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

[TheStormExpert]

Just keeps getting better! Euro predicting a stronger then normal Bermuda high for Aug,Sept,Oct

https://twitter.com/webberweather/status/1270336893717286912

As if 2020 just keeps getting better!

[AutoPenalti]

Just keeps getting better! Euro predicting a stronger then normal Bermuda high for Aug,Sept,Oct

https://twitter.com/webberweather/status/1270336893717286912

Don't know how much I believe this considering it's bias towards stronger ridging. We will see though.

[cycloneye]

Just keeps getting better! Euro predicting a stronger then normal Bermuda high for Aug,Sept,Oct

https://twitter.com/webberweather/status/1270336893717286912

In plain words, Caribbean cruisers may be a norm in 2020.

[weathaguyry]

This very positive AMO setting up has me extremely concerned, the current SST profile is starting to look increasingly similar to hyperactive years like 2005, 2010, and 2017...

Current 2020 Anomalies


2005 Anomalies


2010 Anomalies


2017 Anomalies

[Shell Mound]

Just keeps getting better! Euro predicting a stronger then normal Bermuda high for Aug,Sept,Oct

https://twitter.com/webberweather/status/1270336893717286912

Don't know how much I believe this considering it's bias towards stronger ridging. We will see though.

 https://twitter.com/catinsight/status/1270342562872786944



 https://twitter.com/catinsight/status/1270339970360901632



 https://twitter.com/WorldClimateSvc/status/1270344884298416128



 https://twitter.com/catinsight/status/1270360565974806529

[Shell Mound]

Further discussion:

 https://twitter.com/AndyHazelton/status/1270337919107182598



 https://twitter.com/webberweather/status/1270346572568694786



 https://twitter.com/webberweather/status/1270352624408199169



 https://twitter.com/cyclonicwx/status/1270353047512920064

[AutoPenalti]

Yikes, the healthy Hadley cell gives me Irma vibes.

[NDG]

Saharan dust has not made much progress to the west this season so far, I remember that by this time last year it was already raging across the Caribbean.

[JetFuel_SE]

Saharan dust has not made much progress to the west this season so far, I remember that by this time last year it was already raging across the Caribbean.

And this means what for the hurricane season?

[NDG]

Saharan dust has not made much progress to the west this season so far, I remember that by this time last year it was already raging across the Caribbean.

And this means what for the hurricane season?

Saharan dust all the way into the western Caribbean and GOM usually means strong trades & subsidence across the Atlantic MDR and puts a lid on development for a while.

[JetFuel_SE]

Saharan dust has not made much progress to the west this season so far, I remember that by this time last year it was already raging across the Caribbean.

And this means what for the hurricane season?

Saharan dust all the way into the western Caribbean and GOM usually means strong trades & subsidence across the Atlantic MDR and puts a lid on development for a while.

I may have worded that poorly, I meant something more like does this mean it's delayed or will we have very little SAL this year?

[USTropics]

And this means what for the hurricane season?

Saharan dust all the way into the western Caribbean and GOM usually means strong trades & subsidence across the Atlantic MDR and puts a lid on development for a while.

I may have worded that poorly, I meant something more like does this mean it's delayed or will we have very little SAL this year?

We'll have SAL outbreaks this year, especially as the ITCZ continues to lift north and increases the pressure gradient (common for peak SAL to be mid July - early August). The question remains, to what effect though? There is a correlation between an active/nonactive African Sahel monsoon season and an decrease/increase in SAL outbreaks. This is due to an active/nonactive monsoon pattern increasing/decreasing relative humidity, decreasing/increasing vertical wind shear, and thus decreasing/increasing dust load. We have had an active Sahel monsoon season so far:




This is a pretty cool 10 day forecast of SAL produced by NASA using GEOS-5 processing:

[youtube]https://youtu.be/cRNTU3JbpRw[/youtube]

Src - https://svs.gsfc.nasa.gov/4582

As far as ITCZ location this year, there has been a subtle movement towards the north in the past 10 days. The eastern branch is near normal location, however the western branch still remains slightly south to date:

[WeatherEmperor]

One thing I want to make sure I understand. In terms of steering, are we looking at more of a 1996/1998/1999 steering or more like a 2004/2017 steering pattern? The reason I ask is because in 1996/1998/1999, we had multiple cape verde hurricanes turn north into the Carolinas whereas in 2004/2017 there was stronger high pressure sending hurricanes into Florida. Which of these 2 patterns is more likely this season?


Sent from my iPhone using Tapatalk

[cycloneye]

 https://twitter.com/pppapin/status/1270523949886009344

[FireRat]

One thing I want to make sure I understand. In terms of steering, are we looking at more of a 1996/1998/1999 steering or more like a 2004/2017 steering pattern? The reason I ask is because in 1996/1998/1999, we had multiple cape verde hurricanes turn north into the Carolinas whereas in 2004/2017 there was stronger high pressure sending hurricanes into Florida. Which of these 2 patterns is more likely this season?


Sent from my iPhone using Tapatalk

Hi WeatherEmperor, if things pan out the way they look right now, especially with a STRONGER than normal Bermuda High, chances are that we will see more of a 2004/2017 steering pattern. A stronger Bermuda High would be less likely to weaken and allow hurricanes to go poleward ahead of the troughs. Instead, the high could remain firmly in control and send the storms more west, like into the Islands, Caribbean, FL and even the GOM. However the Carolinas would still be in play, because even with a strong Bermuda High, if it is far offshore, the storms could follow the edge of the High into SC/NC kind of like Hugo from 1989.

It really is tough to say what kind of steering we will have this far out, of course, but with the current indicators I'd go with a 2017 type steering pattern. This simply means that it would be unlikely to have most of the storms going out to sea, and instead hurtle toward land. Ultimately, for a Carolinas impact, or a FL/Carib impact, it will depend on both the strength and position of the Bermuda High, as well as the strength of any troughs by then.

[Shell Mound]

https://twitter.com/pppapin/status/1270523949886009344

This will probably result in some (short-term, that is) cooling of the MDR due to enhanced low-level divergence (trades) south of the PV axis.

[NDG]

Saharan dust all the way into the western Caribbean and GOM usually means strong trades & subsidence across the Atlantic MDR and puts a lid on development for a while.

I may have worded that poorly, I meant something more like does this mean it's delayed or will we have very little SAL this year?

We'll have SAL outbreaks this year, especially as the ITCZ continues to lift north and increases the pressure gradient (common for peak SAL to be mid July - early August). The question remains, to what effect though? There is a correlation between an active/nonactive African Sahel monsoon season and an decrease/increase in SAL outbreaks. This is due to an active/nonactive monsoon pattern increasing/decreasing relative humidity, decreasing/increasing vertical wind shear, and thus decreasing/increasing dust load. We have had an active Sahel monsoon season so far:

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


This is a pretty cool 10 day forecast of SAL produced by NASA using GEOS-5 processing:

https://youtu.be/cRNTU3JbpRw

Src - https://svs.gsfc.nasa.gov/4582

As far as ITCZ location this year, there has been a subtle movement towards the north in the past 10 days. The eastern branch is near normal location, however the western branch still remains slightly south to date:

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

https://i.imgur.com/jsD7vQ2.gif

Not only is the Saharan dessert a dust producing machine, China is one heck of a pollution maker

[cycloneye]

 https://twitter.com/AndyHazelton/status/1270712682451095560

[cycloneye]

 https://twitter.com/BenNollWeather/status/1270724902404845569

[cycloneye]

Yikes.

 https://twitter.com/webberweather/status/1270736950492889089