs-mon/2020070900/cfs-mon_01_ashear_atl_1.png

Could the shear shown in the MDR be the direct result of an active wave train throughout the MDR? Could hyper activity result in increased shear in that area that is above normal?

[SFLcane]

https://twitter.com/webberweather/status/1280581682068946944
https://pbs.twimg.com/media/EcWJ5wJXkAEJ1qs?format=jpg&name=medium
https://www.cpc.ncep.noaa.gov/products/NMME/current/images/NMME_ensemble_tmpsfc_season1.png
https://www.cpc.ncep.noaa.gov/products/NMME/current/images/NMME_ensemble_prate_season1.png
https://www.tropicaltidbits.com/analysis/models/cfs-mon/2020070818/cfs-mon_01_ashear_atl_1.png
https://www.tropicaltidbits.com/analysis/models/cfs-mon/2020070818/cfs-mon_01_ssta_atl_1.png

Does anyone know why the latest NMME shows drier conditions over the northern MDR, southwestern Atlantic, western Caribbean, and most of the Gulf of Mexico compared to its previous run? Is this related to the fact that the latest CFSv2, one of the models used in compiling the NMME, is showing a very strong TUTT over most of the basin during the month of August? The CFSv2 shows El Niño-like VWS during the month of August, while the E/CPAC is actually rather favourable. What could be causing that? Note that the CFSv2, like the NMME, also shows a very pronounced warm pool over the subtropical northwestern Atlantic, despite an otherwise favourable setup with cool neutral ENSO/weak La Niña, weak -IOD, -PDO, +AMO (in the deep tropics), and strong WAM/AEJ? (Notably, the latest NMME really strengthens La Niña and the rising branch over the MC during ASO.)

That's a 2013 look with Massive wavebreaking. Somebody is going to bust IF the CFS is correct.

[SFLcane]

Phil k forecast are usually solid so the CFS might be out to lunch. It’s a pretty bad climate model. Gotta see how things actually evolve

[Siker]

CFS has been overly progressive with the African Standing Wave. Eric Webb posted an analysis yesterday (not on Twitter I don't think) demonstrating that its forecast from several weeks ago, which shifted upward motion away from Africa by mid-July, busted badly. The CFS shows downward motion focused over Africa in August, a reversal of the current pattern that's largely been in place since May. It's certainly possible that subseasonal favorability shifts away from Africa during August, but given the persistence of the ASW and recent failures of the CFS I wouldn't count on it.

[tolakram]

What is the verification of those shear models? I doubt it's very high. Nothing new in my opinion, and if/when conditions improve it will take most by surprise, like it always does.

[cycloneye]

 https://twitter.com/AndyHazelton/status/1281308278593642497

[KAlexPR]

https://twitter.com/AndyHazelton/status/1281308278593642497

That product is not very reliable. It showed below average stability during September 2017 when we had three simultaneous hurricanes.

 https://twitter.com/cyclonicwx/status/1281311828300247048



 https://twitter.com/cyclonicwx/status/1281315222029033475

[Hammy]

Any clue as to what's causing the nonstop lack of instability/dryness in the Atlantic? This seems like an ongoing factor since 2011.

[cycloneye]

 https://twitter.com/DRmetwatch/status/1281342544912285696

[StruThiO]

What trades?

[TheStormExpert]

Any clue as to what's causing the nonstop lack of instability/dryness in the Atlantic? This seems like an ongoing factor since 2011.

Where seasons like 2017, 2018, and 2019 not enough to prove that the instability graphic is flawed?