NOAA=SAL factor has supressed atlantic hurricane activity

[cycloneye]

http://www.noaanews.noaa.gov/stories2004/s2206.htm

Very interesting to read what this report from noaa says about the sal (SAHARAN AIR LAYER) and how in the past decades it has supressed the atlantic hurricane activity.Thanks to the sal the atlantic is not the most active basin in the world that distintion belongs to the WPAC.Imagine all of us dealing with many hurricanes like the WPAC has.

[Rainband]

Interesting. I wonder if The Sal will continue to have an impact this year and beyond. If it lessened we'd be in for it. But after all this is research and everything isn't set in stone. I find it very interesting research though. Thanks luis

[cycloneye]

Interesting. I wonder if The Sal will continue to have an impact this year and beyond. If it lessened we'd be in for it. But after all this is research and everything isn't set in stone. I find it very intersting research though. Thanks luis

We in the atlantic area haved dealed with very powerful hurricanes like Camille,Andrew,Allen,Gilbert,the 1928 hurricane,the 1935 keys,Hugo,Georges,Isabel and many more and those formed with less sal in the air so imagine if the sal never appears nomore what we can expect. But thankfully that sal factor has made the atlantic hurricane seasons less active even with the most active ones like in 1933(21),1995(19),2003(16),2001(15).The atlantic would have over 20 named systems every year without the sal around .

[Rainband]

We in the atlantic area haved dealed with very powerful hurricanes like Camille,Andrew,Allen,Gilbert,the 1928 hurricane,the 1935 keys,Hugo,Georges,Isabel and many more and those formed with less sal in the air so imagine if the sal never appears nomore what we can expect. But thankfully that sal factor has made the atlantic hurricane seasons less active even with the most active ones like in 1933(21),2003(16),2001(15).The atlantic would have over 20 named systems every year without the sal around .

I cant begin to think what would happen if the conditions limiting the frequency and intensity of Tropical systems disappeared

[Stormsfury]

That leads us to the Saharan Desert ... which definitely seems to have its purposes as one propogates westward .. it's believed that there was some role with the rain forests in South America, and also, with the SAL, the processes generally limit the Cape Verde season to just about 6 weeks on average ...

To imagine a season without the SAL (Saharan Desert), well ... IMHE (In My Honest Estimation), the average season would probably be about 15 storms a year vs. the average 10 currently right now. Remember, that region is dominated by wind shear most of the year with only a few months out of the year where conditions and SST's are conducive for development out there ...

SF

[Rainband]

That leads us to the Saharan Desert ... which definitely seems to have its purposes as one propogates westward .. it's believed that there was some role with the rain forests in South America, and also, with the SAL, the processes generally limit the Cape Verde season to just about 6 weeks on average ...

To imagine a season without the SAL (Saharan Desert), well ... IMHE (In My Honest Estimation), the average season would probably be about 15 storms a year vs. the average 10 currently right now. Remember, that region is dominated by wind shear most of the year with only a few months out of the year where conditions and SST's are conducive for development out there ...

SF

Thanks for your input Mike. Very informative as always

[Guest]

That darn SAL...Why I oughtta... #*!%@#*%!@#

[cycloneye]

That darn SAL...Why I oughtta... #*!%@#*%!@#

Imagine if the sal remains all the time in the atlantic how boring the seasons would be without tracking storms. There would be nothing that the NHC would track in the atlantic.

[Derek Ortt]

Of course the SAL will continue to affect hurricanes. Every single Atlantic TC has had SAL influences (Tropical Atlantic, that is). The question is whether or not the SAL overtakes a cyclone or becomes entrained into the center

[Guest]

We need to get a major campaign going to reforest the Sahara,that'll teach than darn SAL to tamper with our Atlantic storms.

Seriously though,I got to touch on something that Stormsfury brought up about the rain forests in South America.Has the deforestation that has occured there in the past few decades might in someway have robbed moisture from the tropical Atlantic, kind of enhancing the SAL conditions?
Because there are large parts of the rain forest that are now basically deserts because of deforestation.

[cycloneye]

SF that theory about the southamerica rain forest factor may be one of the keys to the more ammounts of sal in the atlantic and that angle must be explored much more by the scientists from noaa or other private companies.

[Derek Ortt]

How would the deforestation of S America influence the SAL at all? I see zero connection between the two. Not to ,mention, there is a SECOND equally important factor to the SAL in addition to the dry air. I'll wait until Jason Dunion's paper is released before commenting further on the matter as the SAL is more of his area of research (mine has been dry air in general, not specifically the SAL and specific correlations between the dryness and intensity change). Once that factor is more widely known, you'll realise that the deforestation is not a factor

[Guest]

How would the deforestation of S America influence the SAL at all? I see zero connection between the two. Not to ,mention, there is a SECOND equally important factor to the SAL in addition to the dry air. I'll wait until Jason Dunion's paper is released before commenting further on the matter as the SAL is more of his area of research (mine has been dry air in general, not specifically the SAL and specific correlations between the dryness and intensity change). Once that factor is more widely known, you'll realise that the deforestation is not a factor

What I meant & its not that hard to comprehend,was that large areas of South America that were once flourishing rain forests,humid & rain soaked on a daily basis are now a virtual desert.

Might that have ever so slightly changed the climate & introduced more relative dry air to the tropical Atlantic.Perhaps not the SAL but dry air in general.

Just a thought.. I am by no means an expert in these subjects

[Stormsfury]

IF the deforestation of the rain forests in South America eventually led to another desert across that region, then the change would be for South American dust to be entrained into the EPAC regions, and in turn affect EPAC and maybe, WPAC storms ... but that's very, very hypothetical ...

As for the dust in the South American Rain Forests, that's not hypothetical ... scientists found Saharan dust buried deep within the rainforests (and part of this could tie in with the splitting of the supercontinent Pangaea)...and part of it ties in with Saharan Dust mixing into the torrential rains that fall...

I'm still searching for more information on that.

SF

[weatherjan]

Dr Frank Marks, the current director of the Hurricane Research Div (HRD) in Miami, wrote his PhD dissertation on the subject of the Saharan Air Layer (SAL). A recent article focusing on the SAL, authored by Dunion and Velden, appears in a recent issue of the Bulletin of the American Meteorological Society (BAMS). An abstract of this article can be found at this link: http://ams.allenpress.com/amsonline/?re ... &page=0353

Jan S
Oneida, NY

[SacrydDreamz]

IF the deforestation of the rain forests in South America eventually led to another desert across that region, then the change would be for South American dust to be entrained into the EPAC regions, and in turn affect EPAC and maybe, WPAC storms ... but that's very, very hypothetical ...

As for the dust in the South American Rain Forests, that's not hypothetical ... scientists found Saharan dust buried deep within the rainforests (and part of this could tie in with the splitting of the supercontinent Pangaea)...and part of it ties in with Saharan Dust mixing into the torrential rains that fall...

I'm still searching for more information on that.

SF

BINGO!

[Steve H.]

Well, I know one thing (at least), that since they starting building like crazy in central Florida and the Orlando area, my afternoon summertime showers just aren't happening like they used to. When I moved to east central Florida 18 years ago, you could set your watch by looking at when the rain came, at about 4:20 everyday Not so anymore. All the "jungle" vegetation is/has been replaced by concrete I'm not the only one who's been noticing this by any means, been in the papers. On the other hand, we got to remember that the earth is mostly water, so there certainly isn't any lack of that. It may be more closely connected to the convective currents and there associated wind patterns that are changing, and these may be a result of the sea surface temp changes/anomalies we've been seeing. Just a guess, mind you, as we have no long term data to substantiate any of this. Interesting though. With TCs hitting Brazil wwe know this........the times they are a changing.........again

[AussieMark]

I think from memory a decent sized SAL set in after Isabel last year and ripped apart numerous decent looking tropical waves.

Last year very well could of been more active than it was.

[ColdFront77]

Well, I know one thing (at least), that since they starting building like crazy in central Florida and the Orlando area, my afternoon summertime showers just aren't happening like they used to. When I moved to east central Florida 18 years ago, you could set your watch by looking at when the rain came, at about 4:20 everyday Not so anymore. All the "jungle" vegetation is/has been replaced by concrete I'm not the only one who's been noticing this by any means, been in the papers. On the other hand, we got to remember that the earth is mostly water, so there certainly isn't any lack of that. It may be more closely connected to the convective currents and there associated wind patterns that are changing, and these may be a result of the sea surface temp changes/anomalies we've been seeing. Just a guess, mind you, as we have no long term data to substantiate any of this. Interesting though. With TCs hitting Brazil wwe know this........the times they are a changing.........again

Where I live (The Villages, in central Florida) has grown tremendously in the last few years and is expected to continue to do so in the next 10 to 15 years.

The afternoon and evening thunderstorms during the summertime have been occurring just about every day here in central Florida (1 1/2 hours northwest of Orlando).