Seasonal Indicators (Beyond Day 16): Instability / SST's / MSLP / Steering / Sal

[tarheelprogrammer]

SAL is really starting to fade away in the MDR

http://tropic.ssec.wisc.edu/real-time/sal/splitE/movies/splitE5.html

[tolakram]

I don't want to get too excited about this ...

But if this actually can manage to cross the normal line I think it will be the first time in years during the hurricane season.



We had discussed in the past if this was a leading or trailing indicator ... I think it's trailing. The waves hitting the deep tropics and mixing out the SAL seem to be what is raising this number. Thoughts?

[ninel conde]

I don't want to get too excited about this ...

But if this actually can manage to cross the normal line I think it will be the first time in years during the hurricane season.



We had discussed in the past if this was a leading or trailing indicator ... I think it's trailing. The waves hitting the deep tropics and mixing out the SAL seem to be what is raising this number. Thoughts?

It seems to spike up and down alot. I would wait and see if it can stay up for awhile.

[tolakram]

It seems to spike up and down alot. I would wait and see if it can stay up for awhile.

Sorry, what am I waiting for? If it's trailing and the waves out there now dry up then this indicator will fall in my opinion. If the waves develop then the indicator will stay elevated.

All this time and I never thought to look at the EPAC instability. The current way to measure seems to always indicate below normal conditions. EPAC didn't seem to have any issues. Makes me wonder if we really are below normal or if the scale/normal line is off.

[ninel conde]

It seems to spike up and down alot. I would wait and see if it can stay up for awhile.

Sorry, what am I waiting for? If it's trailing and the waves out there now dry up then this indicator will fall in my opinion. If the waves develop then the indicator will stay elevated.

All this time and I never thought to look at the EPAC instability. The current way to measure seems to always indicate below normal conditions. EPAC didn't seem to have any issues. Makes me wonder if we really are below normal or if the scale/normal line is off.

There is lots of below in the eastpac but also it spikes above normal from time to time. I dont think there is any doubt instability is below normal in the tropical atl simply from the absence of convection. If some waves can make it across with convection we can see if the graph responds. As far as whether the scale is off or not i have no idea. it would be nice to see a graph of years where the MDR was convectively active to compare to now.

[tolakram]

There is lots of below in the eastpac but also it spikes above normal from time to time. I dont think there is any doubt instability is below normal in the tropical atl simply from the absence of convection. If some waves can make it across with convection we can see if the graph responds. As far as whether the scale is off or not i have no idea. it would be nice to see a graph of years where the MDR was convectively active to compare to now.

We have those, I've linked before, but the scale has been changed for the last few years. It's as expected with active years showing above normal instability.

I think by any objective measure, especially since the EPAC has had a hyperactive record setting July, this indicator by itself is pretty meaningless. EPAC in July was below normal for all but a few days.

[TheStormExpert]

 https://twitter.com/michaelrlowry/status/758396138135359488

[tarheelprogrammer]

Great video by Mark Sudduth.

https://www.youtube.com/watch?v=BO05j51O96w

[InRRwetrust]

Great video by Mark Sudduth.

https://www.youtube.com/watch?v=BO05j51O96w

Great link, much appreciated
Huge extra energy potential indeed!
I assume you folk are in for a few itchy months? :/

[NDG]

Thanks to a persistent -NAO over the eastern Atlantic the MDR has warmed up nicely over the past few days. This is definitely not 2015's numbers and it does not look like a -AMO.

[JaxGator]

For now, no SAL coming off Africa.
http://imagizer.imageshack.us/v2/1024x7 ... Ugb2rS.jpg

[tolakram]

With a couple of active waves the instability has jumped to near normal for the deep tropics.

[ninel conde]

For now, no SAL coming off Africa.
http://imagizer.imageshack.us/v2/1024x7 ... Ugb2rS.jpg

I dont think SAL will be a big issue any longer as the atl ridge should get beaten down

[Hammy]

With a couple of active waves the instability has jumped to near normal for the deep tropics.

One thing I've wondered regarding this, is low instability a cause of a quiet Atlantic, or is it the result of it?

[gatorcane]

SSTs are running warmer than normal across just about the entire Caribbean and SW Atlantic:

[WeatherEmperor]

With a couple of active waves the instability has jumped to near normal for the deep tropics.

One thing I've wondered regarding this, is low instability a cause of a quiet Atlantic, or is it the result of it?

Fantastic question. I am really wanting to know the answer to this as well.

[AJC3]

With a couple of active waves the instability has jumped to near normal for the deep tropics.

One thing I've wondered regarding this, is low instability a cause of a quiet Atlantic, or is it the result of it?

Fantastic question. I am really wanting to know the answer to this as well.

I'd say it's mostly "cause", with a wee bit of "result" thrown in.

Incipient disturbances (AEWs) emanating from Africa either do or don't develop, depending upon the environment (thermodynamic, shear, SST) that they find themselves traversing. On the other hand, a strong/active AEJ and AEW train results in numerous disturbances (as well as attendant SAL outbreaks) which modify the ambient thermodynamic environment, for better or worse.

[TheStormExpert]

Busy August in the Atlantic possible, September still up in the air.

 https://twitter.com/ericblake12/status/759729452876128256

[NDG]

, Yeap Perhaps a sign that the Atlantic Basin will be getting very active by the middle to late August if the GFS is correct, which coincides with CFSv2 forecasting below average MSLPs across the Atlantic basin for next month.

[stormwise]

wow those runs looking mean,eye opener for those who wrote off the season.