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SBEP Director: Good news, bad news in red tide forecast

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Director’s Note: Outlook for red tide?

From Sarasota Bay Estuary Program Director Dave Tomasko

A bit of good news/bad news about the likelihood of red tides in the coming months. First, let’s do the “bad” news. If you’ve been watching the news about weather out west, it is incredibly hot and dry out there lately. Also, if you’ve been watching sunsets over the past few weeks (like I do) you’ve seen some beautiful red and orange ones off to the west. The old guidance of “red sky at night, sailors delight” reflects the fact that red skies indicate more particles in the air, which preferentially scatter blue light.

These atmospheric particles are typically associated with descending air masses, which are also high-pressure systems. These high-pressure systems to the west indicate low pressure systems to the east, since high and low pressure systems typically pair. Since our weather mostly moves west to east and since high pressure systems are less scary to sailors then low-pressure systems, that’s why a sailor loves seeing red sunsets. Same reason for “red sky at morning, sailor takes warning” – since that indicates a high to the east, and a paired low-pressure system to the west (where our weather comes from). And sailors hate low pressure systems, because they are associated with tropical events, for one thing. This long-standing guidance is also noted in the Bible - Matthew 16:2-3.

Unfortunately, our current atmospheric high is also loaded with dust from the Saharan Desert, according to NASA – A Burst of Saharan Dust (nasa.gov). Check any websites on Texas weather and you’ll see they are quite concerned about that dust fallout – not good if you have asthma or COPD. But also, Saharan dust contains lots of iron. I took the photo below five years ago on a flight from Jeddah to Riyadh, in Saudi Arabia. It’s the Arabian Desert, not Saharan, but similar and at the same latitude. All that pink to red tint in that photo is from the high iron content of the sand and dust. As these events bring Saharan Dust across to Texas and the southwest, they not only make it hot and dusty weather for folks out west, but these events also add a lot of iron to the Gulf of Mexico.