Last Winter’s Record Snow Miscalculated At BWI-Marshall
BALTIMORE (WJZ) –High tech, it isn’t. But measuring snow at BWI-Marshall wasn’t measuring up to standards this past winter.
Alex DeMetrick reports that led to confusion and rewriting of the record books.
Last winter broke records for snow— whether you pushed it for a pay check or shoveled just to get out.
The official numbers come from BWI-Marshall, which reports to the National Weather Service. Only the numbers were wrong.
“I think what went wrong was that they were following two different sets of guidelines,” said WJZ Meteorologist Tim Williams. “There’s one guideline for the FAA that the pilots need. There’s another guideline set by the National Weather Service that climatologists need, and they were following one over the other.”
BWI-Marshall’s snow stick is similar to WJZ‘s. The reading for pilots is taken every hour, and then the snow is wiped clear to gauge runway conditions. Those were the numbers passed along.
Instead, what the Weather Service needs are readings every six hours, more representative of what the rest of us are dealing with. The result was numbers going up and then down with a four-inch error.
For meteorologists, “it made giving accurate assessments of how bad the situation was almost impossible,” Williams said.
So now this reporting station will be used at BWI-Marshall, monitored by a new contractor.
“I think someone else is going to be taking care of the FAA requirement,” said Charles Madison, Maryland Environmental Service. “What we’re going to be doing is primarily around the National Weather Service rules.”
But even with re-calculations, last winter was still a monster snow maker.
“In the scheme of things, if you have 77 inches or if you have 81 inches– and there was a difference of about 4 inches at one point–the city is shut down,” Williams said.
And after correction, the snow was still a record.
If you’re keeping track, last winter was the snowiest since 1922.