In effect: Saturday, May 02 2026 11:07 AM AKDT – Monday, May 04 2026 10:00 AM AKDT

Issued by NWS Anchorage AK

BREAKUP OUTLOOK

ESFAFC

BREAKUP OUTLOOK IS NOW IN A GRAPHICAL FORMAT:

The graphical Alaska Spring Breakup Outlook products are posted to
the Alaska-Pacific River Forecast Center website at:
www.weather.gov/aprfc/breakupProducts

A direct link to the latest graphical product is:
www.weather.gov/media/aprfc/BreakupProducts/ESFAK_ACR_20260501.pdf

UPDATES FROM THE PREVIOUS SPRING BREAKUP OUTLOOK:

This Breakup Outlook continues to be refined to include more
detailed flood potential and breakup timing information, including
graphics and tables with community-specific flood risk and forecast
breakup dates. Snowpack and ice conditions remain largely unchanged
from the previous outlook, other than noticeable melt-off of
snowpack in lower elevations of the Kuskokwim Delta and Tanana
Valley. While not in full-swing, breakup began with the Kuskokwim at
Nikolai on April 25.


The most notable change is in the spring temperature outlook, which
now favors near-normal to below normal temperatures through the
first half of May. This is a change from the outlook a week ago,
which favored above normal temperatures through early May. This
trend could delay breakup across the state an extra day or two and
is helping maintain ice cover and slow melt out. Climate models do
continue to indicate above normal temperatures the second half of
May. This rapid transition could increase the likelihood of a
dynamic breakup, but timing will be critical. There is a good chance
that widespread breakup will occur before the rapid warmup sets in.
Overall, this combination continues to increase the likelihood of a
more dynamic breakup.

STATEWIDE FLOOD POTENTIAL OVERVIEW:

The breakup flooding potential is above average across parts of
mainland Alaska. In the Interior, the primary areas of concern are
the upper Yukon and lower Tanana Rivers, along with the middle
Kuskokwim River near Crooked Creek and Aniak/Kalskag. Portions of
the middle and lower Yukon, lower Kuskokwim, and the North Slope
also face an elevated risk. This increased threat is driven by a
combination of above-average snowpack, average to above-average ice
thickness, high river levels at freeze-up, rough ice or freeze-up
ice jams reported in several Interior locations, and the delayed
snowmelt from below-average April temperatures. In contrast, the
Koyukuk, Kobuk, and upper Kuskokwim rivers, as well as rivers across
Southcentral Alaska, have a lower breakup flood threat due to below-
average snowpack. Communities are encouraged to review their flood
response plans and preparedness actions in advance of breakup.
Beyond main river ice effects during breakup, snowmelt flooding in
small channels and ponding on frozen ground during warm days is
possible. Ice may block these channels, causing rapid rises, strong
currents, and localized flooding. Use caution when traveling off
main rivers and stay aware of recent weather and river conditions.


ADDITIONAL DETAILS:

The Alaska-Pacific River Forecast Center has updated the format of
its breakup outlook and summary products. The new format has moved
to a graphical presentation, away from the historically text-based
product. The graphical Alaska Spring Breakup Outlook products are
posted to the Alaska-Pacific River Forecast Center website at:
www.weather.gov/aprfc/breakupProducts

Areas Impacted: