Friday, August 2, 2013

Saharan Air Layer Puts Hold on Tropical Activity

Dry air has moved off of Africa as part of the Saharan Air Layer, resulting in lowered chances for tropical activity over the next several days.

In recent days, an intense layer of dry air has shifted west from Northern Africa, resulting in not only stunning satellite images, but also a decreased chance for tropical development in the eastern Atlantic and for tropical waves coming off of Africa. I anticipate that we should see this outbreak of dry air dissipating over the next week or two, which should allow tropical waves over Africa a better chance for tropical development.

Model guidance indicates chances of tropical development will increase after the 5 day mark from today, which is roughly the time we will see the dry air moving further through the Atlantic and dissipating in the process.



Eric (weather advance) said...

Hi Andrew, I figured you would like to see this, here's my newest post & yes, it's a very long post as usual, full of very good information & analysis.

Andrew said...

Excellent read, Eric, as always. Your analog package is definitely doing well, and hopefully it works out favorably come winter. I did an analysis of roughly a dozen variables on my two winter analog years (1951-1952 and 1962-1963), and found that the latter year clearly outperformed the 1951-1952 winter in that analysis. The fact that 62-63 is a front runner is good- that winter featured a frigid Great Lakes/Midwest and a stratosphere with a very suppressed polar vortex. On the other hand, though, both of my analog years had a negative QBO during the winter (other than that QBO difference, the 62-63 analog had a perfect record for matching up with this summer's current conditions on those dozen variables).