pollen vortex
n. High levels of spring pollen created when temperatures rise quickly following an extremely cold winter.
Examples
2014
And — for allergy sufferers — here’s the good news: Second Genome has appeared to isolate a link between allergic diseases and the bacteria living in your gut. What it means is that you may one day buy a drug from Johnson & Johnson that injects bacteria into your body to prevent allergies or minimize allergic reactions. Instead of buying an over-the-counter antihistamine drug during the peak of the pollen vortex, you‘d buy a bacterial therapy pioneered by a microbiome company.
—Dominic Basulto, “The secret to treating your allergies may lie in your stomach,” The Washington Post, April 17, 2014
2014
And for that, you can blame the polar vortex—the extreme cold system that repeatedly hovered over much of the United States this year—along with the rest of this winter's brutal weather. Those cold snaps helped spawn a spring allergy season so intense that it already has its own headline-ready nickname: the "pollen vortex."
—Molly Redden, “A Brutal Allergy Season Is Ahead. Blame the Polar Vortex.,” Mother Jones, April 15, 2014
2014 (earliest)
Polar Vortex to Pollen Vortex? Experts say Spring allergies could be terrible due to record snow.
—Mark Santia, “Polar Vortex to Pollen Vortex…,” Twitter, March 18, 2014