Despite this past weekend's chill, a freakishly warm February across much of the U.S. has caused flowers, trees and plants to bloom weeks early and also threatens to bring a whopper of an allergy season.
How early? In a large chunk of the U.S. from Texas to New York, spring arrived two to three weeks earlier than normal, according to data from the U.S. Geological Survey and the National Phenology Network. In Washington, D.C., spring was 22 days early.
The peak bloom of the iconic cherry blossom trees in Washington could be one of the earliest ever, perhaps as early as March 14-17, according to the National Park Service. The record earliest peak bloom, when 70% of the blossoms are open, was on March 15, 1990.
"Spring is springing. Flowering trees are starting to do their thing," National Mall and Memorial Parks Superintendent Gay Vietzke said last week. The weekend chill shouldn't affect the cherry blossoms, the Capital Weather Gang's Kevin Ambrose told the Weather Channel on Sunday. The cold, however, did kill many magnolia blooms this weekend, he said.
In Memphis, many of the city's trees and plants are about a month ahead of schedule, Rick Pudwell, director of horticulture at Memphis Botanic Garden, said recently.
And in New Jersey, the recent warmth has caused tree and shrub buds to start swelling early. However, any extended cold could still affect early-spring flowering trees, said Bill Zipse, regional forester for the state forest service.
Changes in the timing of spring can affect human health, bringing early-season disease-carriers such as ticks and mosquitoes, and an earlier, longer and more vigorous pollen season, the National Phenology Network warned. While a longer growing season can result in increased yields for some crops, it is risky because of the higher likelihood of plant damage caused by late frosts or summer drought.
Indeed, for allergy sufferers, the springlike warmth should trigger symptoms sooner than normal. “Much of the Southeast through the East Coast is looking to have increased levels of pollen this year due to the mild end of winter,” AccuWeather meteorologist Alan Reppert said.
A high concentration of tree pollen has already been reported in several cities in the Southeast, according to the American Academy of Allergy, Asthma and Immunology's National Allergy Bureau.
Reppert said the warm air that arrived in late February provided early growing opportunities for plants, which are causing the pollen season to be about 10-20 days ahead of normal in some areas.
The return of colder air might help mitigate conditions, he said, but it likely won't be enough to slow the spread of pollen fully.
Other potential impacts of the weird warmth include the early re-emergence of disease-carrying parasites and insects, such as ticks, fleas and mosquitoes,the (Cleveland) Plain Dealer reported.
The lack of cold this winter means that "many of our invasive pests that would be harmed if we had a normal winter will survive better," University of Maryland entomologist Michael Raupp told the Diamondback newspaper.
Warmer-than-average temperatures are forecast for much of the next two weeks, according to a forecast from the Climate Prediction Center released Saturday.
As for February, the month was truly one for the record books: Though final national numbers won't be available from federal scientists for a couple of days, what is known is that more than 270 cities and towns across the nation had their warmest February on record, according to the Weather Channel.
This year's unusual warmth is part of long-term trend due to man-made global warming: "We’ve known for over a decade now that climate change is variably advancing the onset of spring across the United States," the National Phenology Network said on its website.
This phenomenon has been documented around the world and is informally dubbed “season creep," Climate Nexus, a communication group, reports.
Contributing: Doug Stanglin, USA TODAY; Tom Charlier, The Commercial Appeal; James M. O'Neill, NorthJersey.com; The Associated Press