Winter might have ended last week, but we're still reeling from its impact. This first article in a three-part series looks back on the snow events the Middletown-Odessa-Townsend area has experienced over the last four months and seeks to answer why we've had nearly weekly storms since the start of 2014.
Winter might have ended last week, but we’re still reeling from its impact. This first article in a three-part series looks back on the snow events the Middletown-Odessa-Townsend area has experienced over the last four months and seeks to answer why we’ve had nearly weekly storms since the start of 2014. Part 2 will offer a cost analysis, examining how much taxpayer money went into preparing and cleaning up after the winter storms. Part 3 will provide an overview of the effects on everyday life and ask, how are we preparing for next year?
See our print editions each Thursday for more graphics and data with this series.
There is no question this winter has been particularly difficult for the residents of the Middletown-Odessa-Townsend area.
According to official state weather data, Southern New Castle County has seen no less than 13 snowstorms this season that resulted in measurable accumulation, including one in all but three of the first 14 weeks of 2014. That includes the nearly one inch of snow the area received this week, four days after the start of spring.
As a result, the Appoquinimink School District has racked up 10 full days of emergency closures for snow and extreme cold since early December, as well as three late starts and one early dismissal, according to district officials.
“We’re going to end up with the second or third snowiest winter on record in Delaware, for sure,” Assistant State Climatologist Kevin Brinson said this week. “But I think what’s been most significant is the frequency of measureable snow events. When you combine that with the fact this has been the coldest January to March since the early ’80s, I think it’s safe to say this has been an abnormal winter in Delaware.”
WHAT IS TO BLAME?
Brinson said the multiple storms and cold weather we’ve experienced this winter are the result of two weather conditions working in unison.
The first is what climatologists refer to as a “negative phase” in the North Atlantic Oscillation or NAO.
“The NAO is a circulation pattern in the North Atlantic, which can dictate how warm or cold we are here in the northeastern U.S., particularly in winter months,” Brinson explained. “When this feature is in what we call a ‘negative phase,’ we tend to experience colder than normal temperatures. The NAO has been negative most of this winter, particularly since January.”
Brinson said the second contributing factor is a trough that allowed the polar vortex, a rotating mass of cold air over the Artic, to dip further south than usual. Because storms tend to form along the jet stream that defines the boundary of the polar vortex, that trough has helped lead to the number of snow events we’re experienced this winter.
“It’s not unprecedented, but it’s fairly rare to see it dip down into the northern United States, like it has this winter,” he said. “And the combination of that trough with the negative phase of the NAO is what we like to call the Siberian Express.”
Siberian Express certainly sounds like a fitting term for a winter that has dumped 38.1 inches of snow on M.O.T. area since Thanksgiving, which is well above the average annual snow fall of close to 18.5 inches.
This year’s recorded total snow accumulation for the M.O.T. area, which is measured in Blackbird, is one-tenth of an inch less than the winter of ’77-’78 and more than a foot less than the 51.1 inches recorded in the winter of ’57-’58 when 27 inches fell from March 19 to March 21, he said.
The snowiest winter on record in Delaware was in 2009-2010 when the First State saw a total of 72.8 inches, however no official count was recorded in the M.O.T. area, he said.
“That total was recorded at the New Castle County Airport, which is the National Weather Service’s closest observation station,” he said. “Middletown had an active cooperative observer from 1952 to 1988, although there were several years where data were missing or incomplete. Unfortunately, that station, which is based on volunteer observers, has not been active for about a decade.”
Perhaps surprisingly, this winter has actually been 0.5 degrees warmer than normal, mostly due to high temperatures in December, Brinson said.
This January and February, meanwhile, were the 25th coldest in Delaware in the last 120 years, with temperatures averaging 2.3 degrees Fahrenheit below normal.
IS THE SNOWY SEASON OVER?
“If I could tell you whether there would be any more snow coming our way, I’d be retired and living at a resort somewhere,” Brinson said.
He noted that Delaware has seen its fair share of spring snowstorms in early April, adding that another shot of winter weather isn’t out of the question.
“Looking at the latest models, I can tell you we aren’t going to go from frigid temperatures one day to short-sleeve weather the next, so it’s still a possibility,” he said. “But the good news is that with every passing day, we’re putting one more nail in this winter’s coffin.”