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

[JaxGator]

Imo, the SAL now doesn't look as bad as past years, though it is still dominate.

Saharan dust has made it all the way to Texas this year, I call that pretty bad for this year.

Humm..I didn't know that. I bet they had some cool sunsets but that's not what I meant. I meant in terms of density.

[TheStormExpert]

Imo, the SAL now doesn't look as bad as past years, though it is still dominate.

Saharan dust has made it all the way to Texas this year, I call that pretty bad for this year.

Humm..I didn't know that. I bet they had some cool sunsets but that's not what I meant. I meant in terms of density.

I know exactly what you are saying JaxGator, you do not see the deep pinks showing up in the SAL graphics like in previous seasons around this time of year, but it still is strong enough to put a damper on things.

[WPBWeather]

Actually, I should had said both articles are full of crap. Clearly during the past couple of years the Saharan dust has been on the increase.

Not to start an argument, but do you have any evidence or just an opinion of the levels of SAL?

.

I have as much evidence as both articles state. Yes, I agree that during the late 90s into the 2000s SAL did drop thus the much higher hurricane activity, but during the last few years a stronger Atlantic subtropical ridge was brought the SAL outbreaks back during this time of the year. Which makes sense, if indeed the AMO has now turned negative as per Dr Phil K these SAL outbreaks will be the norm once again as during the 80s and other periods when the AMO has been negative.

Thanks for providing some backup, but not sure Phil K has really stated anything specific on whether normal SAL outbreaks in July will persist or decline (as theyhave always done) in a few weeks.

[NDG]

 https://twitter.com/EricBlake12/status/755057599725219840

[tolakram]

The CIMSS Tropical Archive. View by date and select both overlays and images to compare maps over the years.

http://tropic.ssec.wisc.edu/archive/

[JaxGator]

Saharan dust has made it all the way to Texas this year, I call that pretty bad for this year.

Humm..I didn't know that. I bet they had some cool sunsets but that's not what I meant. I meant in terms of density.

I know exactly what you are saying JaxGator, you do not see the deep pinks showing up in the SAL graphics like in previous seasons around this time of year, but it still is strong enough to put a damper on things.

http://i66.tinypic.com/2ihxysx.jpg

That's true this time of year. Time will tell I guess.

[JaxGator]

Dang...that's a lot of fuel. Not saying we'll see so much doom. Just an idea of the potential out there.
http://wxmaps.org/pix/atlpot.png

[RL3AO]

Looks like the monsoon trough near 18 to 20N in Africa has weakened in the last day. Not familiar enough with the feature to know if this is temporary or a sign that a more standard ITCZ/trough is setting up around 10 to 15N.

[Dean4Storms]

Dang...that's a lot of fuel. Not saying we'll see so much doom. Just an idea of the potential out there.
http://wxmaps.org/pix/atlpot.png

Yea and check the TCHP for the Western Carib. and Straits of Florida!

http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/2016200at.jpg

[JaxGator]

Dang...that's a lot of fuel. Not saying we'll see so much doom. Just an idea of the potential out there.
http://wxmaps.org/pix/atlpot.png

Yea and check the TCHP for the Western Carib. and Straits of Florida!

http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/2016200at.jpg

Whoa. Every time I see that chart so far, it's stunning. It does a good job on showing how deep the heat is. West Carib and the Straits of Florida look very warm (as does the Gulf of Mexico and the Gulf Stream).

[tarheelprogrammer]

 https://twitter.com/philklotzbach/status/755404148833607680




Was a down year in the Atlantic outside of Andrew.

[tarheelprogrammer]

Probably no development up to the 3rd of August.

 https://twitter.com/MJVentrice/status/755412692723200000

[JaxGator]

That's my Birthday lol. I think studying the patterns and steering should be watched regardless but so far, convection looks good off Africa right now.

[SFLcane]

All I know is you better count your wishes things stay unfavorable with all that extremely impressive TCHP just waiting near home.

[tarheelprogrammer]

 https://twitter.com/airmarci/status/755142612445720576




Edit: Impressive wave off of Africa. Likely to meet SAL though.
http://www.ssd.noaa.gov/eumet/eatl/h5-loop-rb.html

[Ntxw]

All I know is you better count your wishes things stay unfavorable with all that extremely impressive TCHP just waiting near home.

TCHP in that area has been running extremely high the past several years. I don't think it is a precursor as much as we like to portray it as, in the record years it was much lower so it is not a needed commodity. Waters there by now and coming months always runs at 28C or greater is more than sufficient to support a cat 5 regardless. It just means that area has been experiencing dry and drought conditions with little up-welling. The more concerning feature would be if shear were to die down.

[SFLcane]

All I know is you better count your wishes things stay unfavorable with all that extremely impressive TCHP just waiting near home.

TCHP in that area has been running extremely high the past several years. I don't think it is a precursor as much as we like to portray it as, in the record years it was much lower so it is not a needed commodity. Waters there by now and coming months always runs at 28C or greater is more than sufficient to support a cat 5 regardless. It just means that area has been experiencing dry and drought conditions with little up-welling. The more concerning feature would be if shear were to die down.

Well the " potential " for explosive development is certainly there. Question is will there be anything to take advantage of it.

[Ntxw]

Imo, the SAL now doesn't look as bad as past years, though it is still dominate.

Saharan dust has made it all the way to Texas this year, I call that pretty bad for this year.

SAL is an interesting feature. Dust is just a symptom and a factor but no one really talks about the inversion that takes place. Maue did some clearing with posting about warm air above. SAL really is a layer of warm air (dust included) above cooler air below. On land we often call this a "temperature inversion." Warm moist air that rises and cools creates thunderstorms and convection when you heat the surface, but since it is already warm above no where to go essentially capped. This is more important than the actual dust itself. Which is why looking at higher pressures can give you a hint of warmer, drier mid level air

http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-85-3-353

[RL3AO]

Good point Ntxw. If it was just mid-level dry air from dust, you would still get convection due to a very moist tropical boundary layer. The inversion keeps atmosphere stable.

Probably a good comparison would be the elevated mixed layer in the US Plains. The dry elevated layer advected into the plains can greatly increase instability, but too much warm air can keep storms capped.

[Ntxw]

Good point Ntxw. If it was just mid-level dry air from dust, you would still get convection due to a very moist tropical boundary layer. The inversion keeps atmosphere stable.

Probably a good comparison would be the elevated mixed layer in the US Plains. The dry elevated layer advected into the plains can greatly increase instability, but too much warm air can keep storms capped.

Yes! Here in Texas we experience it in the spring quite often on a much smaller scale. Winds that blow off from the higher, warmer Mexican desert caps and busts severe weather outbreaks due to a similar warm air layer. I'm sure there's dust in that too just not as dusty as the air from the Sahara

So removing the dust is not going to simply fix the issue. You have to weaken that warm layer or sufficiently warm the marine layer below, I think the connection is to the pressures and Azores high. No coincidence SAL outbreaks are in tandem with the climo peak of the mid Atlantic upper ridge.