By GARLAND KENNEDY
Sentinel Staff Writer
April may be a spring month, but an unusual – though not unprecedented – amount of snow has fallen on Sitka so far.
In the first ten days, 4.5 inches of snow was recorded, four times the average snowfall for all of April in recent years, National Weather Service Observation Program Leader Kimberly Vaughan told the Sentinel on Monday.
She noted that April snowfall has ranged widely over time.
“April has a wide range from nothing to up to over a foot, yet the average or mean during that time period (1948-1996) only came out to 1.3 inches, because there’s a lot more of those Aprils that had a lot less snow,” Vaughan said. Snowfall record keeping by the National Weather Service, she added, has not been consistent through the years, with a gap in data between 1996 and 2008. This prevents Sitka from establishing a 30-year decadal normal.
April 1 looked like the middle of winter after more than an inch of snow fell overnight. This April is shaping up to be one of the snowiest on record. In the first 10 days of April 4.5 inches of snow was recorded. (Sentinel Photo)
From 2008 to the present, the average total snowfall in April is 1.1 inches, as measured at the Sitka wastewater treatment plant. Up to 1996, snowfall was tallied at the airport.
“This station is very shallow in its data, so its average or its mean is 1.1 for the month of April, so it does make 4.5 seem pretty large… It’s not that extreme, it obviously can happen, but it is unusual,” Vaughan said. The first ten days of April have experienced quadruple the average snowfall than does a typical April in recent years.
A full 30-year dataset is needed to establish a decadal normal.
While recent snowfall in Sitka is well above the average, it is far from the maximum snowfall for April.
In April of 1972, 12.4 inches of snow blanketed Sitka, NWS data indicate.
Significant amounts of wintry precipitation also fell here in the Aprils of 1948, 1963, 1971, and 1985 – more than 4 inches of snow was logged at the Sitka airport during each of those months.
But unusually high snowfall has not been limited to Sitka.
“For Juneau this winter we’ve had 10.3 inches of snow in the month of April so far. Now the mean is only 2.7. When I look at that, that does show a lot more snow,” Vaughan said.
The state has taken notice as well. The Alaska Department of Public Safety extended the period in which drivers may use studded tires on April 7. In a press release, the department wrote that due to uncommonly wintry conditions, drivers in Southeast may continue traveling with studded tires until May 1. Drivers in most of the state, north of 60 degrees latitude, can keep their tires studded until May 15.
In Sitka, Vaughan said, the relatively warm waters of the Gulf of Alaska tend to reduce overall snowfall.
“You don’t think of it as being a warm body of water ... in our wintertime that body of water is relatively warm compared to our air temperature. It’s basically like having this little heat source. Sitka – and any of those outer coastal stations – really benefit from that feature,” she said.
