Review of Jan. 2016 blizzard preliminary snow totals validates DC measurement

The National Weather Service formed a “snow team” to review reported snow observations due to the historic nature of the event and concerns raised about some of the preliminary measurements. The team reviewed snow totals taken at eight official snow measuring locations between the District of Columbia and New York City. The review included preliminary snow totals and an evaluation of whether the observers followed standard procedures developed by the FAA — based on National Weather Service guidelines — to measure snowfall.

“Snow measurements are extremely difficult to take because precipitation is inherently variable, a problem compounded by strong winds and compaction during a long duration event,” said Louis Uccellini, Ph.D., director of the National Weather Service. “Still, it’s important that we scrutinize questionable measurements and reject those that scientists deem invalid to ensure the public’s continued confidence in the U.S. climate record.”

The team determined that the preliminary snow total of 17.8 inches at Reagan National Airport is accurate. Some felt that the measurement was too low, and others questioned whether proper snow measurement procedures were followed because the snowboard became buried and could not be located during the afternoon of the blizzard. The team validated the reading because the measurement is consistent with totals near the airport. The experienced observer followed official FAA guidelines for measuring snowfall, using an alternate technique that is considered appropriate in the absence of a snowboard.

The preliminary Central Park measurement will be adjusted upward to 27.5 inches, which will become an all-time snowfall record for New York City when certified by NOAA’s National Centers for Environmental Information. A communication error between the weather forecast office in Upton, New York, and the Central Park Conservancy, which volunteers to take official snow measurements in Central Park, led to an inaccurate preliminary total of 26.8 inches. The snow team found the mistake when reviewing the Conservancy’s logbook.

The snow team invalidated the preliminary record measurement of 28.1 inches at New Jersey’s Newark International Airport. The team found that snow was measured hourly instead of the standard procedure of measuring every six hours, which led to an inflated preliminary total. Meteorologists at the National Weather Service will follow a scientific method to determine the accurate total before it is sent to NOAA’s National Centers for Environmental Information for certification. The old Newark snowfall record of 27.8 inches set in 1996 stands.

Preliminary snow totals at the other sites reviewed — Dulles International Airport, Baltimore/Washington International Airport, John F. Kennedy International Airport, LaGuardia International Airport and Philadelphia International Airport — were validated as accurate.

All snowfall measurements and any reported records are considered preliminary until they are certified for the historical record and deemed official by NOAA’s National Centers for Environmental Information. This happens many days to weeks after a weather event.

The snow team comprised seven meteorologists from National Weather Service headquarters, eastern region headquarters and local forecast offices, a member from NOAA’s National Centers for Environmental Information, a member from the FAA, and a representative from the New Jersey state climatologist’s office. The findings and recommendations in this report will serve to inform the broader national service assessment underway that is evaluating overall National Weather Service performance during the east coast blizzard of 2016.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter, Instagram and our other social media channels.