Numbers offer depth to winter storm coverage

DOVER — Through the winter storm last weekend, it seemed that our DelawareStateNews.net readers were most eager to see snow totals. The source we used to provide regular updates was the Delaware Environmental Observing System. At times, the inch counts were going up rather quickly. Each hour offered another opportunity to gauge just how wicked a storm we were experiencing. “It was an interesting storm in that we had a lot of snow coming down in these sort of squalls,” said the University of Delaware’s Kevin Brinson, director of the system. “We had lots of banding, heavier areas that would pass through and they would drop an inch to 2 inches in a one- or two-hour span,” he said. “Then you would go through a lull and then another band would come through.”

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Across Delaware, the system operates 26 snow monitoring systems. In this past storm, Woodside emerged as the top snow-getter with more than 16 inches. (The Woodside location, based on it being the closest municipality, might more accurately be labeled Willow Grove. It is in a meadow off Del. 10 in the Norman G. Wilder Wildlife Area.) It’s not ruler-in-the-snow methodology. Each solar-powered station has a National Weather Service snow board made of non-conductive plastic that keeps the ground’s warmth from affecting the measurement. It uses a sonic depth sensor. “It uses sound to determine the distance to the surface below,” Mr. Brinson said. The station uses cellular communications to update reports. It takes a measurement every five minutes. Additionally, there are built-in algorithms that account for wind, he said. How accurate is it? The stations have been validated with actual ruler on the snow board measurements, Mr. Brinson said. “It’s accurate to within 1 centimeter,” he said. Mr. Brinson said there was a team of people at the University of Delaware that rotated shifts during the 36 hours of the storm last weekend. “We’re very involved in tracking the snow and making sure the best information is available in real time,” he said. When the numbers look suspicious, they look beyond the data of the station for insight. Sometimes, it’s checking the radar and precipitation indicators. Other times, it’s a matter of checking a DelDOT traffic camera to see if the snow really is falling. For the weather experts, there’s really not much difference between a place that got 15 inches and one that got 12. If you broke it down into a liquid equivalent, he said, it’s basically the difference of 1.5 inches of rain and 1.2 inches. “People don’t blink because the numbers are smaller,” Mr. Brinson said. “While it looks like a lot of disparity, it’s actually a fairly even field once you start getting snow.”

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The Delaware Environmental Observing System’s snow monitoring actually has a Delaware transportation use as its primary mission. The measurements are used to determine state reimbursements to civic associations. After the 1995-96 storms that strained associations’ budgets, the state passed a bill to financially assist the neighborhoods. It imposed price controls so that reimbursements did not exceed 75 percent of the amount paid to contractors. The total amount of reimbursements for this past storm may be as much as $997,000, DelDOT spokesman Jim Westhoff said. In Fiscal 2015, DelDOT’s reimbursement total was $788,000, he said. The program, he said, is good for the neighborhoods because plowing is done sooner than the state might get there. And, it’s a boon to small businesses that contract the work. DelDOT turned to DEOS in 2007 to provide measurements and data for the program. In recent years, the monitoring system has made its greatest expansion below the canal. Each DelDOT maintenance area, except Laurel, has two sensors. Laurel, which has no association participating in the state reimbursement program, has just one. Given Delaware’s fairly mild winters, Mr. Brinson said folks around the nation are surprised when they hear about the network in Delaware. “To say there’s nothing like it is an understatement,” he said. “There’s nothing like it nationally and certainly not for this purpose.”

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No doubt, some of you might question whether the snow measurements are correct. After all, if you went out with your ruler you probably could come up with different amounts. “In a storm like this, if you went out there with a ruler, you’d have a difficult time finding a good spot to that hasn’t had a significant effect from the wind,” said Mr. Brinson. So he understands the calls and criticisms they get about the data at times. “Everybody talks about how much they got,” he said. “Sometimes it feels like we’re talking about catching fish.” We’re sure many of you got a feel for the changing nature of the storm as you were shoveling the snow. As you cut through the snow to clear it, you likely noticed the various layers. “Snow is always dynamic,” said Mr. Brinson. “When snow hits and it starts to accumulate, we call that the snow pack. That snow pack has lots of things going on inside of it. Underneath of it, it’s warmer ground so that warm ground is starting to melt from underneath. The snow has weight so as it sits there a while, it compacts a little bit. “So it’s melting a little bit, it’s compacting some. And then another snow layer comes on top. Each band of precipitation is not created equal. You get those layers that show up in a snow pack. It almost looks like a stratification you would see in rock layers.” By the way, Mr. Brinson and this editor laughed about the reality of snow depth. For those shoveling, it is what it is. “Ultimately, that’s what matters most to them,” he said with a laugh. “If I shoveled 18 inches, then daggone it, it’s 18 inches.”