What causes African dust to disipate

[boca]

I know in August SAL less less of a feature but why is that?

[Derek Ortt]

The SAL is not dust.

The SAL is a very warm dry air mass, that is accompanied by a low-level easterly wind jet, which enhances westerly shear over the systems

[boca]

What causes it to ease up in August generally?

[Derek Ortt]

possibly the increased wave activity blocking the westward propagation of the SAL

[boca]

Thanks Derek

[hurricanetrack]

Gravity.

[SouthFloridawx]

The SAL is not dust.

The SAL is a very warm dry air mass, that is accompanied by a low-level easterly wind jet, which enhances westerly shear over the systems

So that has nothing to do with Saharan Dust?

[boca]

I thought it had to do with African dust too, see learned something new.

[senorpepr]

It's Saharan Air Layer... not the Saharan Dust Layer.

While it usually is associated with dust, the key is that it's dry air that kills the moisture needed for tropical disturbances. Furthermore, the shear associated with the easterly winds doesn't help the situation.

[hurricanetrack]

One would assume the SAL will abate in less than a month. It usually does and it even looks less impressive as of late anyway- not as far south with its dry, warm and stable influence.

Remember Dolly in 2002? The SAL rolled that storm plum up! I will never forget watching Dolly literally deflate with each passing satellite photo as the SAL was entrained within the circulation. Without SAL we would have some serious problems a lot more often, I would think.

[Jim Cantore]

One would assume the SAL will abate in less than a month. It usually does and it even looks less impressive as of late anyway- not as far south with its dry, warm and stable influence.

Remember Dolly in 2002? The SAL rolled that storm plum up! I will never forget watching Dolly literally deflate with each passing satellite photo as the SAL was entrained within the circulation. Without SAL we would have some serious problems a lot more often, I would think.

We'd have alot more Cape Verde storms thats for sure.

[windycity]

ya, SAL is our friend.

[Patrick99]

I don't know...I think that without a SAL, we'd have more storms, but a lot more of them would recurve, as they would form earlier and get caught up by that big low that typically splits the Atlantic.

With a SAL, if the waves aren't completely killed off, they re-fire closer in, develop, and make landfall.

[Windsurfer_NYC]

SAL is indeed dusty, as per the NHC FAQ page:

The Saharan Air Layer (SAL) is a mass of very dry, dusty air which forms over the Sahara Desert during the late spring, summer, and early fall and usually moves out over the tropical Atlantic Ocean. [...] It is not yet clear what effect the SAL's dust has on tropical cyclone intensity, though some studies have suggested that it too may have a negative impact on intensification.

[Aquawind]

SAL has dust but the effects are not clear.. Very dry air's effects are pretty obvious..negative on development. Everyone focuses on dust because we can see it in Sattelite and on our cars at times.