As look as we have Sal no development

[boca]

According to Derek he posted that as look as SAL is present these waves won't develop and he knows this type of senario well.

[robjay]

SAL stands for what?
Why does SAL prevent tropical development?

[cinlfla]

According to Derek he posted that as look as SAL is present these waves won't develop and he knows this type of senario well.

Then whats the point in even putting up an invest and doing model plots if nothing will come out of these waves? Seems like a waste of time if Sal puts a halt to anything developing.

[Stormcenter]

According to Derek he posted that as look as SAL is present these waves won't develop and he knows this type of senario well.

Then whats the point in even putting up an invest and doing model plots if nothing will come out of these waves? Seems like a waste of time if Sal puts a halt to anything developing.

Thank you. I think I'll stick with what the NHC has to say. If they say there is a possibility then that's what I will believe. No offense to the Mets on this board but hey these guys at the NHC are in the positions they are in because they are the best.

[x-y-no]

The area of dry air ahead of Invest-92 appears to be eroding. Compare the latest analysis:




with what it was like 24 hours earlier:



At this rate, it seems to me that conditions will be OK for development in another day or at most two.

I freely admit that Derek knows far, far more than I do on this topic, however.

Jan

[vbhoutex]

The maps posted do indicate that IMO the SAL is indeed weakening and/or moving a little N also. With that in mind I think that the new invests may have a better chance at development now than they did 24 hours ago when it was obvious that the SAL was very prevalent in that area.

[cinlfla]

When they put up an invest I would assume its because of the possibilities. I personally listen to them because I figure they are the experts but I don't recall them saying anything about the Sal hindering development at this time. I may be wrong dunno, but my Question was never answered, if no develpment then why the invest? Oh I just wanted to mention I listen to them not for what I want to hear but to get information for tracking purposes because I do enjoy Hurricane season.

[bvigal]

for those still asking: SAL = Saharan Air Layer = African dust

Hmmm, well I'd really like to discuss this issue, arugments aside, so I can learn something... OK guys?

I had a question about the SAL map, it looks as if Pacific is all dust, too. Is that correct, or can other conditions cause the red color, i.e. is all red SAL??? Or can I look at that map and incorrectly assume something is dust that really isn't?

And let's talk about layers of the atmosphere. Here, below 6,000ft. we are seeing clearing. I know that because every day I look my windows and there is an island, St. Thomas, which takes up 1/3 of my horizon view!! Today I can see it again.

But, how much dust is there as we go up from sea level? How low must dust be, what layer, to put the lid on development? To illustrate, with a wild extreme, does dust at 50,000ft. clamp development? (I know that answer )

Finally, let's talk about distance. A broad circulation like 92L can certainly pull in dust from hundreds of miles away, right? Can anyone show us a static visible sat pic this morning and indicate where dust is traveling and at what levels?

Thanks for any and all attempts to increase my knowledge!

By the way, if anyone is interested in health/environment issues related to dust, here are a few interesting links:

http://earthobservatory.nasa.gov/Study/Dust/
http://coastal.er.usgs.gov/african_dust/

[Derek Ortt]

first one still seems to be over taken.

the one behind it could have some slow and milited development, but the chances are that both could develop once they clear 60W, or move north of 20N, where the SAL grip is less. A good example of that is Andrew

[Derek Ortt]

also,

I am going to start making precipitable water maps again in the near future of the tropical Atlantic, as I have done the past 2 years. Likely, this year I will use TRMM data, unlike years passed where I have used SSM/I as TRMM has slightly better coverage of the tropical regions

[Stormcenter]

When they put up an invest I would assume its because of the possibilities. I personally listen to them because I figure they are the experts but I don't recall them saying anything about the Sal hindering development at this time. I may be wrong dunno, but my Question was never answered, if no develpment then why the invest? Oh I just wanted to mention I listen to them not for what I want to hear but to get information for tracking purposes because I do enjoy Hurricane season.

That's is exactly how I feel and if it offended anyone well I'm sorry. If the NHC felt it was going to prevent development or was an issue then they would state it in the their outlooks. I have nothing else to say concerning SAL.

[x-y-no]

first one still seems to be over taken.

the one behind it could have some slow and milited development, but the chances are that both could develop once they clear 60W, or move north of 20N, where the SAL grip is less. A good example of that is Andrew

OK, but that's a little different than what I understood you to be saying in the other thread, where you said they're "done."

I absolutely agree there's no prospect of development until these systems get out of this environment. It just seems to me that may happen for the lead system within the next two days, and for the following system maybe a day later.

Jan

[Derek Ortt]

the second one ahs the better chance. The first one looks as if it is under the sal. I do not recall a storm that was this entwined with the SAL to recover

[bvigal]

Derek, can you answer any of my questions?

for those still asking: SAL = Saharan Air Layer = African dust

Hmmm, well I'd really like to discuss this issue, arugments aside, so I can learn something... OK guys?

I had a question about the SAL map, it looks as if Pacific is all dust, too. Is that correct, or can other conditions cause the red color, i.e. is all red SAL??? Or can I look at that map and incorrectly assume something is dust that really isn't?

And let's talk about layers of the atmosphere. Here, below 6,000ft. we are seeing clearing. I know that because every day I look my windows and there is an island, St. Thomas, which takes up 1/3 of my horizon view!! Today I can see it again.

But, how much dust is there as we go up from sea level? How low must dust be, what layer, to put the lid on development? To illustrate, with a wild extreme, does dust at 50,000ft. clamp development? (I know that answer )

Finally, let's talk about distance. A broad circulation like 92L can certainly pull in dust from hundreds of miles away, right? Can anyone show us a static visible sat pic this morning and indicate where dust is traveling and at what levels?

Thanks for any and all attempts to increase my knowledge!

By the way, if anyone is interested in health/environment issues related to dust, here are a few interesting links:

http://earthobservatory.nasa.gov/Study/Dust/
http://coastal.er.usgs.gov/african_dust/

[x-y-no]

the second one ahs the better chance. The first one looks as if it is under the sal. I do not recall a storm that was this entwined with the SAL to recover

It does look like the dry air is completely over the center. It sure would be extraordinary for this system to recover from that.

[Derek Ortt]

on that map, all dry air shows up the same as it is a combo product with 2 different satellite wavelengths.

From looking at GPS dropsondes, the SAL is between 2 and 5KM above the surface. You likely won't experience much drier conditions at the surface

yes, dust can be entrained into the center from far away. However, in a peper I am hoping to soon have published, I have found that this seems to happen typially in conjunction with shear

[bvigal]

on that map, all dry air shows up the same as it is a combo product with 2 different satellite wavelengths.

From looking at GPS dropsondes, the SAL is between 2 and 5KM above the surface. You likely won't experience much drier conditions at the surface

yes, dust can be entrained into the center from far away. However, in a peper I am hoping to soon have published, I have found that this seems to happen typially in conjunction with shear

Thank you!

[mf_dolphin]

ADMIN Note: Step away from the keyboard if your blood pressure is going up. I've sent a couple of PM's already. Let's get back on track before people get a vacation.......

[Derek Ortt]

I was a bit out of line with some of the statements I made, and I regret making those statements

[recmod]

first one still seems to be over taken.

the one behind it could have some slow and milited development, but the chances are that both could develop once they clear 60W, or move north of 20N, where the SAL grip is less. A good example of that is Andrew

Looking at those images of the SAL posted above, I'd say that the area above 20N has a much stronger SAL than the tropical regions to the south (the orange dust layer is mostly confined above 20N)...unless I am reading those maps completely wrong.

--Lou