Hurricane season “paused” by Saharan dust from Africa
The Saharan Air Layer, also known as Saharan Dust, is made of sand, dirt, and other dust that is lifted into the atmosphere from the vast desert area that covers most of North Africa. This dust is carried in the African Waves which push westward into the Atlantic Ocean. These large plumes of dust are a very common occurrence in June and July.
The Saharan Air Layer is a well-mixed dry pocket of air that usually resides between 5,000 and 15,000 feet above sea level. Since one of the key ingredients for tropical cyclone development is a deep feed of moisture, Saharan Dust often acts to inhibit tropical development. Once a pocket a Saharan Dust begins moving westward over the Atlantic, it is relatively easy to track using infrared satellite products. This model combines the forecasted development and movement of the Saharan Air Layer with the GFS precipitation rate and pressure contours to depict the movement of the layer.
Skies all over Belize were ashen grey this morning - but don't blame forest fires or bad weather - it's a region wide phenomenon caused by what is known as the Saharan Air Layer.
That's a vast cloud of dust from the Sahara desert that's blanketing the Caribbean as it heads towards the US. Experts say the size and volume of dust hasn't been seen in half a century, and this one is being called the "Godzilla dust cloud". And while that may sound dramatic, it's with good reason. Air quality across most of the Caribbean reached record "hazardous" levels. We have seen numerous public health warnings from across the region and from Guatemala which warn people to stay indoors and use air filters if they go outside.
In Belize, there's an advisory from the MET service which says, quote, "The SAL is expected to continue producing hazy and dusty conditions over Belize through to next week, with a temporary break at the start of the weekend.
Persons with respiratory or heart disease, elderly persons or children should take precaution, stay hydrated, wear protective gear and avoid outdoor activities as much as possible and seek advice from your health care provider to stay adequately protected from the dusty and dry conditions." End quote
Today in Belmopan we asked the Deputy Director of Health Services about it:
Dr. Francis Murray, Deputy Director Of Health Services "This phenomenon is something that happens on a yearly basis. It's something that I believe affects mostly Caribbean countries it's the Sahara dust that is this phenomenon. It brings about the pollution that occurs within the air from various, I believe it comes from the African continent and drifts within the Caribbean to other countries. It also brings a lot of dust and other particles within the air that are not good for our health, and it primarily affects those who have lung conditions, who are asthmatics persons who have COPD, who have been smokers and have certain particular lung damage or have diseases of the lungs and hence that's part of why we particularly, and, using the facemasks helps those persons who are breathing the air that is not healthy and so we expect that we may have persons who have asthma actively having acute crisis within these days."
Cherisse Halsall: "We know that a lot of other Caribbean countries issued warnings, why is it that our government hasn't issued a similar warning?"
Dr. Francis Murray "I'll be honest with you. I only heard about the Sahara phenomenon last night. I have been attentive to other media and I believe that was something that we all were not aware of."
"Change in weather and climate may be a possible reason why this phenomenon is coming, reaching Belize. This is the first time I'm even hearing of it reaching this far."
So, again, the Sahara Air Layer is expected to continue producing hazy and dusty conditions over Belize through to next week, with a temporary break at the start of the weekend.
The much anticipated and forecasted Saharan dust from the deserts of Africa has arrived in Belize and its effects are clearly seen here on Ambergris Caye. The current Saharan dust episode is leading to the worst dust storm in the Caribbean in decades. From bright blue skies to a foggy gloom, the difference is obvious. CNN reported that this plume is dense enough to obscure the African coastline on satellite imagery and the forecast calls of the dust to be carried by trade winds straight from the Saharan Desert, across the Atlantic Ocean into the Caribbean and onwards to the Southeastern USA.
It is unusual that the dust is forecast to travel over central America and the US with such high concentrations, Claire Ryder, NERC Independent Research Fellow at the University of Reading, told CNN Weather. The dust layer is so thick you can see it on weather satellites. Astronauts have also gotten a good view of it from the international space station. The good news to it all is that the dust puts a pause on tropical storm activity in the region as the dry air removes humidity that hurricanes need to form.
Click here to read the rest of the article in the Ambergris Today
Re: The Saharan Air Layer, also known as Saharan Dust
#543139 06/24/2004:42 AM06/24/2004:42 AM
The National Meteorological Service of Belize has just issued an advisory on the Saharan Dust Plumes that has been blanketing the entire country since early this morning. The Met Service said that the outbreak of Saharan Air Layer ( SAL) which is unusually dense has been supporting hazy and dry conditions, decreased visibility, and reduced air quality over much of the Caribbean. It is expected that the Saharan Dust will continue to produce hazy and dusty conditions over Belize through next week, with a temporary break at the start of the weekend. The National Meteorological Service of Belize is advising that persons with respiratory or heart disease, elderly persons, or children should take precautions, stay hydrated, wear protective gear and avoid outdoor activities as much as possible and seek advice from your health care provider. Residents are also being advised to stay adequately protected from the dusty and dry conditions.
(Below is aerial footage of the conditions witnessed today near Punta Gorda Town, courtesy Edwin Varela.)
Saharan Air Layer (SAL) Advisory from the National Meteorological Service of Belize
An outbreak of Saharan Air Layer ( SAL) which is unusually dense has been supporting hazy and dry conditions, decreased visibility and reduced air quaility over much of the Caribbean.
The SAL is expected to continue producing hazy and dusty conditions over Belize through to next week, with a temporary break at the start of the weekend.
Persons with respiratory or heart disease, elderly persons or children should take precaution, stay hydrated, wear protective gear and avoid outdoor activities as much as possible and seek advice from your health care provider to stay adequately protected from the dusty and dry conditions.
Satellite imagery showing current SAL concentrations (23 June, 2020, 3 p.m.)
It's been two days of intense cloud cover and ashen grey skies. But it's not just Belize that's suffering. In fact, we're getting the least of it with other Caribbean nations acting as a buffer zone.
And while the ugly weather is certainly a buzzkill it's an extreme version of a phenomenon that's vital to the global ecosystem, and, it might even act as a brief respite from hurricanes.
This afternoon Cherisse Halsall headed to the MET office to find out what we can expect from the lingering dust cloud.
Every year tons of sand from the Sahara desert are kicked up by dust storms, blasted high into the sky, and carried across the Atlantic ocean on wind currents. And while it's a yearly event, the 2020 version is much heavier:
Ronald Gordon, Deputy Chief Meteorologist "The event that we're experiencing is much more intense than we have seen over the past several years. I've looked at records and it shows that this is probably a record year in terms of this particular event."
"So what happened in this particular case is that we had more intense than normal dust storms over the African continent and apart from that the easterly jet that would normally pick it up had diminished for a while so the dust was left there in the atmosphere and eventually when the jet did pick up back and those strong winds picked up and came across there was an intense amount, a lot of it."
And once that overload of dust reached the Caribbean it caused the intense cloud cover and "hazardous" air quality from which Caribbean nations are still reeling.
Reporter "We see our counterparts in the Caribbean really suffering through this, is there any reason that we would get a milder case of the dust storm than they do?"
Ronald Gordon, Deputy Chief Meteorologist "It is quite likely the case, they are closest to the source so they would really be receiving the brunt of it whereas on our in it would have already dissipated a lot by the time it gets here so we don't expect it to be as severe over us as it is in that area."
It's a sandstorm that coupled with COVID gives the pessimists among us a positively apocalyptic vision. But officials at the MET say it won't last very long.
Cherisse Halsall: "So what can we expect over the next few days until this dissipates?"
Ronald Gordon, Deputy Chief Meteorologist "It is forecast to continue throughout this week into next week, however, the models are indicating that the intensity will decrease by the weekend."
So the worst of it should be today, tomorrow, and by Friday we'll start seeing a decrease. It will linger around but not as intensely as we're experiencing it now.
Cherisse Halsall: "Is there any way this could contribute to staving off hurricanes this season?"
Ronald Gordon, Deputy Chief Meteorologist "For the time being.So we don't expect the dust to last throughout the hurricane season but at the moment with that amount of dust it will suppress hurricane activity."
"So for the time being within the tropical atlantic and the caribbean development of tropical systems is unlikely, however, I must caution that this is only a temporary situation and we are still forecasting the season to be above normal in terms of activity."
As you heard the worst of the weather will occur between today and tomorrow with the dust cloud dissipating and traveling stateside by the weekend.