Cold and Snow

Here's a bit of follow-up on the unusually late cold and snow.  According to Rick Thoman (and relayed via Brian Brettschneider on Twitter), Monday's half-inch of snow in Fairbanks was the first time since 1978 that measurable snow occurred after green-up.

The late snow in 1978 was much later - May 27 - but it was also more marginal, with mixed rain and snow reported, and officially-measured accumulation of only 0.1".  A more legitimate late snowfall occurred in 1966 in Fairbanks, with 1.6" measured on May 15-16; that was 8 days after breakup at Nenana, and almost certainly after green-up too (although the NWS green-up history only goes back to 1974).

Not to be left out, Anchorage also saw accumulating snow on Wednesday night.  This is a top-10 latest date for snow, and it's actually the latest on record with measurable snow on the ground at the daily observation (data back to 1953).  The previous record was May 6, 1955.  Interestingly last year there was snow on the ground on May 4.

The cold hasn't stopped breakup from proceeding, however.  The ice went out on the Yukon River at Tanana on Wednesday, and the Kuskokwim tripod at Bethel stopped the clock on Wednesday morning, despite a temperature of 25°F with snow falling.  Unfortunately significant flooding is now occurring in Bethel and elsewhere on the lower river, as the ice is jammed up downstream.

https://www.kyuk.org/public-safety/2024-05-09/as-lower-kuskokwim-river-breaks-up-bethel-sees-highest-river-gauge-level-in-almost-20-years

On the other side of the Arctic, very unusual cold is also affecting western Russia; it was snowing in Moscow yesterday for their big parade.  Severe freezes have also occurred in the Baltic states in recent days - a rare event for this late in the season.  As I commented in my last post, I think the "perturbed" flow pattern can be traced back to the lingering circumpolar disruption caused by the March stratospheric warming event.