Winter Storm in Petersburg Borough, Alaska

Light snow fell during the MLK long weekend across Petersburg with heaviest rates falling on the 15th when the COOP at the airport measured 11.5 inches. This in addition to the snowfall measured the previous 2 days gave a storm total of 16.9 inches. A period of freezing rain was also noted by the airport observer toward the end of the event. A trained spotter called in 7 inches of snow fell over a 12 hour period during the heaviest rates while a social media post shared that 12.5 inches had fallen near Crystal Lake Hatchery.

Over an extended long weekend event, a prefrontal trough followed by a stronger main system with attached moisture plume, delivered first a wave of dry powdery snow with very high snow rations (40:1 to 50:1 in many places). The next wave/front of snow was wetter and difficult to shovel, with some places seeing a period of freezing drizzle in between the two waves. As the 2nd front tracked southward on the 16th, bringing snow to those areas and extending the duration of the event.