793
NOAK49 PAFG 101927
PNSAFG
AKZ838>845-110730-

Public Information Statement
National Weather Service Fairbanks AK
1127 AM AKDT Sat May 10 2025

...2025 GREEN-UP ON CHENA RIDGE...

Green-up on Chena Ridge has been viewed from the National Weather
Service Forecast Office on the UAF campus on May 10, 2025. Last
year, green-up occurred May 4th. The climatological median for the
day of green-up, from the past 50 years, is May 8th. The earliest
recorded day of green-up in the last 50 years was back in 2016
when it occurred on April 26th, and the latest was on May 26,
2013.

Green-up in Interior Alaska is the sprouting of tree (birch and
aspen) leaves in the spring. In many years it is quite abrupt,
with entire hillsides "greening" up in just a day or two. Green-up
occurs earliest on the lower slopes of south facing hillsides,
spreading rapidly down to the valley and more slowly upslope.

This event is important meteorologically because evapo-
transportation rapidly increases, resulting in higher water
content in the boundary layer of the atmosphere.

$$

Chriest/Twombly/Santiago