– Alaska records one of the most extreme snowfall rates on record:
An astonishing 25.4 cm (10 inches) of snow per hour was reported at Thompson Pass near Valdez, Alaska on Wednesday, December 6, 2017. This is extraordinary even by Valdez standards, the snowiest town in the United States.
What hit Alaska’s North Gulf Coast this week, producing one of the most extreme snowfall rates on record is what meteorologists like to call a “snow AR” or an atmospheric river that is producing snow instead of rain.
On Wednesday, December 6, this storm dropped 12.7 cm (5 inches) of snow at Thompson Pass in 30 minutes, 25.4 cm (10 inches) in 60 minutes and 38.1 cm (15 inches) in 90 minutes. Within 72 hours (between December 3 – 6, 13:00 local time), the National Resources Conservation Service (NRCS) SNOTEL site at Nicks Valley at 1 300 m (4 280 feet) picked up 210.8 cm (83 inches) of snow, making a total of 320 cm (126 inches).
According to a quick analysis by Weather Underground’s weather historian Christopher Burt, Thompson Pass storm ranks among the most intense snowfalls we know of. Burton told John Hopewell of Capital Weather Gang, that on December 2, 1966, 30.48 cm (12 inches) fell in 60 minutes in Copenhagen, N.Y., and on January 26, 1972, Oswego, N.Y., recorded 44.45 cm (17.5 inches) in a two hour period. Both of these records were the result of a lake effect snow.