Day after day of cool, dry weather has made this spring one of the most glorious in recent memory - unless, of course, you're an allergy sufferer.
In that case, it's been one of the worst.
The sunny weather, great for baseball, picnics and strolls, is being blamed for the copious yellow pollen that's blanketed windshields and porches and irritated the eyes, noses and lungs of the allergy-prone.
"Every time I go to work in the garden, I've been deterred by the sneezing, wheezing and coughing," says Nancy Reiss, foiled in her efforts to landscape a new house in Towson.
"I sat on my porch for just five minutes and when I came inside, [my eyes] were filled with pus," said Bridgett Sheehey of Timonium, whose allergy drugs have proved useless this year.
"For me, it's the sneezing, watery eyes, tightness of chest and wheezing," says Charles Mulchi, a crop scientist at the University of Maryland, College Park.
"The other night, I had to get out an inhaler, which is rare," he said.
Daily fluctuations in pollen levels make it difficult to compare one year to the next. But Dr. Charles Bacon, a Towson allergist, said the tree pollen season - in full force over the past few weeks - is one of the worst in recent memory.
Allergists consider a pollen count of 20 grains per cubic meter of air sufficient to induce symptoms in an allergic person.
"A count of 100 is considered high, and we've approached 2,000 with the oak pollen," said Bacon.
Plant biologists and allergists agree that the sustained dry weather - only a trace of rain in the past three weeks - has allowed tree pollen to linger longer than usual and get blown from surface to surface.
Combination of factors
But several factors have conspired to produce this year's assault. Last year, an unusually wet summer equipped trees with bounteous reserves of water that produced full foliage and flowering this spring.
Hot weather several weeks ago encouraged trees to set out their flowers earlier than usual. The pleasant weather of the past few weeks - marked by cool nights and mild days - has also contributed to the problem.
"It's allowed these flowers to stay around a while," said Mulchi. "It's like putting flowers in a refrigerator."
Chance of showers
The prospect of rain early today and later this week raised hopes that the pollen will finally get washed into drains and streams, though forecasters said showers might be too brief to do much good.
"Friday night and Saturday morning, there's a chance of showers as a cold front comes through," said John Newkirk of the National Weather Service office in Sterling, Va. "But it won't be a long rain."
Dr. David Golden, a Johns Hopkins allergist who takes pollen counts on the roof of his office in Owings Mills, said tree pollen counts have been high but haven't broken records.
"It's just that the pollen won't go away," Golden said. "We've had breezy days that pick up everything on the ground and put it back in the air. The piddly rainfalls have been useless."
Pollen counts don't tell the whole story, he said. Over time, pollen grains break down into particles. Without a cleansing rain, these particles build up in the environment and cause symptoms, but don't show up in the daily reports because the machinery isn't designed to measure them.
Tree pollen, although high, is beginning to decline, said Golden. This week, the count has hovered around 200, compared with last week's 700 and the previous week's 1,500.
Tree pollen isn't more irritating than other allergens, said Golden. The problem is that trees produce huge quantities, exposing sufferers to an assault unmatched by other sources.
Every day a bad day
"People do seem to be having more trouble," said Golden. "A lot of my patients have some really bad days every year. This year, it's a real bear because every day is bad."
Some patients have seen their symptoms take on a darker characteristics.
"Last Friday, I saw people who had long histories of hay fever and this year for the first time ever have coughing asthma," Bacon said. Asthma, often triggered by allergens. is a more serious condition in which the airway becomes constricted.
At Lutherville Elementary School, nurse Robynn Segall has been busy putting cold compresses to the eyes of students suffering from itchy, watery eyes. "Teachers thought they had pink eye, but it's all been allergies," she said.
Sneeze for all seasons
The region is now entering the season for grass pollen, to which many people are sensitive. Levels, however, rarely exceed 20 grains, Golden said. Midsummer is the time for mold allergies, and late August ushers in ragweed season.
Though pollen levels vary from year to year, some researchers argue that global warming could produce rising pollen counts over time. In laboratory experiments, scientists growing ragweed have shown that pollen production rises when plants are given more carbon dioxide to breathe.
Increased carbon dioxide, brought about through the burning of fossil fuels, is a key feature of global warming.
"As the climate changes, we could expect to see changes in the duration of pollen and the amount of pollen produced," said Lewis Ziska, a researcher at the U.S. Department of Agriculture in Beltsville.