Washington-PostGoodbye, polar vortex. Hello, pollen vortex.

It turns out this brutally cold, miserably long, snowfest of a winter did more than wreak havoc on the bundled Mid-Atlantic masses. It also caused elms, cedars and other trees that typically flower early in the year to hold off for warmer weather.

Now, with more springlike days finally in the forecast, those trees are poised to pollinate alongside oaks, cottonwoods and pines, as well as some grasses. The result could mean a perfect storm of pollen in coming days — and an especially miserable stretch for allergy sufferers.

“Grab your Kleenex,” said Susan Kosisky, chief microbiologist at the U.S. Army’s Centralized Allergen Extract Lab. “It’s coming.”

Every day on the roof of Kosisky’s lab in Silver Spring, two small greased rods spin through the air, collecting pollen particles. She said that over the past 15 years, the average daily measurement for the first week in April is about 353 grains per cubic meter of air. That figure can spike to more than 4,000 at the peak of the allergy season.

This week’s most recent reading: 109 grains per cubic meter.

That’s good news for many allergy sufferers at the moment. But it suggests a tidal wave of pent-up pollen could be headed our way as the area heads toward the height of allergy season later this month.

“As soon as we get four to five days of sunshine in a row, we’re going to see the buds on the trees explode and people are going to be really suffering,” said Clifford Basset, medical director of Allergy & Asthma Care of New York.

Soon, the cars and sidewalks that have remained snow covered through much of the winter (and spring) could be coated in a familiar yellow-green dust. And many people will be trading in winter coats for runny noses, itchy eyes and uncontrollable sneezing.

The danger of a shorter but more intense allergy season, specialists say, is that it could overwhelm immune systems, triggering potentially serious health issues.

Experts say people with allergies can take measures to lessen their contact with pollen, including using central air conditioning rather than opening windows, wearing sunglasses when outdoors and washing their hands frequently. In addition, doctors say patients who know they have spring allergies can begin taking antihistamines before the worst of the season arrives.