Philadelphians do have local options. Center City’s Asthma Center, which uses an automated system, posts counts between 6 and 7 a.m. Dvorin issues his counts, a 24-hour sample of what has landed in his Mount Laurel trap, on weekday afternoons.
The nearest certified counting station outside the region would be Springfield, N.J., which is just outside Newark. To the south and west, stations are better than 100 miles away from Philly.
Research is wanting on the ideal spacing between observation points, said Yolanda Clewlow, who runs the United Kingdom’s national pollen forecast service, but a “good correlation” in one study came up with an estimate of 24 miles. She said having more stations would have added value for verifying forecasts, a key to making them better.
Said researcher Lo: “Increasing the pollen observations would most definitely improve forecasting.”
The forecasts publicly available appear to be a mix of pollen climatology and predicted weather conditions, said Dvorin.
Not all the variables that drive pollen flight are understood. A sudden shower can ground flights in a hurry; an unexpectedly dry day can ambush a forecast.
The nation’s two largest commercial weather services, AccuWeather Inc. and the Weather Channel, post daily pollen outlooks. How useful are they?
On Friday, both were forecasting “high” ragweed counts. “That’s way, way off,” said Dvorin: Ragweed pollen won’t be showing up in traps for three months.
“Many apps, but no data,” says Buters.
Lo said that interest has been building in the allergy community to improve the observation network but that resources have been lacking. She said she has been looking at ways to use satellite data.
And automated counters, such as the one used by the Asthma Center, which the National Allergy Bureau has not yet approved, are gaining popularity, said Clewlow.
A consortium of 31 European nations is looking at ways to set standards and establish an automated network.
On this side of the pond, the short-term outlook for pollen forecasts isn’t sanguine, says Lo. “But considering that most of the pollen forecasts in this country are not very good, I think we can greatly improve on the current state of forecasting.”©2021 The Philadelphia Inquirer, LLC. Visit at inquirer.com. Distributed by Tribune Content Agency, LLC.