A late season record snow event occurred in Anchorage on April 25th, 2008. The 15.5 inches that fell at the Anchorage forecast office on April 25th was not only the biggest April snowfall ever recorded, but the third heaviest one day snowfall amount on record. Storm totals around Anchorage ranged from 17.2 inches at the forecast office to multiple reports of 22 inches in east Anchorage.
Conventional wisdom was that the snow should not accumulate significantly during the day in late April. The big question is: Why did that happen? In summary, this event was due to a strong cold front stalling just east of Anchorage Friday morning while a warm conveyor belt advected saturated air over Anchorage. The heavy snowfall that resulted from this did not stop until a low developing in the Gulf of Alaska was able to force the front back to the west on Saturday. The vertical extent of the cloud cover and cooling of the air column enabled the surface temperatures to drop to where snow could accumulate at a rapid pace. Model forecasts were actually very good with the overall pattern but the placement of the cold front was in question. Everything had to come together in a way that has never before been observed in Anchorage this late in the season. It however did, and we received the third heaviest one day snowfall amount in the history of Anchorage as a result.