In an article put out January 7, the Sentinel reported on some of the more notable facets of weather-related trivia for 2015. But according to one resident’s rain gauges, some of the numbers used didn’t quite add up.
Bill Messmer has been tracking local rainfall for some years, maintaining monthly and annual records since 1984. He currently uses two types of rain gauge, an electronic one and a tube which needs to be manually emptied.
“I collect it at my house every morning,” he said. When off-island, he has someone check the readings for him and reset the gauges.
According to Messmer’s calculations, Wrangell actually received over 109 inches of rainfall last year, considerably more than the 65.7 inches logged by the Weather Underground, a figure included in the Sentinel’s climate roundup in January. The online service uses data it collects from several sources, which include airport observation systems, personal weather stations and national systems.
Daily statistics for Wrangell from the National Weather Service had proven unavailable not only for 2015, but for several years prior. Ordinarily the NWS collects data from the airport using an automated weather observation system (AWOS). However, while hourly observations have been coming in, since the beginning of 2012 an incomplete data set has been logged. Key among the missing data sets is rainfall.
At the Juneau NWS office, meteorologist intern David Levin explained the hole is inconvenient, but offset somewhat by other gauges collecting data nearby on the Stikine River, Zarembo Island and at Petersburg.
“It’d be nice to have that long-term data,” he said. “The more we know the better.”
Messmer’s readings differed from those the Sentinel listed in January, though several months last year were still shown to have at least been among the wettest from the past three decades. January, for instance, had seen just over 14 inches of precipitation, which was the highest measured since 1989. April had accumulated 11.36 inches, nearly an inch more than the next-highest year, 1985. By the Weather Underground’s calculations, both months had been record-setters, with 21.05 and 12.31 inches respectively.
May was still held to be the driest on record, with Messmer recording 0.53 inches for the whole month. But July was the wettest recorded from the past 32 years, with 12.43 inches.
Asked about the inconsistencies, Levin explained the placement of gauges can affect their readings. In the Alexander Archipelago, the extreme changes in geography impact the course of air currents and weather patterns, and even relatively close locations can see noticeable differences in readings.
Messmer, who lives at the top of the hill in town facing the Back Channel, recalled a friend had for a while taken daily measurements down at 6-mile Zimovia Highway, and those numbers also did not always match up to his.
“There were differences between there and here,” he said.
NWS is currently looking into how to restore readings from its AWOS at the airport. Another option to improve its coverage of the Wrangell area would be if a volunteer were to sign up for the Cooperative Observer Program (COOP). Nationwide more than 10,000 volunteers take daily observations, which include daily maximum and minimum temperatures, snowfall, and 24-hour precipitation totals. For more information on how to get involved, check out the FAQ page at http://www.nws.noaa.gov/om/coop/.
Reader Comments(0)