If you don’t like the weather just wait a minute, as the saying goes. State Climatologist Dr. David Legates is predicting that cooler temperatures — and at least a couple nor’easters — will soon remind Delawareans what they’ve been missing, after an exceptionally mild January (nearly 9 degrees above the monthly average).
“We did have warmer-than-average temperatures over a prolonged period, but December was colder than the norm (by about 2 degrees),” Legates pointed out. November was also slightly colder than average, and Delaware received a little more snowfall than normal that month, he added.
(Last weekend’s snowfall, about 4 inches in Georgetown, brought the area close to the monthly average for Februaries in Sussex County, so any new snow will probably bump Sussex into an above-average February.)
Additionally, Legates said regional highs and lows typically balance out, following a wavelike pattern. As a case in point, Alaska also approached all-time records last month – on the low side.
“And whenever Alaska’s having record highs, we’re freezing,” Legates noted.
Temperatures bottomed out somewhere in the late 1970s — staff at the University of Delaware’s Carvel Research and Education Center remember the bays having frozen over in 1977, and Legates remembers Lake Forest schools closing for a solid week.
Delaware hit its single-day record highs about 30 years earlier, in 1950 (75 degrees on Jan. 26), and Legates said climatologists are increasingly lending credence to the idea that certain weather patterns followed 30-year cycles. “You see the same thing with hurricanes,” he noted.
Legates said he receives most of his calls from people interested about hurricanes — but he said direct landfall just isn’t an issue in Delaware. “The geography is such that if it doesn’t hit Cape Hatteras (N.C.), it hits Long Island (N.Y.),” he pointed out.
Nor’easters are of much greater concern, Legates said, and he predicted at least two nor’easters would impact Delaware this winter. Last year was relatively quiet for nor’easter activity, with a couple storms tearing past the area at top speed but none stalling long enough to cause significant damage.
According to Legates, nor’easters result when warm, wet air crossing the mainland from the Gulf Coast intersects cold air dipping southward from the Arctic. The Earth’s rotation grips the low pressure system and spins the storm counterclockwise – bringing the wind around and out of the northeast.
He noted another variant, on that caused the 2003 Valentine’s Day storm (more than 28 inches of snow in Lewes). That year, a low pressure system formed off the coast of Norfolk, Va., moved southwestward to the Gulf, picked up warm, moist air and wandered back.
Tropical storms do brush by on occasion, but they are typically moving along at a good clip by the time they reach this area, Legates pointed out. But nor’easters sometimes stall, compounding the damage caused by heavy rains, wind and flooding.
As a worst-case scenario, one storm blowing out of the Gulf Coast meets up with another storm moving up the coast from Cape Hatteras, he said.]
According to Legates, the Indian River Inlet has a tendency to compound problems, due to its size.
“It’s a small inlet, and whenever these storms dump a lot of water into the Inland Bays, it just can’t get out,” Legates noted. This traditionally leads to increased problems with flooding all around the Inland Bays, he said.
Legates and colleagues are working to install a continuous series of monitoring stations along the coast, expanding the DEOS system. There are two local DEOS stations, in the Bethany area, and tons of additional data at www.deos.udel.edu on the Internet. The State Climatologist’s Web site (www.udel.edu/leathers) carries current forecasts and historical data. Additional information on monthly snowfall comes from the National Oceanic and Atmospheric Administration (NOAA) Web site, www.ncdc.noaa.gov/ussc.