Juneau faces flooding risk as atmospheric river follows its snowiest December in more than 80 years, Alaska
After its snowiest December in more than eight decades, Juneau, Alaska, now faces flooding threats as warm Pacific air brings heavy rain over deep snow. The National Weather Service (NWS) warns that clogged drains and rapid snowmelt could trigger flooding in streets and small streams through the weekend.
Satellite image of atmospheric river impacting Alaska at 15:30 UTC on January 9, 2026. Credit: NOAA/GOES-West, RAMMB/CIRA, The Watchers
Juneau experienced its snowiest December in more than 80 years, with total accumulation reaching about 2.1 m (82 inches).
The dense, wet snow caused significant structural and marine damage, including multiple roof collapses and at least eight sunken vessels in local harbors. Schools, businesses, and public facilities were closed as crews worked to clear heavy snow.
The City and Borough of Juneau and the Central Council of the Tlingit & Haida Indian Tribes of Alaska issued a joint local disaster declaration on January 7, later supported by a verbal state disaster declaration from the Governor’s Office. The declarations allow coordination of state assistance for damage assessment and snow removal operations.
Only two days later, the next phase of the event began to unfold. An atmospheric river and its associated frontal boundary made landfall across the Alaska Panhandle by 14:00 UTC (05:00 LT) on Friday, January 9. Areas near and north of Icy Strait reported very low visibility and heavy snow, while the southern panhandle experienced reduced visibility in rain.
As of January 9, the National Weather Service (NWS) in Juneau forecasts a sharp transition from cold, snowy weather to a warm, moist pattern driven by a Pacific atmospheric river. In its 06:00 AKST forecast discussion, NWS stated that “a Flood Watch is in effect for [the] majority of the panhandle… with moderate to heavy rainfall possible.”
“An atmospheric river is on our doorstep with the associated warm front currently entering the southern and central Panhandle area,” NWS Juneau meteorologists said. “Temperatures across the central and southern panhandle have warmed into the upper 30s to low 40s with the changeover to rain ongoing along and south of a line from Sitka to Petersburg.”
“This system will be responsible for multiple waves of precipitation and a complicated series of hazards moving through Friday and into Saturday.”
Forecast totals indicate 25–40 mm (1–1.5 inches) of rain across the northern panhandle, increasing to 50–115 mm (2–4.5 inches) and locally up to 150 mm (6 inches) farther south.
Rapidly rising freezing levels are expected to accelerate the melting of the existing snowpack.
The southern panhandle is expected to receive the majority of the rainfall. The first surge of energy associated with the initial warm front will bring strong winds to the southern half of the panhandle, with gusts up to 80 km/h (50 mph).
A secondary surge from a shortwave moving along the main moisture axis will merge with the initial energy impacting the panhandle. This secondary wave is expected to destabilize the lower levels of the atmosphere enough to mix down gusts reaching 95 km/h (60 mph) across the extreme southern panhandle, including Hydaburg, Ketchikan, and Metlakatla.
The central panhandle and Icy Strait corridor are forecast to begin with snowfall, producing an additional 2.5–7.5 cm (1–3 inches), with locally higher amounts possible near Icy Strait, including Juneau. The probability of snowfall exceeding 15 cm (6 inches) is currently estimated at about 10%, particularly as the lower atmosphere near Juneau remains partially mixed.
This will allow warm air advection from the advancing warm front to reach the surface quickly, transitioning precipitation from snow to rain. The transition is expected between 07:00 and 12:00 LT on Friday morning, coinciding with the morning commute. By that time, snow levels will rise rapidly to above 760 m (2 500 feet), temperatures will increase, and precipitation will shift predominantly to rain.
For the northern panhandle, the timing of the transition remains significantly more uncertain, as reflected in the winter storm product issued earlier today.
Model guidance varies between Friday afternoon and overnight into Saturday, with the most probable changeover occurring Friday evening. Snowfall totals remain somewhat higher to account for the possible extended duration of the snow event. Along major highways, a brief period of mixed precipitation is expected, which may compact existing snow accumulations before returning to snow above roughly 300 m (1 000 feet).
The NWS Flood Watch bulletin warns that “storm drains and ditches are clogged with snow… [which] may cause ponding of water in these poor drainage areas.” Urban and low-lying locations are at the highest risk of flooding as rainfall combines with snowmelt.
Localized street and small-stream flooding is anticipated, with possible minor landslides on steep slopes where rainfall is heaviest. Broader river flooding, including within the Mendenhall River basin, will depend on the duration and intensity of rainfall and melt rates.
City officials have urged residents to clear roof drains and move snow away from buildings while crews continue to open storm drains and monitor avalanche control zones. The City and Borough of Juneau advised the public to stay alert for changing conditions as rain intensifies through the weekend.
The long term period continues with active weather for the panhandle. The onshore flow will continue with another low expected to move into the Gulf of Alaska for Sunday, January 11, which will bring another round of precipitation to the panhandle. Most of this is expected to be rain for most locations at sea level, with the exception of maybe some snow for the northern Lynn Canal area.
References:
1 Southeast Alaska Forecast Discussion – NWS/Juneau – January 9, 2026
I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.
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