Remember when Al Gore and Katharine Hayhoe told us that a record snowfall in Erie, PA was proof of global warming? Never mind.
From Al Gore’s “climate reality project” article: A ‘PERFECT STORM’: EXTREME WINTER WEATHER, BITTER COLD, AND CLIMATE CHANGE
Let’s start with the record five-plus feet of snowfall accumulation in Erie, Pennsylvania, in late December. Does this disprove global warming? “Exactly the opposite,” explains my colleague, Dr. Katharine Hayhoe of Texas Tech University.
Global warming is leading to later freeze-up of the Great Lakes and warmer lake temperatures. It is the collision of cold Arctic air with relatively warm unfrozen lake water in early winter that causes lake effect snows in the first place. The warmer those lake temperatures, the more moisture in the air, and the greater potential for lake effect snows. Not surprisingly, we see a long-term increase in lake effect snowfalls as temperatures have warmed during the last century.
But wait, that 50″ record has just been, ahem, denied.
A State Climate Extremes Committee has nullified the 24-hour and monthly Pennsylvania State snowfall records from Erie in December, 2017, due to questionable measurement practices.
On 14 February and 9 April 2018, a State Climate Extremes Committee (SCEC) convened to verify /
validate a report of a 50.8 inch snowfall in Erie, Pennsylvania over the 24-hour period spanning 25-26
December 2017. In addition, the total snowfall accumulation for the month of December in Erie
measured 120.9 inches. If verified, the 24-hour snowfall and monthly maximum snowfall would become
new records for the state.
The committee considered the following factors in their decision: the genuine nature of the measured
snowfall, meteorological plausibility, and methods and practices of observation. After reviewing the
observational evidence, the SCEC voted (1-4) against accepting both the 24-hour snowfall and the
monthly accumulated snowfall values. In particular, the committee could not, beyond a reasonable
doubt, find the following snowfall amounts to be true and valid:
• LOCATION: Erie, PA International Airport (COOP ID: 362682)
• DATE: 25-26 December 2017
• SNOWFALL: 50.8 inches (24-hour)
• DATE: December 2017
• SNOWFALL: 120.9 inches (monthly total)
The SCEC-recognized 24-hour snowfall record of 38 inches occurred on 20 March 1958 in Morgantown,
PA. The record for monthly maximum snowfall of 117.8 inches was reported in Laurel Summit, PA
during February 2010. These values remain intact as the statewide records for Pennsylvania.
Review of Observing Practices & Equipment
The paid snow observer, who is not with the Federal Aviation Administration (FAA), did not have experience measuring snowfall at the airport prior to that which fell during December 2017. Their first snow measurements occurred at the Erie Airport on 7 December 2017. NWS CLE indicated that all five observers were either trained by NWS personnel or provided with instructions, which were left with their manager, to train the remaining personnel prior to measuring snowfall. NWS CLE personnel indicated there was not sufficient time following the retirement of the previous observer to provide optimal training for all of the new observers. In addition, NWS CLE had a vacancy in their data collection unit since June 2016, which was also a contributing factor to less than optimal time for training new snow observers. These observers were familiar with and instructed to follow the NWS snow measuring guidelines. During the training, one snow board was designated for new snowfall and marked with a snow stake and traffic cone nearby (Figure 3). Snow was officially measured and the board was cleared 4 times per day. During the training, snow depth was explained as the total depth of snow on the ground at the time of observation and the observers were encouraged to get a snow depth by measuring snow in untouched areas that were representative of the total snow on the ground. The observers were told
that sometimes an average depth would be appropriate if conditions were particularly windy and significant drifting was occurring. In addition, a second snow board was placed in the “triangle-shaped” area that could also be utilized for snow depth purposes (Figure 4).
NWS officials learned the following about the observing practices which occurred during the event on 25-26 December 2017:
– A traffic cone was used to stabilize the snow board from blowing due to high winds. Although resourceful, this practice may have impacted the snowfall accumulation (Figure 5).
– The snow board was always placed on top of the snow after a measurement was made, although there was higher snow around the board, allowing for a cratering effect.
– The snow board did not always make it on top of the highest snowpack after each clearing.
Snowfall reported by other observers in the Erie metropolitan area near the airport location reported 18 to 22 inches less snowfall over the 24-hour period in question. (Figure6)
h/t to Dr. Ryan Maue
via Watts Up With That? https://ift.tt/1Viafi3